Internet censorship in Iran

ifmat - internet censorshipinIran

Internet censorship in Iran

Internet censorship in Iran has been increasing. In the first few years of the 21st century, Iran experienced a great surge in Internet usage. As of 2013, Iran has 46 million Internet users with a penetration rate of 61.57%. As of 2012, an average of 27% of internet sites were blocked at a given time and as of 2013 almost 50% of the top 500 visited websites worldwide were blocked, including YouTube, Facebook, Twitter, and Google Plus. The blocked sites have a wide range of topics including health, science, sports, news, and shopping. At the beginning of March 2012, Iran began implementing an internal Intranet.

The Iranian Government has developed a centralised system for internet filtering, created institutions tasked with monitoring Internet use and censorship of content, engaged the Revolutionary Guard Corps in enforcing Internet content standards, and entrenched many of these practices through legislation in the Computer Crimes Law. While certain rights to freedom of expression are held within the Iranian constitution, a number of provisions within both the constitution, the penal code, and the press laws aim to restrict these values based on vague and often arbitrary principles meant to shield ‘Islam’ or ‘national security’, with very little regard to proportionality.

According to recent statistics published in May 2017 by the Ministry of Communications and Information Technology (ICT) , the total number of fixed broadband users in Iran summed up to 10 million users, and the total number of mobile-broadband users summed up to 41 million users. TechRasa’s recent survey included 3,707 Iranians between the ages of 18 to 65, with 2,829 men and 878 women. According to their survey, 80% of participants have an account on Telegram and 50% have an account on Instagram. 20% of participants reported that they have an account on Facebook, even though it is blocked in Iran. As for the frequency of use of social media and messaging apps, participants reported that they use Telegram the most (80%), while Instagram is used more than 40%, Facebook over 10% and Twitter more than 5% as frequently.

Internet service providers

Every ISP must be approved by both the Telecommunication Company of Iran (TCI) and the Ministry of Culture and Islamic Guidance, and must implement content-control software for websites and e-mail. ISPs face heavy penalties if they do not comply with the government filter lists. At least twelve ISPs have been shut down for failing to install adequate filters.The state blacklist consists of about 15,000 websites forbidden by the Iranian government. Before subscribers can access Internet service providers, they must first promise in writing not to access “non-Islamic” sites. In 2008, Iran has blocked access to more than five million Internet sites, whose content is mostly perceived as immoral and anti-social.

Blocked domains in Iran

Thousands of ooniprobe network measurements collected from 60 local networks across Iran over the last three years have confirmed the blocking of 886 domains (and 1,019 URLs in total).
The breadth and scale of internet censorship in Iran is pervasive. Blocked domains include:

Opposition sites:People’s Mojahedin Organization of Iran, Worker-Communist Party, Labour Party (Toufan), Komala Party of Iranian Kurdistan, National Council of Resistance of Iran (NCRI).
Pro-democracy sites:National Democratic Institute (NDI), National Endowment for Democracy (NED).
Blogs of Iranian political activists:Ali Afshari and Ahmad Batebi.
Human rights sites:Center for Human Rights in Iran, Human Rights & Democracy for Iran, Iran Human Rights, Human Rights Watch, Human Rights Campaign, Human Rights First.
Kurdish,, Kurdish Human Rights Project.
Women’s rights sites:,, AWID.
LGBTQI sites:Grindr,,, ILGA.
Sites promoting freedom of expression:Free Expression Network (FEN), Free Speech TV, Committee to Protect Journalists, Freedom House, Reporters Without Borders, ARTICLE 19.
Digital rights groups:ASL19, The Citizen Lab, Herdict, Global Voices, Electronic Frontier Foundation (EFF), The Centre for Democracy and Technology (CDT).
Media sharing,,,,,
Anonymity and censorship circumvention tool sites:,,,,,,,,

Facebook Messenger was blocked using DNS manipulation. In contrast, other popular communications apps, like WhatsApp and Telegram, were accessible during the testing period.

Internet censorship in Iran is quite sophisticated. ISPs regularly block both the HTTP and HTTPS versions of sites by serving blockpages through DNS injection and through the use of HTTP transparent proxies. Most ISPs not only block the same sites, but also use a standardized set of censorship techniques, suggesting a centralized censorship apparatus.
Internet censorship in Iran is non-deterministic. Many observations flipped between blocking and unblocking sites over time, possibly in an attempt to make the censorship more subtle.


Network landscape

Internet gateways into Iran are managed by the Telecommunication Infrastructure Company (TIC) which maintains a monopoly, and is managed by the Ministry of Information Communications and Technology. The TCI also owns the Data Communication Company of Iran (DCI), which is the main ISP of the country. Of greatest concern within this infrastructure (visualized in the infographic from ONI below) is the fact that a consortium of private businesses owned by the paramilitary institution of the Revolutionary Guards (known for their arrests, surveillance, and repression of human rights defenders, journalists, bloggers, and internet users exercising their rights to freedom of expression online) owns about 50% of the shares of the Telecommunications Company of Iran (which operates the TIC) when the government attempted to privatize it in 2007.


Source: After the Green Movement: Internet Controls in Iran, 2009-2012, OpenNet Initiative

This is of great concern as the Revolutionary Guards effectively yield significant influence over the company that routes all the internet traffic through the country. As ONI wrote in 2013, “This single point of connection makes it easy for the government to control the Internet and effectively filter it either by blocking webpages or blacklisting keywords.”

Below we include some observations on Iran’s ASN infrastructure based on BGP interactions data from RIPE and CAIDA.

The following ASes on the border of Iran’s network to rest of the world, with the first two controlling more than 90% of the connections.

Telecommunication Infrastructure CompanyName
AS48159Telecommunication Infrastructure Company
AS12880Information Technology Company (ITC)
AS203100Iman Samaneh Sepehr LLC
AS62229Fars News Agency Cultural Arts Institute
AS39200Research Center of Theoretical Physics & Mathematics (IPM)
AS58262Nrp Network LLC
AS44932Fannavaran-e Idea Pardaz-e Saba PJSC
AS6736Research Center of Theoretical Physics & Mathematics (IPM)

The above ASes are connected to:

Telecommunication Infrastructure CompanyNameCountry
AS29049Delta TelecomAzerbaijan
AS200612Gulf Bridge InternationalUAE
AS6453Tata CommunicationsUS
AS34984Super OnlineTurkey
AS1273Vodafone Group PLCUK
AS6762Telecom Italia Sparkle S.p.A.Italy
AS3491Beyond The Network America, Inc.US
AS15412Flag Telecom Global InternetUK
AS4436nLayer CommunicationsUS
AS3257GTT Communications Inc.Germany
AS33891Core BackboneGermany
AS12212Ravand Cybertech Inc.Canada
AS59456Cloud Brokers IT Services GmbHAustria
AS42926Radore Veri Merkezi HizmetleriTurkey
AS60068Datacamp LimitedUK

The following ASes are acting like an internal hub with more ASes connected to them but don’t have direct connection to international networks:

Telecommunication Infrastructure CompanyName
AS24631Tose’h Fanavari Ertebabat Pasargad Arian Co. PJS
AS12880Information Technology Company (ITC)
AS44889Farhang Azma Communications Company LTD
AS41881Fanava Group
AS59587PJSC “Fars Telecommunication Company”

The following International ASes import BGP data from Iran’s ASes.

Telecommunication Infrastructure CompanyNameCountry
AS198398Symphony Solutions FZ-LLCUAE
AS131284Etisalat AfghanAfghanistan
AS45178Roshan AFAfganistan
AS55330Afghanistan Government Communication NetworkAfghanistan
AS41152Ertebatat Faragostar Sharg Company, PVT.UAE
AS36344Advan Technologies LLCUS
AS25152RIPE NCCNetherlands
AS3177Visparad Web Hosting Services LLCEU
AS47823Mohammad MoghaddasGermany

The above international ASes are connected to the following ASes.

Telecommunication Infrastructure CompanyName
AS16322Pars Online PJS
AS48159Telecommunication Infrastructure Company
AS43754Asiatech Data Transfer Inc PLC
AS42337Respina Networks & Beyond PJSC
AS31549Aria Shatel Company Ltd

Research on Iran’s network infrastructure has revealed the presence of a “hidden internet”, with private IP addresses allocated on the country’s national network. Telecommunications entities were found to allow private addresses to route domestically, whether intentionally or unintentionally, creating a hidden network only reachable within Iran. Moreover, the research found that records such as DNS entries suggest that servers are assigned both domestic IP addresses and global ones.

This section explores the Iranian laws pertaining to freedom of expression and the press, via an analysis of three key legal documents: the Constitution of the Islamic Republic of Iran, the Press Law, the Penal Code, Computer Crimes Law. Additionally, the erosion of freedom of expression can be seen through the institutionalisation of censorship bodies. Overall, legal protections for freedom of expression and the press are somewhat ambiguous: rights are formally enumerated, while the opportunities in which they may be exercised are restricted. To unpack this tension, we turn to a few key passages from the Iranian constitution.

The 1979 Constitution of Iran protects the rights to free expression, peaceful assembly and association in Articles 24, 26, and 27 respectively, but also permits these rights to be curtailed in circumstances not compatible with the ICCPR. These include very vague terms that are not defined, enabling arbitrary restrictions on the exercise of these rights:

Freedom of expression can be restricted if it is found to be “detrimental to the fundamental principles of Islam or the rights of the public” (Articles 20 and 24);

Article 40 prohibits the exercise of constitutional rights in a manner deemed to be “injurious to others” or “detrimental to public interests”;

The preamble of the Constitution specifies that the media must “strictly refrain from diffusion and propagation of destructive and anti-Islamic practices”.

The Penal Code (IPC) contains broad provisions criminalising expression that are against international human rights law; including criminal insult and blasphemy provisions, criminalisation of disseminating ‘propaganda against the State’, spreading false rumours, lies, and creating “anxiety and unease in the public’s mind” (Book One, Article 286). Penalties include prison sentences, flogging, and even death. Together with other vague and overbroad provisions, such as “acting against national security”, “membership in an illegal organization”, and “participation in an illegal gathering” these provisions are arbitrarily interpreted to criminalise journalists, bloggers, human rights defenders and minority groups as well as others legitimately exercising their rights.

The Press Law: Article 24 of the Constitution protects press freedom, but not for media deemed “detrimental to the fundamental principles of Islam or the rights of the public”. Combined with the repressive Press Law, severe restrictions on media freedom remain the norm (read more about the Press Law here).

Examples of problematic provisions of the Press Law include:

Article 2 requires the press to pursue at least one of five “legitimate objectives”, which include “to campaign against manifestations of imperialistic culture” and “to propagate and promote genuine Islamic culture and sound ethical principles”;

Articles 6 prohibits the publishing of an exceptionally broad spectrum of content including atheistic articles, those prejudicial to Islamic codes, insulting Islam and/or its sanctities, offending senior Islamic jurists, those quoting articles from the “deviant press” or groups which are seen as opposing Islam, or any publication deemed contradictory to the Constitution;

In October 2016, President Rouhani’s administration proposed a new bill (the ‘Comprehensive Mass Media Regulation’) to replace the current Press Law that will impose greater restrictions on media freedom. If introduced, the bill raises concerns as it gives more leeway to judges and prosecutors to determine whether an offence has been committed, thereby facilitating the politically motivated judicial harassment of journalists and newspapers both offline and online.

The Computer Crimes Law: Adopted by the Parliament in January 2010, the Computer Crimes Law is saturated with provisions that criminalise legitimate expression in the digital space, including draconian content-based restrictions designed to allow the State to exert unfettered control in the sphere where its authority is most frequently challenged.
Among the content-based restrictions targeting online expression are the offences against “public morality and chastity” (Articles 14 and 15) and the “dissemination of lies” (Articles 16 – 18) that are engineered to ensnare all forms of legitimate expression. These include broad defamation and obscenity provisions that are antithetical to the right of freedom of expression. Essential elements of offenses are described with ambiguity and in vague and overbroad terms, giving the government unfettered discretion to pursue its own prerogatives above the interests of the public and the standards set by the international human rights law.

The Computer Crimes Law mandates severe sentences that penalise legitimate expression and offend the principle of proportionality, without defences for individuals acting in the public interest. The availability of the death penalty for crimes committed online against public morality and chastity is particularly abhorrent. Other sanctions include lengthy custodial sentences, excessive fines, and judicial orders to close organisations and ban individuals from using electronic communications. These penalties also apply to Internet Service Providers that fail to enforce content-based restrictions, incentivising the private sector to promulgate Iran’s censorship culture.

The institutionalisation of online censorship: A number of regulatory bodies with extremely opaque structures have been founded since 2009 with mandates to restrict access to and use of the internet. These bodies can be divided into three tiers: the first constituting high-level policymaking councils; the second made up of executive decision-making bodies; and the third including a range of enforcement agencies.

Policymaking: The principal policymaking body is the Supreme Council on Cyberspace (SCC), which develops Iran’s domestic and international cyber policies, with members including Iran’s President and the Head of the Judiciary. This council is overseen by the Supreme Cultural Revolution Council (SCRC) which was set up in 1980, and the Supreme Leader is only person who can overrule their decisions. The SCRC is dominated by Islamic fundamentalists, based in the city of Qom, and made up of the clerical elites making strategic decisions influencing the Supreme Leader. The President of Iran is the ex-officio chairman of the Council.

Executive decision-making bodies: This tier includes executive decision-making bodies such as the Committee Charged with Determining Offensive Content (CCDOC), and the Ministry of Information and Cultural Guidance (MICG).
The CCDOC identifies sites that carry prohibited content, communicates the standards to be used in identifying unauthorised websites to the Telecommunication Company of Iran (TCI), other major ISPs and the Ministry of Communication and Information Technology and makes website blocking decisions. The public may ask the CCDOC to block or unblock a website via an online request form. The final decision will be made by the Committee. The precise number of blocked websites in Iran is not publicly available.

In January 2010, the CCDOC issued a “list of Internet offences” which would lead up to blocking a website. The list is very long and targets a wide range of areas, including anything that is contrary to “the public morals and chastity,” “religious values” and “security and social peace,” and anything that is “hostile towards government officials and institutions” or which “facilitates the commission of a crime,” including circumventing censorship or bypassing filtering systems. It also lists “criminal content in relation to parliamentary and presidential elections”.

The CCDOC is not independent of the Government but is an arm of the Executive. It is headed by the Prosecutor General, and its other members are representatives from 12 governmental bodies. Key members include the Chief of Police and representatives of the Ministries of: Intelligence; Islamic Guidance; and Communication and Information Technology. International standards require that the determination of what content should be blocked should only be undertaken by a competent judicial authority or body which is independent of political, commercial or other unwarranted influences to ensure that blocking is not used as a means of censorship.

The SCC and the CCDOC also have seven members in common, which allows for policy diffusion and institutional alignment.

Enforcement agencies: A number of enforcement agencies are responsible for taking action against offenders. Iran’s Cyber Police unit (FATA), tasked with fighting “digital criminals”, is the most notorious. In the chain of command of internet censorship in Iran, FATA is the policing body that acts on information provided by the SCC and CCDOC.

Reported cases of internet censorship

Iran’s censorship system is one of the most sophisticated in the world. Over the years, since the introduction of the internet in Iran, the government has employed different methods to censor it and its censorship methods have progressively become more complicated. Here we present a list summarizing the methods that have been employed so far mainly based on literature review done by TAAP16 and AAH13.

Originally the government delegate the task of censorship to the ISPs to deploy a IP and keyword based censorship system, moving to a hybrid of central/ISP based system and eventually after 2009 moving to a central censorship system. With the popularity of servers hosting multiple sites and the introduction of CDNs, it moves away from blocking IPs and relies on censoring host names in HTTP or SNI requests. It also uses throttling via packet dropping to deter people from services which host a mix of undesirable and benign content such as Amazon S3 services.
While maintaining mainly a blacklist system, censorship has been more aggressive during politically sensitive occasions, such as days leading to organized protests or elections, and engaged in protocol blacklisting or even white listing. In 2012, for brief period of time, Iran blocked TLS protocols by identifying the TLS handshake. During the months leading up to the 2013 presidential election, the censor first throttled encryption protocols, such as TLS and SSH. During the days leading up to the election, the censor only whitelisted HTTP protocol and throttled any other (known or unknown protocol) to the level of dropping after 60 seconds.

Iran also targets censorship circumvention tools. Tor connections, for example, have been blocked by various methods, including the blocking of the Tor directory authorities, identifying the DH prime used in Tor TLS handshake, singling out the TLS certificate validity length etc. Iranian ISPs have also actively participated in Psiphon client-server negotiation protocol for receiving new proxy IP addresses and effectively blocking Psiphon’s proxies. A new law by the Supreme Council of Cyberspace (SCC) entitled “Policies and Actions Organizing Social Media Messaging Applications” (see Article 19’s translation on page 13 here), created a new legal framework to coerce controls online in the absence of technical censorship capabilities.

Recent efforts that have been tracked by researchers have followed the technical and policy implications of the “intelligent filtering” project. The project was initiated under the Ahmadinejad government with the intention to unblock a number of currently censored platforms such as Facebook and Twitter through targeted censorship. However, because of the difficulties of HTTPS blocking, the project only experienced technical implementation through Instagram. Investigations into the content and type of blocking by Frederic Jacobs and Mahsa Alimardani eventually led to Instagram enabling HTTPS on its mobile application (previously only available on the web browser) in order to limit this type of targeted censorship.
Following the initiation of Instagram encryption across both web based and mobile application based access, there were some cases of select images not being accessed in Iran. Preliminary investigations by the University of Amsterdam’s Digital Methods Initiative indicated this to be collateral damage from Content Delivery Networks (CDN) that Instagram shared with it’s parent company, Facebook, which is blocked in Iran. As of February 2016 however, the government has announced they are devoting \$36 million USD to the development of “intelligent filtering.” According to the New York based human rights NGO Campaign for Human Rights in Iran (CHRI) there is very “little likelihood of smart filtering capabilities inside of Iran.”
While technical capabilities for Iranian censorship do not extend beyond entire platform blocks, Iran’s strongest tactics have been in account seizures and in attempting to incentivize companies to cooperate with them. For Telegram, for example, the foremost messaging and social media application for Iranian users, with over 40 million monthly users (statistic is from Telegram founder Pavel Durov), the government has been able to physically takeover certain accounts through arrests and detentions of the administrators running Telegram channels. The government has also worked to institutionalize incentives for platforms such as Telegram to cooperate with the government, as opposed to implementing technical means to control them. An unsuccessful ultimatum to all foreign technology companies was given in 2016, which gave a year to applications such as Telegram to either comply with authorities, and bring all data for Iranian users into the country (with possibly government oversight) or face censorship.


Thousands of network measurements collected from 60 local networks over the last three years reveal pervasive levels of internet censorship in Iran.

We confirm the blocking of 886 unique domains (and of 1,019 URLs in total) due to the presence of block pages. Some Iranian ISPs served block pages through DNS injection, while others used HTTP transparent proxies to serve block pages.
Internet censorship in Iran does not appear to be deterministic. We noticed that various ISPs would block sites inconsistently across time, possibly creating public uncertainty on whether sites were in fact blocked or not. As such, some of the blocked domains presented in this study have been blocked and unblocked in various moments across time over the last three years.

Most of the blocked domains include news outlets and human rights sites, as illustrated in the graph below.

ifmat - Blocked domains in Iran

Blocked domains in Iran

We have characterised the levels of internet censorship in Iran as “pervasive” because we found a large portion of content falling under many categories to be blocked. The above graph illustrates that internet censorship in Iran is not restricted to illegal forms of content (such as pornography, gambling, hate speech, alcohol and drugs), but also extends to a broad range of other types of content, such as news outlets, human rights sites, blogging platforms, online social networks, communication tools, anonymity and censorship circumvention tools, and search engines, amongst others.

Blocked domains and tools

The levels of internet censorship in Iran are pervasive since a variety of different types of sites were found to be blocked, expanding beyond those that host illegal content. Most of the blocked domains include news outlets and human rights sites, though the limited amount of sites tested and the bias in their selection may have influenced this finding. In any case, a wide range of sites, beyond those that are illegal, were found to be blocked in the country.

Popular search engines, such as and privacy-enhancing, were amongst those found to be censored. Blogging platforms, like,,, and were also blocked. Iranian ISPs even targeted a variety of online gaming sites, such as World of Warcraft. While the precise motivation behind this blocking is quite unclear to us, it might be worth noting that World of Warcraft has been monitored by the NSA over suspicions that the game was used as a communications platform by terrorists.

Multiple Israeli domains were found to be blocked. These include government sites, news outlets (, sports sites (, a mail provider ( and multiple other types of Israeli sites. The fact that the blocking of Israeli domains is not limited to those that express criticism towards the Iranian government or which host illegal content suggests that Iranian ISPs likely blocked Israeli domains almost indiscriminately, regardless of their content. The breadth of Israeli domain blocking also indicates that politics likely influence how information controls are implemented in Iran. Quite similarly, the blocking of and suggests that the political relations between Iran and the U.S. may have influenced internet censorship in the country.

We have found many sites to be blocked as part of this study even though they are no longer active, whether that is because they are censored (preventing site owners from publishing new content), their servers are down, or because the domains are squatted.

In the following subsections we highlight some of the blocked sites and tools.

News websites

As part of this study, we found 121 news outlets to be blocked across Iran over the last three years. These include internationally popular media sites, as well as Iranian news outlets.

Some of the blocked international news sites include: | | | | | | | | | | | | | |

Many of the blocked international news outlets express criticism towards the Iranian government and its regime, likely explaining the motivation behind their censorship. We also found Reddit, an internationally popular site that aggregates news and provides a platform for discussions, to be blocked as well.
Iranian ISPs were found to be blocking (at least) five BBC domains:,,,, and This may not be surprising given that the news agency was previously banned from reporting in Iran for six years, following its reporting on unrest in Iran in the aftermath of the 2009 presidential election. The BBC’s Farsi service was also reportedly blocked more than ten years ago. More recently, Iranian authorities issued a court order imposing an asset freeze on 150 Iranian BBC journalists and former contributors due to their affiliation with the British media organization.

Some Iranian news outlets found to be blocked include: | | | |

Iranshahr is the “first news agency for Iranians abroad”. It reports on international news, but it also has an entire section dedicated to news from Iran which may be viewed as overly critical towards the Iranian government, potentially motivating its blocking by local ISPs. TehranReview serves as a weekly online magazine and a virtual think tank, which aims to empower the voices of Iranian citizens, intellectuals and experts. Iran Press News frequently reports on human rights issues in Iran. Its English section is edited by Iranian human rights activist, Banafsheh Zand-Bonazzi, whose father was a political prisoner until his suicide, which was viewed as a form of protest against the government.

Political criticism
Opposition sites, pro-democracy sites and blogs expressing political criticism were found to be blocked in Iran over the last three years.

Opposition sites
Major opposition sites run by Iranians in exile were found to be blocked. These include the People’s Mojahedin Organization of Iran, a political-militant organization that advocates the violent overthrow of the Iranian government, as well as the sites of the Worker-Communist Party and the Labour Party (Toufan).

The Komala Party of Iranian Kurdistan is a left-wing Kurdish nationalist political party, founded by Kurdish university students in Tehran. Having engaged in armed struggle for the rights and freedom of the Kurdish people in the 80s and 90s, and having resumed armed struggle more recently, it is viewed by Iranian authorities as a terrorist organization, most likely explaining the motivation behind the blocking of its site.

Following the Iranian Revolution, the National Council of Resistance of Iran (NCRI) was formed in 1981 to act as a parliament in exile with 530 members, 52% of which are women, including representatives of ethnic and religious minorities. It aims to establish a secular democratic republic in Iran, based on the separation of religion and state. To this end, it has approved the National Peace Initiative of the National Council of Resistance of the Kurdish Autonomy Initiative, the Propagation of the Government Relations with Religion, and the Plan of Freedom and the Rights of Women, amongst other initiatives. We found the NCRI’s site to be blocked in Iran during the testing period.

Pro-democracy sites

We also found sites advocating for democracy in Iran and internationally to be blocked.
The National Democratic Institute (NDI) is a non-profit, non-partisan, non-governmental organization that has supported democratic institutions and practices around the world since 1983. As part of its work, NDI collaborates with local partners to promote citizen participation, strengthen civic and political organizations, and to safeguard elections. Iran is one of the many countries that NDI works in, having monitored elections and examined the roles of religious and political institutions. NDI’s site may have been blocked for being viewed as overly critical, and possibly for being perceived as interfering in internal affairs (through election monitoring, for example).
Similarly, we found the site of the National Endowment for Democracy (NED) to be blocked as well. Founded in 1983 by the United States Congress, NED is a non-profit foundation that also aims to create and strengthen democratic institutions around the world, including Iran. NED has supported projects in Iran that promote women’s rights, strengthen independent journalism, monitor human rights violations, and track parliamentary activities, amongst other projects.


Numerous blogs expressing political criticism were found to be blocked in Iran during the testing period.

These include the blogs of Iranian political activists, such as Ali Afshari and Ahmad Batebi. Ali Afshari campaigned for the democratic reform of Iran, publicly discussing human rights violations and advocating for freedom, human rights, and democracy. Having published more than 50 essays and having delivered more than 100 speeches on topics relating to democracy in Iran, he was imprisoned in 2000 and 2003, and spent 400 days in solitary confinement. Ali Afshari also carried out a research fellowship on “The Challenge of Democratization in Iran” with the National Endowment for Democracy (NED), whose site was found to be blocked, in addition to Ali’s site.

Ahmad Batebi, whose personal site was found to be blocked, was designated a “prisoner of conscience” by Amnesty International. He was involved in Iran’s student reform movement in the late 1990s when a fellow student activist was murdered right next to him by authorities. Once a picture of him holding the student’s shirt splattered in blood appeared on the cover of The Economist, he received a death sentence for “creating street unrest”. Following pressure from the international community, his sentence was commuted to a 15-year prison term, and eventually reduced to 10 years. While in prison, it was reported that he was subjected to torture. Ahmad Batebi eventually fled Iran and was granted asylum by the United States. He has since worked with the Voice of America (VOA) news agency, whose site was also found to be blocked in Iran.

Other blocked blogs include which writes about various sensitive topics, such as the Khordad movement, a political faction in Iran that aims to change the Iranian political system to include more freedom and democracy. We also found a similar domain, (possibly run by the same blogger, following the blocking of, to be blocked as well. The last post published on this domain (dated 24th September 2004) discusses the Pakdasht murders, a case involving the rape and murder of Afghan refugee children near Pakdasht. This suggests that the blog may have been blocked right after the last post was published, which questions the way that authorities handled the Pakdasht murder case. This finding is particularly interesting because it indicates that internet censorship in Iran may also be implemented as a means of hiding government responsibility.

Human rights issues

Numerous sites that discuss human rights violations and defend human rights were found to be blocked in Iran. These include sites specific to Iran, as well as international human rights sites.

Human rights sites focusing on Iran that were found to be blocked include the Center for Human Rights in Iran, Human Rights & Democracy for Iran, and Iran Human Rights, amongst others. The Center for Human Rights in Iran (CHRI) is an independent, nonpartisan, nonprofit organization headquartered in the U.S. that aims to protect and promote human rights in Iran. CHRI has been researching and documenting human rights violations in Iran since 2008, reaching around 1.5 million people inside Iran every month through social media. Similarly, Human Rights & Democracy for Iran is a Washington-based project of the Abdorrahman Boroumand Foundation, which “seeks to ensure that human rights in Iran are promoted and protected without discrimination”. As part of their research and reporting, they have published reports on the executions of political prisoners in 1988 and on Iran’s 2009 elections. Iran Human Rights is an Oslo-based non-profit organization that aims to create an abolitionist movement in Iran by increasing awareness about the death penalty. To this end, it has published a number of reports on executions in Iran.

Some international human rights sites found to be blocked include Human Rights Watch, the Human Rights Campaign, and Human Rights First. Over the last decades, Iranian authorities have exhibited limited tolerance when domestic issues are surfaced on the international agenda. The imprisonment of Ahmad Batebi, an Iranian activist who brought (more) international attention to human rights violations in Iran when he appeared on the cover of The Economist, is an example of this. Human Rights Watch has routinely been reporting on human rights violations in Iran, highlighting executions, torture, and the ill-treatment of minorities, and defending political prisoners and women’s rights. Therefore, the motivation behind the blocking of such sites might be attributed to their coverage of incidents that Iranian authorities may have incentive to conceal, and/or because they may be viewed as overly critical or inaccurate by authorities.

It’s worth emphasizing though that other major human rights sites – such as Amnesty International – which also report on human rights violations in Iran, were found to be accessible in Iran. The fact that Amnesty’s site was found to be accessible is particularly interesting because the organization has not been permitted to investigate human rights in Iran over the last decades.

Religious and ethnic minorities

According to international human rights organizations, such as Human Rights Watch and Amnesty International, religious and ethnic minorities in Iran have been victims of discrimination.
The Kurds are the third largest ethnic group in Iran. Amnesty has reported that while expression of Kurdish culture (such as dress and music) has generally been respected, the Kurdish minority in Iran continues to experience deep-rooted discrimination. Since 1918, there has been an ongoing separatist dispute between the Kurdish opposition in western Iran and the Iranian government. Kurdish ethnic rights defenders Farzad Kamangar, Ali Heydariyan and Farhad Vakili were sentenced to death in 2008, following what Amnesty called a “grossly flawed” judicial process. Many other Kurdish human rights defenders, community activists and journalists have faced arbitrary arrests and prosecution. Minority Rights Group International argues that the Kurds are amongst the communities at risk in Iran.

As part of this study, we found numerous Kurdish websites to be blocked. These include Kurdish news outlets, such as and, as well as Kurdish human rights sites, such as the Kurdish Human Rights Project. We also found the site of the Unrepresented Nations & People’s Organization to be blocked as well. Given the ongoing tension with the Kurdish separatist movement and the fact that such sites report on human rights violations against the Kurds, these censorship events may attempt to reinforce geopolitical dynamics of power.

Religious minorities have faced discrimination in Iran as well. Iran’s Baha’i population – the country’s largest religious minority – has systemically faced prosecution by authorities over the last century. Following the contested 2009 elections, Human Rights Watch argued that Iranian authorities targeted the Baha’i community as a cover for the post-election unrest. In late 2016, at least 85 Baha’is were imprisoned and allegations of torture surfaced for various other members of the Baha’i community. In addition to being persecuted for practising their faith, the minority has also been discriminated in terms of education, employment, and inheritance.

As part of this study, we found various Baha’i sites to be blocked. These include: The website of the worldwide Baha’i community The Baha’i faith Educational resources Baha’i online library Baha’i radio

Women’s rights

According to Human Rights Watch, women in Iran face discrimination in many aspects of their lives, such as marriage, divorce, and inheritance. Two years ago, authorities even sought to introduce discriminatory laws that would restrict the employment of women in certain sectors. Amnesty International has reported that Iranian authorities have targeted women human rights defenders, criminalizing initiatives related to feminism and women’s rights.
Our testing showed the blocking of various sites that defend and promote women’s rights. These include feminist sites (such as and, as well as AWID, an international feminist organization committed to achieving gender equality, sustainable development and women’s rights. We also found to be blocked, even though the domain is currently squatted.

LGBTQI rights
Both male and female homosexual activity is illegal in Iran under the country’s sodomy laws. Punishment for engaging in homosexual activity can result in multiple lashes and, in some cases, execution. Several years ago, it was reported that an 18-year-old was falsely charged of sodomy and sentenced to death. Earlier this year, Iranian police arrested more than 30 men on sodomy charges.

Iranian ISPs were found to be censoring sites connecting LGBTQI communities, as well as sites promoting LGBTQI rights. Grindr, an internationally popular social networking site geared towards gay and bisexual men, was amongst those found to be blocked. One of the first major sites for lesbians was also blocked. We found sites like ILGA, a worldwide federation campaigning for LGBTI rights since 1978, to be blocked as well.

While transexuality can be legal in Iran if accompanied by a gender confirmation surgery, transsexuals still experience social intolerance, similarly to many other countries around the world. This is also suggested by our findings, which show that sites on transsexuality were amongst those blocked in Iran.

Freedom of expression
Multiple sites promoting freedom of expression were found to be blocked in Iran. These include the Free Expression Network (FEN), an alliance of organizations dedicated to combating censorship and defending the right to free expression, as well as Free Speech TV, a U.S-based, independent news network committed to advancing progressive social change. We also found the site of the Committee to Project Journalists to be blocked as well.

Many sites run by international, non-profit, digital rights organizations were amongst those censored in Iran. These include:

Freedom House: An independent watchdog organization that conducts research and advocacy on democracy, political freedom, and human rights for most countries around the world (including Iran). It also monitors censorship, intimidation and violence against journalists, and public access to information. Both the HTTP and HTTPS versions of Freedom House’s site were found to be blocked.

Reporters Without Borders: An international non-profit, non-governmental organization headquartered in Paris that promotes and defends freedom of information and freedom of the press. Its mission includes combating censorship and laws aimed at restricting freedom of expression. Both the HTTP and HTTPS versions of Reporters Without Borders’ site were found to be blocked.

ARTICLE 19: An international non-profit, non-governmental organization defending freedom of expression. In collaboration with 90 partners worldwide, ARTICLE 19 carries out research and advocacy in support of free expression. Both the HTTP and HTTPS versions of ARTICLE 19’s site were found to be blocked.

ASL19: An independent technology group connected to both Iranians and technology actors in the West that aims to support civil society goals. To this end, ASL19 helps Iranians bypass internet censorship and more recently started providing support for circumvention tools in the broader Middle East and North Africa region. The HTTPS version of ASL19’s site was found to be blocked, but it remains unknown if the HTTP version is blocked as well because it hasn’t been tested (though the blocking of the HTTPS version strongly suggests that the HTTP version is likely blocked as well).

The Citizen Lab: An interdisciplinary laboratory based at the University of Toronto, focusing on research, development, and high-level strategic policy and legal engagement at the intersection of information and communication technologies, human rights, and global security. The Citizen Lab is known internationally for having published numerous research reports exposing internet censorship and targeted malware attacks against civil society members. Both the HTTP and HTTPS versions of The Citizen Lab’s site were found to be blocked.

Herdict: A project under Harvard’s Berkman Klein Center for Internet and Society which collects and disseminates real-time, crowdsourced information about internet filtering, denial of service attacks, and other blockages. Both the HTTP and HTTPS versions of Herdict’s site were found to be blocked.

Global Voices: An international community of writers, bloggers, and digital activists that translate and report on what is being said in citizen media worldwide. It started off as a project of Harvard’s Berkman Klein Center for Internet and Society and became an independent non-profit in 2008. Global Voices is known for its advocacy and reporting on digital rights issues, such as surveillance and internet censorship. The blocking of Global Voices appears to be limited to the HTTP version of the site. Our measurements show that while the HTTPS version of the site was accessible in Iran, block pages were served for the HTTP version.

Electronic Frontier Foundation (EFF): The leading non-profit organization defending civil liberties in the digital world. EFF champions user privacy, free expression, and innovation through impact litigation, policy analysis, grassroots activism, and technology development. Both the HTTP and HTTPS versions of the EFF’s site were found to be blocked.

The Centre for Democracy and Technology (CDT): An international non-profit organization that defends online civil liberties and human rights, driving policy outcomes to keep the internet open, innovative, and free. Both the HTTP and HTTPS versions of CDT’s site were found to be blocked.

Freedom of expression though also appears to be limited in Iran through the blocking of popular blogging platforms, such as,,, and

Communication Tools

Facebook Messenger was found to be blocked in Iran by means of DNS tampering. This was revealed by OONI’s Facebook Messenger test, which is designed to examine the reachability of the app by attempting to perform a TCP connection and DNS lookup to Facebook’s endpoints over the vantage point of the user. While the test was able to establish TCP connections to Facebook’s endpoints, DNS lookups to domains associated to Facebook did not resolve to IP addresses allocated to Facebook, illustrating that the app was blocked in Iran during the testing period.
Viber is another popular communications tool that we found to be blocked. While we didn’t measure the reachability of its app (we don’t have a test for that yet), we found its domain,, to be blocked across multiple networks in Iran. Quite similarly, we found PalTalk’s domain to also be blocked, as well as the domain of an Israeli mail provider.

Social Networks

Multiple social networking sites were found to be blocked in Iran over the last three years. Some of the most popular social networks internationally found to be blocked include:

But internet censorship in Iran is not limited to international social networking sites. We also found an Iranian social forum to be blocked as well. The censorship of this site, along with many others, cannot be disputed since the providers served blockpages.

The Telegram instant messaging service has more than 50 million users in Iran and 60% of the country’s Internet’s bandwidth is spent on using this app.

Following the Iranian government policy to censor every social network and instant messaging service in Iran, they have continued to disrupt access to Telegram. On Saturday, 19 May 2015, the telecommunication company of Iran blocked Telegram access in some parts of the Tehran province and some other provinces without prior notice.

Only one day after Telegram introduced the voice call feature in the messenger, the voice call functionality was completely blocked in Iran. Paul Durov wrote in response to users who had asked about voice calls problems in Iran: “Internet service providers in Iran have blocked it again.” The low cost of calling using this feature and the subsequent financial losses incurred by the telecommunication network operators, including the stated-owned Mobile Telecommunication Company of Iran, may have motivated the block, Although public relations of MTN Irancell announced that the operator has played no role in the disruption of the service.

Following the nationwide protests in Iran in 2017 and 2018, and to prevent rioting, the Supreme National Security Council of Iran decided to cut off all social networks, including Telegram, although it was said to be temporary. On the night of January 23, 2017, the block was lifted.

ifmat - Iran censor Telegram

An Iranian man demonstrates that he can’t use the messaging app Telegram in Tehran early January, which was temporarily blocked after anti-government protests erupted in Iran at the end of last year. (Abedin Taherkenareh/EPA-EFE)

On 20 October 2015, Pavel Durov, CEO of Telegram LLC said, after denying the request of Iranian authorities for private information about citizens of the country, Telegram was blocked for hours in Iran, but it was unblocked afterwards. Pavel Durov wrote an answer letter and announced that “Iranian authorities want to use Telegram to spy on their citizens. We can not help them in this regard.”

ifmat - Iran demanded telegram spying

Click here to see all news for Telegram in Iran

Media sharing platforms

Internet censorship in Iran also targets online platforms that share videos and images, amongst other forms of media. Some internationally popular media sharing platforms that were found to be blocked in Iran over the last three years include the following: | | | | |

In previous years, it was reported that ISPs in Iran applied “smart filters”, solely targeting specific pages in the HTTP version of Instagram, rather than blocking access to the whole site. However, our findings show that many ISPs in Iran are now targeting both the HTTP and HTTPS versions of such sites. Ever since sites like Instagram enabled HTTPS, Iranian ISPs appear to be carrying out a form of “blanket censorship” by blocking the HTTPS version as well, rending such sites completely inaccessible (since ISPs cannot limit their censorship to specific web pages when a site is hosted on HTTPS).


This study reveals and confirms censorship events in Iran through the analysis of thousands of network measurements that were collected from 60 local vantage points in Iran over the last three years. The network measurement data clearly shows how ISPs blocked sites and services and can therefore serve as evidence of information controls in Iran.

Our main conclusions from this study are summarized below.

1. The breadth and scale of internet censorship in Iran is pervasive. We found a wide range of different types of sites to be blocked (expanding beyond those that are illegal). Blocked domains include many news outlets and human rights sites, as well as blogging platforms, communication tools, online social networks, media sharing platforms, search engines, gaming sites, governmental sites, cultural and entertainment sites, amongst many other types of sites.

2. Iranian ISPs appear to be enforcing a type of “intranet” through censorship. By blocking access to popular international sites (such as,, and, Iranian ISPs appear to be creating a sort of “intranet” since non-censored internet activity appears to largely be limited to government-approved sites and services.

3. Internet censorship in Iran is quite sophisticated. (1) Iranian ISPs were found to serve block pages through DNS injection and through the use of HTTP transparent proxies. (2) We found ISPs to be blocking the same sites with different techniques (Aria Shatel, for example, served block pages for through DNS injection and HTTP transparent proxies). (3) ISPs were found to block both the HTTP and HTTPS versions of sites, making censorship circumvention harder. (4) Internet censorship is reinforced through the extensive blocking of popular censorship circumvention tools (which is not limited to domains, but expands to the blocking of the Tor network). (5) ISPs were found to *block online translators, possibly as an extra step to limit censorship circumvention.

4. Shift from “smart filters” to “blanket censorship”? A few years ago, when sites like Instagram did not support HTTPS, it was reported that Iranian ISPs only censored certain webpages, rather than blocking access to entire sites. Now, however, we are seeing that Iranian ISPs are also blocking the HTTPS version of sites, since it’s not possible to limit censorship to specific webpages when a site is hosted on HTTPS. This indicates that Iranian ISPs may have shifted their practices from applying “smart filters” (only censoring specific webpages) to a form of “blanket censorship” (censoring entire sites).

5. Internet censorship in Iran appears to be centralised. This is strongly suggested by the fact that we found consistency in terms of how internet censorship was implemented across networks. ISPs were not only found to be blocking the same sites, but they were also found to be using the same set of censorship techniques.

6. Internet censorship in Iran is non-deterministic. ISPs in Iran do not appear to block sites consistently across time. Rather, they were found to filp between blocking and unblocking sites, possibly in an attempt to create uncertainty on whether a site is actually censored or to make the censorship more subtle. Interestingly enough, ISPs were found to block some of the more popular sites (such as less frequently in comparison to less popular sites. This may suggest a political and/or social cost to censorship, which might be taken into account.

7. Political relations influence how information controls are implemented in Iran. This is strongly suggested by the fact that Iranian ISPs were found to block multiple Israeli and U.S. domains. Israeli domains even appear to be blocked almost indiscriminately. U.S. export laws, on the other hand, restrict the use of services (such as Norton, Virus Total, and Google App Engine) in Iran.

8. Internet censorship in Iran appears to reinforce geopolitical dynamics of power. Over the last century, there has been an ongoing separatist dispute between the Kurdish opposition in western Iran and the Iranian government. According to Amnesty International, many Kurdish human rights defenders, community activists and journalists have faced arbitrary arrests and prosecution. The blocking of numerous Kurdish sites, including news outlets and human rights sites, appears to be a politically motivated decision.

INVOLVED IN THIS ARTICLE: IRGC – Islamic Revolutionary Guard Corps;   Telecommunications Company of Iran (TCI)