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Open Observatory of Network Interference

A free software, global observation network for detecting censorship, surveillance and traffic manipulation on the internet

OONI Explorer

OONI has been monitoring internet censorship around the world since 2012

Explore OONI Data

What OONI does

OONI develops free software tests designed to examine the following:

  • Blocking of websites
  • Blocking of instant messaging apps
  • Blocking of Tor and other circumvention tools
  • Detection of systems that could be responsible for censorship and/or surveillance

    Testing methodology

    There are risks. Running a probe involves testing connections to websites that may be banned and using tools to attempt circumventing web censorship. It is not designed to protect the privacy of those running probes. Measurements are published and can include IP addresses or other identifying information.

    More about the risks

How OONI Works

OONI scans TCP, DNS, HTTP and TLS connections for tampering. Some tests work by requesting data over an unencrypted connection and comparing against a known good value. Others check for DNS spoofing, keyword filtering, transparent proxying and website block lists.

Getting Involved

Join us in IRC #ooni on OFTC (or via a slack bridge) or on the ooni-talk and ooni-dev mailing lists to discuss the project, what you've learned from measurements and ways you can help out.

If you are contributing regular ooniprobe measurements be sure to also subscribe to ooni-operators for important updates.

Source code is available (Tor project mirror). Issues and future plans for OONI can be found on github.


To contact the OONI team send an email to Encrypted emails can be sent using the following PGP key:

Key ID: 6B2943F00CB177B7
Fingerprint: 4C15 DDA9 96C6 C0CF 48BD 3309 6B29 43F0 0CB1 77B7