Censorship checkers
OONI Probe is a free and open-source censorship checker that runs all kinds of tests to detect and document internet blocking.
These tests identify if websites, instant messaging apps (like WhatsApp, Telegram), and internet circumvention tools (such as Tor) are being blocked. The tools also detect the presence of middleboxes, which are network devices capable of manipulating or monitoring internet traffic.
All collected measurements are published as open data on OONI Explorer. This publicly available dataset provides a real-time global picture of internet censorship. It allows researchers, journalists, and human rights defenders to track emergent censorship events and analyze trends over time.
OONI also analyzes this data, often in collaboration with local partners, to identify patterns in internet censorship. They publish research reports to shed light on specific blocking incidents. This work provides concrete evidence of internet interference and supports efforts to advocate for internet freedom worldwide.
A censorship checkers that focuses on China is Blocky (uses AI to monitor censorship and expand free speech).