OONI Probe turns your device into an internet censorship sensor

OONI Probe is a free tool for Linux and macOS that tests whether websites and messaging apps are being blocked on your network. Beyond simple reachability checks, it can verify whether services like WhatsApp, Facebook Messenger, and Telegram are accessible, confirm whether circumvention tools function, and benchmark network speed and performance using the NDT test built with M-Lab.

Every run automatically publishes results in near real-time to a public repository, feeding what OONI describes as the world’s largest open dataset on internet censorship. The value is aggregate: individual measurements from volunteers across many countries combine into a global, continuously updated picture of where and how the internet is being filtered.

For technical readers, the appeal is that participation is low-effort and the data is open — researchers, journalists, and policymakers can query measurements from anywhere in the world to document network interference and hold censors accountable.