Are websites or social media apps blocked on your network? Is your internet connection slower than usual? OONI Probe is a free, open-source app designed to help you find out if your network is subject to censorship, surveillance, or performance issues.
About OONI
Developed by the Open Observatory of Network Interference (OONI) under The Tor Project, OONI Probe empowers users worldwide to detect internet restrictions and collect evidence of network interference. Since 2012, OONI’s global community has gathered millions of network measurements across more than 200 countries, providing vital data that exposes internet censorship and interference worldwide. By running tests with OONI Probe, you can contribute to this global effort and better understand the state of your own internet connection.
Detect Website and Social Media Blocking
OONI Probe helps you check whether popular websites and instant messaging apps are being blocked on your network. By running targeted tests, the app reveals if specific online services are restricted, helping you identify censorship practices affecting your access to information.
Identify Censorship and Surveillance Systems
The app tests for the presence of middleboxes—network devices that can censor or surveil your internet traffic. These systems might manipulate or filter content, and OONI Probe can detect their activity on your network, uncovering attempts to control or monitor your online experience.
Measure Network Speed and Video Streaming Quality
OONI Probe includes tests for network performance such as the Network Diagnostic Test (NDT), which measures your connection’s speed and reliability. Additionally, the Dynamic Adaptive Streaming over HTTP (DASH) test evaluates how well your network handles video streaming, so you can pinpoint slowdowns or disruptions.
Open Data for Transparency and Research
All data collected by OONI Probe users is published openly online. This transparency allows researchers, journalists, and activists to verify findings, conduct independent analyses, and better understand global internet censorship patterns. Explore and download the data at ooni.io/data.
Free and Open Source Software
OONI Probe and its network tests are completely free and open source, developed openly on GitHub. This commitment to open software ensures transparency, security, and community collaboration. Learn more about how the tests work at ooni.io/nettest.
Stay Connected
Follow OONI on Twitter @OpenObservatory to receive updates and learn more about global efforts to fight internet censorship and promote digital rights.
FAQs
1. What does OONI Probe test for?
OONI Probe tests if websites and messaging apps are blocked, detects censorship and surveillance systems, and measures your network’s speed and video streaming performance.
2. Is OONI Probe free and safe to use?
Yes! OONI Probe is completely free, open-source software developed with privacy and transparency in mind.
3. How does OONI Probe help uncover internet censorship?
By running network tests, OONI Probe collects data on blocked websites and network interference, which can be used as evidence of censorship worldwide.
4. Can I view the data collected by OONI Probe?
Absolutely. All network measurement data is openly published at ooni.io/data for public access and research.
5. Who develops OONI Probe?
OONI Probe is developed by the Open Observatory of Network Interference (OONI), a free software project under The Tor Project focused on revealing internet censorship globally.
Version History
v5.0.6—30 Apr, 2025
Minor bug fixes and improvements. Install or update to the newest version to check it out!
v5.0.5—25 Mar, 2025
Minor bug fixes and improvements. Install or update to the newest version to check it out!
v5.0.3—25 Feb, 2025
* Measurement engine synced with OONI Probe CLI v3.24.0.
* Major UI improvements.
* Bug fixes and improvements.
