New OONI Probe Mobile App: Measure Internet Censorship & Performance

OONI mobile app

Today the Open Observatory of Network Interference (OONI) project is thrilled to announce the release of a new mobile app (“OONI Probe - Measure Internet Censorship & Performance”) that can now be installed on Android and iOS for testing Internet censorship and network performance.

By running the tests included in OONI’s mobile app, you can monitor:

The results of your tests will be published, increasing transparency of internet censorship and network interference around the world.

Collecting evidence of internet censorship

OONI’s Web Connectivity test is designed to examine whether websites are blocked and if so, how. This test, in particular, attempts to determine whether access to sites is blocked through DNS tampering, TCP/IP blocking, or by a transparent HTTP proxy. By knowing how access to sites is interfered with, you can more easily evaluate how to circumvent that specific type of censorship. As OONI is committed to transparency through the publication of all network measurement data, you can use it as evidence of any censorship events that you come across.

Detecting systems responsible for censorship and surveillance

Various types of proxy technologies are used in networks for implementing censorship, surveillance, and traffic manipulation. OONI’s HTTP invalid request line test is designed to uncover the presence of such systems within tested networks. However, it’s important to point out that not all systems that you might find are necessarily responsible for censorship and/or surveillance! Many proxy technologies, for example, are used in networks for caching purposes.

Measuring the speed and performance of your network

Sometimes the network that we are using doesn’t work as well as we’d like it to. OONI’s implementation of the Network Diagnostic Test (NDT) attempts to measure the speed of your network by connecting to M-Lab servers near you and by subsequently uploading and downloading random data. In doing so, NDT collects low level TCP/IP information that can help characterize the speed and performance of your network. Such information can also be useful in examining cases of throttling.

Open data

OONI publishes all network measurement data that it collects and processes because open data allows third parties to conduct independent studies, to verify OONI findings and/or to answer other research questions. Such data also helps increase transparency around internet censorship and various forms of network interference. All data is published on OONI Explorer.

Once you have run each test, you should be able to view the results of your tests directly in the app, as illustrated below:

Test results

Free software

All OONI tests, as well as its NDT implementation, are based on free and open source software (the network measurement library MeasurementKit). You can find the source code through the following links:

Next steps

More tests will be integrated into OONI’s mobile app within the next year, including - but not limited to - our new WhatsApp and Facebook Messenger tests. In the meanwhile, learn about potential risks associated to running OONI Probe. If you feel comfortable with them, install OONI’s mobile app and test every network you connect to!


The OONI team thanks the Open Technology Fund for sponsoring the development of OONI’s mobile app, and M-Lab for sponsoring the development of Measurement-Kit at the Nexa Center for Internet & Society.