FAQ
M-Lab Frequently Asked Questions
For in-depth documentation on how M-Lab works, visit the M-Lab Knowledge Base →
About M-Lab
What is M-Lab?
Measurement Lab (M-Lab) is the largest open source Internet measurement effort in the world. M-Lab provides publicly available speed tests and network diagnostics, collects the resulting data, and publishes it openly for researchers, policymakers, and the public.
→ Welcome to M-Lab: Open Internet Measurement
Who runs M-Lab?
M-Lab is an open source project with contributors from civil society organizations, educational institutions, and private companies. It is a fiscally sponsored project of Code for Science & Society. M-Lab's infrastructure and operations are supported by academic institutions, private foundations, and private companies.
How can I contact M-Lab?
Email support@measurementlab.net or join the M-Lab Discuss group.
Tests
What measurement tests can I run?
The most commonly used test is NDT (Network Diagnostic Tool), which measures download speed, upload speed, latency, and packet loss. M-Lab also hosts MSAK (a configurable multi-stream test), WeHe (traffic differentiation detection), DASH (video streaming emulation), and Reverse Traceroute.
→ NDT — Network Diagnostic Tool
→ MSAK — Measurement Swiss-Army Knife
→ WeHe — Traffic Differentiation Detection
→ Neubot DASH Streaming Test
Why are my M-Lab results different from other speed tests?
Three factors drive differences between tests: (1) M-Lab always tests off-net — traffic crosses your ISP's network border, where congestion is most likely to occur; (2) NDT uses a single TCP stream, which is more sensitive to network problems than multi-stream tests; (3) Internet routing changes constantly, so results from different moments in time reflect different conditions.
→ Understanding Speed Test Results
Will these tests monitor my private Internet activity?
No. M-Lab tests measure only synthetic traffic between your device and an M-Lab server. Your browsing history, email, and other private traffic are never collected. See our Privacy Policy and Acceptable Use Policy for details.
How do I report issues with M-Lab tests?
Most tests complete in under 30 seconds. If a test hangs or fails, try again, try from a different network, and check whether a firewall is blocking the connection. If the problem persists, email support@measurementlab.net with your OS, browser, test name, and any error messages.
Data & Privacy
What data is collected when I run a test?
Tests collect network performance measurements (speed, latency, packet loss), the IP address assigned to your device by your ISP, and basic metadata such as browser version. No personally identifiable information beyond the IP address is collected. All data is published publicly under a CC0 1.0 license and stored indefinitely to support longitudinal research.
→ M-Lab Network Annotations: Geolocation, ASNs, and What They Mean
→ Privacy Policy
Where is data stored and how can I access it?
Raw test data is stored in Google Cloud Storage, and NDT data is also queryable via Google BigQuery at no charge to users.
→ Getting Started with M-Lab Data in BigQuery
→ Accessing M-Lab Data Buckets
How precise is the location information in M-Lab data?
M-Lab annotates tests with geographic information derived from IP address geolocation, which is accurate to approximately the city or county level — not street address or GPS precision. Third-party integrations of M-Lab tests may collect more precise location data independently.
→ M-Lab Network Annotations: Geolocation, ASNs, and What They Mean
Can my test data be deleted or anonymized?
M-Lab collects only your IP address as potentially personal data. Users in the EU, California, and other jurisdictions with applicable privacy regulations may request deletion or anonymization. To exercise these rights, you will need to provide the IP address assigned to you at the time of the test.
→ Privacy Policy — GDPR and Data Rights
Getting Involved
How can individuals support M-Lab?
Run tests regularly — you gain insight into your connection, and the public benefits from the data. Developers and data analysts can also work with M-Lab's open source tests and datasets.
How can researchers use M-Lab?
M-Lab provides open access to billions of measurements via BigQuery and Cloud Storage. Join the M-Lab Discuss group and explore the resources below to get started.
→ Getting Started: Researchers
→ Analyzing M-Lab Data: A Researcher's Guide
→ Getting Started with BigQuery
How can ISPs, IXPs, or other organizations get involved?
Organizations can contribute by hosting M-Lab measurement nodes, providing network connectivity, or offering financial support. ISPs and IXPs can sponsor servers in their region or integrate M-Lab tests into their own products.
→ Getting Started: ISP and IXP Staff
→ Running Your Own M-Lab Node: The BYOS Program
→ Contribute to M-Lab
How can I add an M-Lab test to my website or app?
M-Lab's NDT test is open source and has been integrated by Google Search, Fing, and many others. Review the developer guide or contact support@measurementlab.net to get started.
→ Integrating M-Lab Tests Into Your Website or App → Developer Guide
Can I host my own experiment on M-Lab?
M-Lab accepts applications from researchers who develop open source network measurement tests, but the bar is high: accepted tests must align with M-Lab's mission, not duplicate existing tests, and have sustainable long-term funding. Read M-Lab's procedures for new tools before reaching out to the operations team.
Have a question not answered here? Email support@measurementlab.net
Supporters
