NDT Speed Test

NDT (Network Diagnostic Test) is designed to measure the speed and performance of tested networks.

This network performance test was originally developed by The Internet2 Project and is currently maintained by Measurement Lab (M-Lab). NDT is designed to measure the speed and performance of networks by connecting to M-Lab servers close to the user, and by subsequently uploading and downloading random data. In doing so, NDT collects TCP/IP low level information that is useful to examining and characterizing the quality of the network path between the user and the mLab server.

OONI utilizes an implementation of NDT for measurement-kit, which is a network measurement library for running both desktop and mobile network measurement tests. Running NDT can be useful as the type of information that it collects can potentially be used to examine cases of throttling.

Disclaimer: NDT is a general-purpose performance test conducted against third-party servers provided by Measurement Lab (M-Lab). M-Lab’s NDT services require the retention and disclosure of IP addresses for research purposes. Learn more about M-Lab’s data governance, see its privacy statement.

Read the NDT test specification.