On an Android smartphone or tablet? Use the Ookla Speedtest application.
For best results, use this recommended Silver Star speed test. Using other speed test sites off the Silver Star network may not result in an optimal reading. For the most accurate results, use an Ethernet cable to connect your laptop or computer directly to your router/gateway. Shut down all other programs and applications apart from the test. Testing speeds using a wireless device, especially with multiple devices connected to your network, is going to render the result inaccurate.