Speed tests are useful, but the number on the screen is not a permanent label for your internet connection. A browser-based speed test measures performance between your device, browser, local network, internet provider, and the test endpoint at that moment. Wi-Fi quality, device load, routing, congestion, and server distance can all affect the result.

How to test

Run one test on Wi-Fi, one near the router, and one on a wired connection if possible. Close large downloads, cloud backups, video calls, and streaming apps. Repeat the test at different times of day. If results vary heavily, the issue may be congestion or Wi-Fi quality rather than your plan speed.

How to interpret the result

Download speed affects streaming, browsing, and large file downloads. Upload speed matters for video calls, backups, and sending files. Ping measures round-trip latency, which affects responsiveness. Jitter shows how stable latency is; high jitter can make calls and games feel unreliable even when download speed looks fine.

Limitations

A speed test does not measure every website. WhatsMyDevice uses Cloudflare endpoints, which are useful for real-world web performance, but your route to a game server, workplace VPN, or streaming provider can differ. Browser overhead and device power-saving modes can also affect results.

What you can do

Test wired and wireless separately, restart overloaded network equipment, check whether other devices are using bandwidth, and compare peak hours with quiet hours. Share repeated results with your ISP if you need support.

FAQ

Why is my speed lower on Wi-Fi? Signal strength, interference, and router limits often reduce Wi-Fi speed.

Is ping more important than download? For calls and games, often yes.

Why do tests differ by site? They use different endpoints, routes, and measurement methods.