Internet, Browser & System Tests

Test your internet connection

Start with the internet speed test. In about 25 seconds it measures download and upload speed in Mbps, ping and jitter, and how much your ping rises when the line is full (the bufferbloat grade), then says what the connection is good for. If games or calls lag but the speed looks fine, run the ping test for 30 or 60 seconds: it draws every reading so you can see spikes and lost requests, and gives a verdict for gaming and video calls.

For a fair result, test once over a network cable or next to the router. If the cable result is close to your plan and Wi-Fi is much slower, the problem is the Wi-Fi, not the line.

IP address, DNS and VPN checks

What is my IP shows your public IPv4 and IPv6 addresses, the provider that owns them, the rough location websites see and a hint when it looks like a VPN or proxy. The WebRTC leak test checks whether your browser reveals your real IP through WebRTC while a VPN is on. The DNS lookup reads A, AAAA, MX, TXT, NS and other records for any domain, compares Cloudflare and Google to see whether a change has spread, and times eight public DNS servers to find the fastest one for you.

Browser, graphics and device details

What is my browser names your browser and version, checks whether it is up to date and lists 47 web features it does or does not support. The user agent page shows the exact string your browser sends, with a parser for any other one. The WebGL test checks WebGL and WebGPU, names your graphics card, warns when hardware acceleration is off and runs a short GPU benchmark. Device info puts the operating system, screen, CPU threads, memory, GPU, network and battery on one page with a copy button, and screen resolution shows the real pixel count and scaling. On a phone, what phone do I have finds the model.

Fixing a slow or laggy connection

• Slow everywhere: restart the modem and router, then test over a cable. If the cable result is far below your plan at several times of day, contact your provider with the results.
• Slow only on Wi-Fi: move closer to the router, use the 5 GHz or 6 GHz band, or add a mesh point. Walls and distance are the usual cause.
• Lag when others use the internet: a poor bufferbloat grade. Turn on SQM or QoS in the router.
• Sites slow to start loading: try a faster DNS server from the DNS speed test.
• 3D sites and browser games stutter: check the WebGL test says hardware acceleration is on.

Privacy

The tests run in your browser. The speed and ping tests exchange random data with Cloudflare's nearest data centre, the IP tools ask Cloudflare, ipify and the internet registries what address your connection uses, and DNS lookups go to Cloudflare or Google over HTTPS. These services see your IP address, as every website you visit does. Testnook does not receive or store any of the results; your speed test history stays in your own browser.