Check how fast your internet really is. Find out if the problem is your WiFi or your internet line. Save every test in a log, and turn the log into a clear letter for your internet company.
🔒 Nothing about you is stored on our server. The test only sends empty test data. Your log stays in your own browser.
Your contract speed is in your contract, your invoice or the "Produktinformationsblatt". In Germany look for "maximal", "normalerweise" and "minimal".
One test uses up to about 300 MB on fast lines (less on mobile data: about 70 MB).
Do one test next to the router and one in the room where it is slow. If you can, also do one with a LAN cable. The tool compares them for you:
Saved only on this device. Test at different times: morning, afternoon and evening (19–23 h is peak time).
| Date & time | Type | Place | Down | Up | Ping | % contract |
|---|
Fill in your details. The letter uses the numbers from your log. You can edit everything before you send it.
This letter is a request to fix the problem. It is not legal proof. For a legal price cut or early cancellation in Germany you need the official measurement from the Bundesnetzagentur (see below).
It measures four things between your device and our server: ping (how fast your connection answers), jitter (how stable that answer is), download and upload speed. Then it compares the result with your contract, explains what you can do with that speed, and keeps a log.
Under § 57 Abs. 4 TKG you can pay less or cancel early if the speed is far below the contract again and again. The proof must come from the official tool at breitbandmessung.de:
Use this page first to find out quickly if the WiFi or the line is to blame. If it's the line, do the official measurement. Step by step: Internet slower than your contract? How to prove it. Free printable log: Internet speed log (PDF).
Every test uses a different server and method. Big apps often pick a server inside your provider's own network, which looks faster. Compare tests from the same tool over several days.
Walls, floors, distance and neighbours' networks weaken WiFi. Older phones and laptops also have slower WiFi chips. A cable gives you the true speed of your line.
On cable, getting 80–95% of your contract speed is normal. On WiFi in another room, 30–60% is common. If you get under 50% even on cable, contact your provider.
Yes. On mobile data the tool uses less (about 70 MB). Use WiFi if your data is limited.
No. The log is saved only in your browser. Clearing browser data deletes it, so download the CSV if you need it.
The letter asks your provider to fix the problem and records it. For a legal price cut in Germany you need the official Breitbandmessung protocol. This is not legal advice.