Internet too slow? Test your speed and enforce your rights (2026)
Measure correctly, use the official measurement tool and, if the line is consistently too slow, reduce payment or cancel — how to enforce your rights.
“Up to” is not everything — you have a claim
Providers advertise “up to” speeds, but that is not the end of the story. The contract and the product information sheet must state the minimum, the normally available and the maximum speed.
These values are binding. If your line consistently delivers much less, that is so-called underperformance — and then you have concrete rights.
The first step is therefore to measure your actual value cleanly and compare it with the agreed values in the product information sheet.
How to measure correctly
A single app measurement is not enough. Connect your computer to the router via a LAN cable, not Wi-Fi — Wi-Fi distorts the result and is not part of the provider’s promise.
Close other devices and running downloads so the measurement is not skewed by parallel traffic. Measure several times and at different times of day.
Note download, upload and date of each measurement. This documentation is the basis if you later want to make a claim.
The official measurement tool of the regulator
For legally robust evidence there is the official measurement tool of the Federal Network Agency (the “Breitbandmessung”). It guides you through a standardised measurement campaign over several days.
You measure several runs on two days. If the result meets the legal criteria for underperformance, the tool creates an official measurement protocol.
This protocol is your strongest evidence towards the provider — far more meaningful than single speed tests from the internet.
Your rights with a consistently too slow line
If there is a proven significant, continuous deviation from the agreed values, you may reduce the monthly fee — in proportion to how much the actual performance deviates from the agreed one.
Alternatively you have an extraordinary right to terminate: you can end the contract even if the minimum term is still running, without being stuck on a slow line.
First contact the provider in writing, attach the measurement protocol and set a deadline to fix it. If performance still fails, assert a reduction or termination.
When switching is the better solution
Sometimes the cause is the connection type itself — e.g. slow DSL where cable or fibre is now available. Then switching plans achieves more than any complaint.
Check availability for your exact address. If a faster connection type is available, a switch can fundamentally improve speed.
Use an extraordinary right to terminate for underperformance as a chance to move to a better and often cheaper plan.
Practical tips
- Measure via a LAN cable directly at the router, not over Wi-Fi.
- Close other devices and downloads during the measurement.
- Use the regulator’s official measurement tool for a robust protocol.
- Compare your result with the values in the product information sheet.
- Complain in writing with a deadline and attach the protocol.
Common mistakes to avoid
- Measuring only over Wi-Fi and wondering about low values.
- Treating a single measurement as proof.
- Streaming or downloading in parallel during the measurement.
- Ignoring the official tool and using only online speed tests.
- Never checking the agreed minimum values in the product information sheet.
Checklist before you compare
- Agreed min/normal/max values found in the product information sheet.
- Measured via LAN cable several times and at different times.
- Official measurement protocol of the regulator created.
- Deviation documented and compared with the contract.
- Provider contacted in writing with a deadline.
- Reduction, termination or switch considered.
Frequently asked questions
How do I know if my internet is too slow?
Compare your measured speed with the agreed values in the product information sheet. A significant, lasting deviation is underperformance.
How do I measure my speed correctly?
Via a LAN cable directly at the router, with no other active devices, several times and at different times of day.
What is the regulator’s measurement tool?
An official tool that measures in a standardised way over several days and creates a legally robust protocol in case of underperformance.
What rights do I have with a too slow line?
You can reduce the monthly fee or terminate the contract extraordinarily — depending on the extent of the deviation.
Is switching better than complaining?
If the cause is the connection type and faster cable or fibre is available, switching often achieves more than a complaint.
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