Stiftung Warentest analysed the data from the "big four" - 1&1, O2, Telekom and Vodafone - as well as six regional providers. More than 300,000 measurements carried out via the Federal Network Agency's app were analysed.
In many measurements, the advertised maximum performance is not achieved and no provider reliably delivers three quarters of the maximum performance. Project manager Thomas Grund comments: "The detailed analysis shows considerable differences between the providers and also between urban and rural areas. The values are slightly better in large cities than in rural areas."
Customers do not have to put up with lower speeds. According to Stiftung Warentest, they are entitled to a price reduction or contract cancellation if the promised speed is not achieved. Multiple measurements with a LAN cable provide a legally secure measurement protocol. The Federal Network Agency's app is available at breitbandmessung.de .
The data was analysed by the specialist service provider zafaco, which also developed the Desktop-App and provides technical support. zafaco and the Federal Network Agency offer validated measurement results in the form of maps online on a daily basis. The map view in the browser allows filtering by region, provider and bandwidth class.
Stiftung Warentest has prepared the data provided in the form of tables and graphics. They are available in the April issue of the magazine test and at www.test.de/schnellesinternet .