How can I test the speed of my internet connection?

To perform a speed test, proceed as follows:

  1. Disconnect your router from the power supply for five minutes before the speed test
  2. Disconnect all devices from the router and use the Ethernet cable to connect your computer/laptop directly to the router (PLEASE NOTE: WLAN speed tests are not permissible for measurements)
  3. Restart your computer/laptop and open a browser (Chrome or Firefox)
  4. Call up the Init7 speed test server
  5. Carry out two to three measurements

If the speed values are still unsatisfactory even after these factors have been taken into consideration, contact our Fiber7 support team.

Please include three links of the speed test results (example) along with your enquiry as well as a list of the hardware you are using (from the end device to the OTO socket) so that we can carry out our troubleshooting with precision.


Fiber7, Fiber7-X and Fiber7-X2 has a nominal speed of respectively 1, 10 and 25 Gbit/s (gigabits per second). This does not necessarily mean 1000, 10000 and 25000 Mbit/sec (megabits per second), however. Under ideal conditions, the maximum possible speed is 940, 9400 and 23500 Mbit/sec (the Ethernet throughput limit).

Countless factors can negatively affect speed. Experience has shown that 99% of all complaints are due to problematic configurations or the customer’s own applications. Before you contact our support team, please note the following:

WLAN speed tests cannot be accepted. Valid speed tests must be performed with an 8-pin Ethernet cable (at least Cat 5E). sometimes suggests unfavourable test servers. Please use only our speed test server (Speedtest-Server).

The firewall activated by default in Windows 10 causes massive slowing. Please disable the firewall before performing the speed test (the same applies to older versions of Windows).

Apple Macbooks made in 2014 or before are unable to reach the nominal speed even when using a gigabit interface. For this reason, please use current hardware to perform the test.

The CPUs in many common routers are too weak to deliver gigabit-level performance. In addition, firewalls from Zyxel (older than 2016) and many other manufacturers have inadequate specifications and are often able to deliver speeds of only a few hundred Mbit/sec.

Some web browsers can cause problems when combined with certain operating systems. For example, the speed is shown as being too low with Safari on Apple, but with Firefox on Apple the technically possible speed is able to be achieved. So please always perform the test with at least two different web browsers.

Iperf3 offers an alternative possibility for a speed test:

$ sudo apt-get install iperf3
$ iperf3 -c

iperf3 can be extended by further parameters. -4 resp. -6 specifies whether the test is performed via IPv4 resp. IPv6. -R reverses the test direction. Further options via iperf3 --help