Based on multiple speed test tests, these are the factors that can affect your speed test results:
Your home network (Unpredictable)
Your home network capacity can easily have the biggest impact on test results.
If you see extreme differences in the test results, and they are improbably low, then your home network is probably the culprit.
Google Fiber has a nice overview of the maximum speed that can be expected based on the hardware used.
For more information see the second ultimate home network test 2022.
Tip: Use the option "I suspect my home network is the bottleneck" of the Interactive Speed Test Advisor to be sure.
Large downloads (>70% slower)
Large downloads have a big impact on your test results.
Using TOR (>60% slower)
Due to the use of the Onion services used by the TOR browser, your internet speed is significant slower when you use the TOR browser.
No significant impact
- Browser used
- Other active programs
- Test server used
- DNS server used
- IP protocol used
- Video streaming
Hard to test
For the following factors it is not clear how they influence your speed test results. It depends on your configuration:
- The VPN you use
- The computer quality/operating system
- Router location
- Time of the day