Varying results on speed tests

I apologise now if this is in the wrong place but it is a general question.

I tend to use ookla speedtest to check my speeds, which are ok but not the best. However, can someone explain why I get a difference in results between using the online test and the windows app, ebven when doing them seconds apart I can get results that are poles apart (upto 16 ish Mdps). the slower speeds always come from the App.

Any info appreciated

Paul

One of the problems is which server they use one can use a server 10 miles away and the other 200 miles away even speed test can vary the server.

Samuria said:

One of the problems is which server they use one can use a server 10 miles away and the other 200 miles away even speed test can vary the server.

I understand that but I have done the speed tests making sure to set them to use the same server. I just wondered if one was more accurate than the other.

Using the same server test results may vary depending on:

hardware used
available bandwidth
network congestion
unexpected use of bandwidth while testing (software on testing computer or other tablets/computers on the network)
use of VPN
not rebooting before testing (router and computer)
not using the same browser and/or not clearing cache
etc.

see these links:
Speedtest Frequently Asked Questions
Speedtest Help
How to Test Your Wi-Fi Speed (And 7 Mistakes You Should Avoid)
5 Rules for a More Accurate Internet Speed Test

Such speed measurements are not accurate they give you a rough idea. Even if it is the same server the route can vary, the congestion will vary on that route, load on the server, and thus the speed.
Anything else will not be using that server anyway.