So far, it appears that most speed tests run with Speedtest Custom variants use IPv4.
That doesn't surprise us, in 2024 we concluded IPv6 is not faster than IPv4.
However, it should be possible to test based on IPv6. Ookla requires that test servers have (...) IPv4 and IPv6 functionality (for all servers in countries where IPv6 usage is higher than 30%) (...)
Testing over IPv6 is rare
We know of only one clone that allows IPv6 based testing, namely MySpeedMeter (see also Measuring IPv6 internet speed with Ookla).
Two things stand out in the URLs used by MySpeedMeter:
- The subdomain dualstack is used: hktp6.dualstack.speedtestcustom.com/?serverId=12370/
- The ServerId of the test server is mentioned in a query parameter: hktp6.dualstack.speedtestcustom.com/?serverId=12370/
For testing via IPv6, the subdomain dualstack is required. The ServerId is required to indicate which test server is used.
Force testing over IPv4
Although it seems that most Speedtest speed tests are performed based on IPv4. It seems to be possible to enforce this. You can do this by adding the subdomain ipv4-only as follows:
[customer].ipv4-only.speedtestcustom.com
Our sample speed test URL now becomes: https://speedtpe.ipv4-only.speedtestcustom.com/