test my wi-fi speed

Does your WAN network consist of Access Points? Inclusion of Access Points or Wi+Fi extenders etc will see Total capacity distributed / divided accordingly. There are other factors as well including hardware limitations within your devices (if any).

Note that I am assuming here that you are talking about your internal home network and not your outside Internet connection speed. If you are talking about your outside internet connections speed then that too can be affected by speed limitation in certain arrangements. Talk to your Internet Service Provider in this case.

Axel F.

Sounds like something you need to talk to your ISP about.