Make firefox desktop client look like smartphone client when accessing website

Question

I am testing a website that only works for smartphones but currently I am stuck with a desktop client of firefox.

I know I can tell firefox to behave as a smartphone client, but I have no idea how to do it.

I have tried searching in Google, but the results were not statisfactory, probably becuase I do not know the "exact question" that doing this requires.

Can someone help me?

Answer 1

Try something like User Agent Switcher?

https://addons.mozilla.org/en-US/firefox/addon/user-agent-switcher/