I don't think this is true anymore. This website used to give a disclaimer to firefox users and does not anymore :
This is the website I like to use. Will give pianoboi a try though.
That site says it's still Chrome only. On Firefox I get this: (maybe it's mobile Firefox)
> If you are reading this it means that your browser does not support the WebMIDI extension.
> This is a real pity, but with some luck Google Chrome will work on your system.
> If you already have chrome please start up chrome and revisit the website using that browser, otherwise you will have to install it.
> For FireFox this has been an open issue for Eight Years. See: this bugzilla entry.
> That's annoying because FireFox is normally my daily driver but eight years is enough to have to wait for a feature like that.
> So, I'm really sorry, but please switch to Chrome for this project, until Mozilla gets its act together, assuming it ever will.
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There's really no such thing as web standards anymore. Google just does whatever it wants and sometimes the other browsers work, and sometimes not...
It's the disclaimer I was talking about
Yes it's because you're on mobile Firefox