Why HTML `<input type=“file” />` accept property `audio/mpeg` and `audio/mp3` works the same if I just want to select MP3?

Question

Please see these two minimum examples

audio/mpeg

 <input type="file" accept="audio/mpeg">

 <input type="file" accept="audio/mp3">

Both examples can select the only MP3, why is this happening?

If I want to force my user to just select an MP3 file, which code snippet should I use?

Which one is the best?

Answer 1

An MP3 is just the audio portion of a MPEG file, so specifying audio/mpeg is equivalent to specifying audio/mp3 .

More info about media formats can be found in this article on MDN.