Chromium, the skeletal open-source browser at the core of Chrome, Opera, Vivaldi, Brave and a few other browsers will receive support for the automatic playback of MP3 files. Until now, Chromium has supported various audio formats such as OGG, FLAC, Opus, WAV, PCM, and others. The decision to add MP3 support to Chromium comes after the company behind the audio codec terminated its MP3 commercial licensing program, leaving the MP3 standard in the public domain.
Source: https://www.bleepingcomputer.com/news/software/chromium-to-get-mp3-support-after-mp3-becomes-patent-free/