Convert between MP3, WAV, FLAC, AAC, M4A, OGG, WMA, OPUS.
You can convert in either direction between MP3, WAV, FLAC, AAC, M4A, OGG, WMA, and OPUS. You can also upload AIFF as a source format (it can't be chosen as a target).
Yes, there's a limit of 100 MB and 60 minutes per file.
For conversions to lossy formats (MP3/AAC/OGG/WMA/OPUS), it sets the bitrate — lower gives a smaller file, higher gives better audio quality. Since WAV and FLAC are lossless, this setting doesn't appear for them.
Yes, the 'Advanced settings' section lets you trim a section, adjust volume (-20/+20 dB), and change playback speed (0.5x-2x).