Compress MP3
Upload an audio file (MP3, WAV, AAC, OGG, M4A, FLAC) and re-encode it as an MP3 at your chosen bitrate. Lower bitrates produce smaller files at the cost of audio quality — 64 kbps is voice-memo grade, 128 kbps is standard for podcasts and casual listening, and 256 kbps is high quality for music.
This is useful for shrinking audio files before emailing, uploading to platforms with size limits, or batch-compressing a library of recordings that don't need studio quality. The tool also serves as a simple audio format converter — drop in a WAV or FLAC and get back an MP3.
Everything runs in your browser using ffmpeg.wasm — your audio file is never uploaded to a server.
By The Paper Room Editorial Team — Audio Tools
Frequently asked questions
What bitrate should I choose?▼
64 kbps is suitable for voice recordings and spoken content where small size matters more than fidelity. 96 kbps is acceptable for podcasts. 128 kbps is the standard for casual music listening. 192 kbps is good quality, and 256 kbps is high quality where most listeners can't tell the difference from the original.
Can I use this to convert WAV or FLAC to MP3?▼
Yes — the tool accepts WAV, FLAC, AAC, OGG, and M4A files in addition to MP3. It re-encodes everything as MP3 at your chosen bitrate, so it doubles as a simple format converter.
Will this make my MP3 smaller?▼
Only if you choose a lower bitrate than the original. Re-encoding a 128 kbps MP3 at 128 kbps won't meaningfully reduce the file size. To shrink an MP3, pick a bitrate lower than the source — for example, re-encoding a 320 kbps file at 128 kbps will roughly halve the size.
Does this upload my audio to a server?▼
No. The compression runs entirely in your browser using ffmpeg.wasm. Your audio file never leaves your device.