Converters Audio
MP3, M4A and WAV in every direction, with the bitrate under your control.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
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Audio converter
Convert between MP3, M4A, WAV, AAC, OGG and FLAC in batches, with the bitrate under your control.
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MP3 converter
Turn any audio or video file into MP3, at a bitrate you choose, without uploading it anywhere.
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M4A to MP3
Convert iPhone voice memos, iTunes tracks and other M4A files to MP3 that anything will play.
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WAV to MP3
Compress large WAV recordings into MP3 at a bitrate you choose, without uploading anything.
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MP3 to WAV
Decode MP3 files to uncompressed 16-bit WAV for editing, transcription and software that refuses compressed audio.
The formats, and when each one is right
| Format | Compression | Use it for |
|---|---|---|
| MP3 | Lossy | Anything that has to play everywhere. Car stereos, old players, every phone. |
| M4A (AAC) | Lossy | Apple devices, and any case where you want better sound than MP3 at the same size. |
| WAV | None | Editing, mastering, and transcription tools that refuse compressed input. |
| FLAC | Lossless | Archiving. Around half the size of WAV with every sample preserved exactly. |
| OGG Vorbis | Lossy | Games and open-source projects that want no patent questions. |
Converting between lossy formats loses quality twice
MP3, M4A, OGG and AAC all work by discarding sound the ear is unlikely to notice. Converting one to another means decoding the first set of discards and then applying a second, different set on top. The result is always worse than either would have been from the original, however high you set the bitrate.
That is not a reason to avoid it. The difference is usually inaudible at 192 kbps and above, and compatibility often matters more than a difference nobody can hear. It is a reason to convert from the best copy you have rather than from something already converted twice.
What bitrate to pick
- 320 kbps for music you are keeping, or anything headed for a good pair of headphones.
- 192 kbps is the sensible default, transparent to most listeners on most material.
- 128 kbps for speech, podcasts, lectures and voice notes. Half the size, no audible cost on a voice.
- 96 kbps for a voice recording you need to email, where size beats everything.
WAV and FLAC ignore the setting entirely, because neither throws anything away. A WAV written here is 16-bit, 44.1 kHz stereo, which is CD quality and what every editor and transcription service expects to be handed.
Nothing is uploaded
Voice memos, interview recordings, therapy sessions, legal dictation: audio files are often more sensitive than the video they came from. Everything here is decoded and re-encoded inside your browser tab by a copy of FFmpeg running on your own machine, so there is no server holding a copy and no privacy policy to take on trust.
