Audio converter
Drop an audio file. Pick the format, sample rate, channels and quality. Tags carry over.
Nothing is uploaded. Everything runs in this tab with @audio/decode, @audio/encode, @audio/resample.
Convert audio without uploading it
This converter decodes with @audio/decode, resamples with @audio/resample and encodes with @audio/encode, open-source JavaScript and WebAssembly libraries from audiojs. Your file stays on your device; the page works offline once loaded. No account, no watermark, no queue, no size limit.
Ten output formats
- MP3 plays everywhere; 256 kbps is transparent for most material, 320 for archiving.
- WAV, AIFF, CAF are uncompressed PCM at 16, 24 or 32-bit float: editing, mastering, sample libraries.
- FLAC is lossless at about half the size of WAV; 16 or 24-bit.
- Opus and WebM give the smallest files at equal quality; 64 kbps Opus speech is already clean. Note that Safari does not play Ogg Opus in a browser player; the file itself is fine everywhere else.
- AAC is the format Apple devices and video containers expect. OGG Vorbis remains common in games and open-source tooling. QOA is a tiny fast lossy codec for games.
Sample rate, channels, bit depth, bitrate
Everything follows the source unless you change it. Set 16 kHz mono for speech-to-text pipelines, 44.1 kHz for CD-style delivery, 48 kHz for video, 96 kHz to match a session. Mono downmix averages the channels; stereo from mono duplicates.
Tags carry over
Title, artist, album, year, cover art and similar fields are read from the source and written into the target when the target format has a tag chunk (WAV, MP3, FLAC, AIFF, OGG, Opus). The file line shows the title and artist that were found.
Video files
MP4, MOV, MKV, WebM and AVI files are accepted too: their audio track is extracted and converted. See extract audio from video for the details.
Questions
Which formats can I convert from? MP3, WAV, FLAC, OGG Vorbis, Opus, AAC, M4A, ALAC, AIFF, CAF, WMA, AMR, AC-3, DTS and QOA, plus the audio track of MP4, MOV, MKV, WebM and AVI video.
Which formats can I convert to? MP3, WAV, FLAC, OGG Vorbis, Opus, AAC, AIFF, CAF, WebM (Opus) and QOA. Lossy formats take a bitrate (or a quality level for Vorbis); PCM formats take a bit depth of 16, 24 or 32-bit float.
Do the tags survive? Title, artist, album, year and the other common fields are read from MP3, FLAC, WAV, M4A, Ogg and Opus sources and written into WAV, MP3, FLAC, AIFF, OGG and Opus outputs.
Can I change the sample rate or make it mono? Yes. Pick a sample rate from 8 to 96 kHz (polyphase resampling with a Kaiser-windowed filter) and mono or stereo. Opus and WebM always run at 48 kHz internally.
Is the conversion lossless? WAV, FLAC, AIFF and CAF preserve every decoded sample at the chosen bit depth. Converting between two lossy formats re-compresses; keep a lossless master when you can.