Audio converter

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.

Thirteen 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.
• M4A (AAC) is what iPhones, iTunes and video editors expect; ALAC is Apple Lossless in the same container, encoded with a port of Apple's own encoder. WavPack is lossless with the widest bit-depth support, common in archives.
• 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.