Omikuji Tools Image & Video

Audio Converter

Convert MP3, WAV, M4A, FLAC or the audio of a video into WAV, M4A (AAC) or WebM (Opus), with trimming and mono conversion. Your audio is never sent to a server.

✨ Features

  • Reads MP3, WAV, M4A (AAC), OGG, FLAC, Opus and the audio of MP4, MOV and WebM videos
  • Exports WAV (16 / 24 / 32-bit), M4A (AAC) or WebM (Opus) at 64–256 kbps
  • Trim to a start and end time — play the audio to pick the exact spot
  • Convert to mono and change the sample rate (48 kHz, 44.1 kHz, 16 kHz and more)
  • Extract just the audio from a video file

🪄 Use cases

Extract audio from a video

Save the audio of a recorded meeting or talk as M4A to listen on the go or send for transcription.

Prepare audio for editing software

Turn MP3 or M4A into WAV for video editors and DAWs.

Shrink recordings for speech recognition

Convert long recordings to mono 16 kHz before uploading them to a transcription service.

Make ringtones and sound effects

Cut out just the part of a song or recording you want as a short clip.

🔒 Privacy

Reading, trimming and converting all happen inside your browser, on your own device. Audio and video files are never uploaded to a server, so you can convert recorded meetings or private calls without them leaving your device. Files are not stored in the URL or in localStorage and are gone when you close the page.

❓ FAQ

Is my audio uploaded?

No. Decoding is done by the browser's Web Audio API and compression by the browser's WebCodecs (your operating system's audio encoders), so the file never leaves your device. Once the page has loaded, it works offline too.

Why can't I convert to MP3?

Browsers have no built-in MP3 encoder, and every MP3 encoder that can be shipped to a web page is based on LAME, which is licensed under the LGPL. This site only uses components with clear, permissive licensing, so MP3 export is not included. You can still convert MP3 files into other formats. If you need a format that plays everywhere, choose M4A (AAC) — at the same bitrate it sounds as good as MP3 or better.

Why is M4A (AAC) unavailable?

AAC export uses the audio encoder built into your operating system, so some browser and OS combinations lack it (for example Chrome on Linux, and Firefox). It is available in Chrome / Edge on Windows, macOS and Android, and in Safari on macOS and iPhone. WAV export works in every browser.

Which format and quality should I pick?

For listening on a phone or in the car, M4A (AAC) at 128–192 kbps; for voice-only recordings, M4A at 64–96 kbps is plenty. For video or music editing software, choose WAV (16-bit). WebM (Opus) gives the smallest files.

Can I convert long recordings?

The decoded audio is held in memory, so it depends on your device. Computers handle one to two hours without trouble, but phones may fail on long recordings. If that happens, trim the audio and convert it in parts.

Can I extract just the audio from a video?

Yes. Drop in an MP4, MOV or WebM video and only the audio track is read. The video is not loaded and is not included in the output. Videos your browser cannot play (some MKV or AVI files) may not load.

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Open an audio or video file

Drag and drop an audio or video file here

Or click to choose a file. Works with anything your browser can read: MP3, WAV, M4A, AAC, OGG, FLAC, Opus, and MP4 / MOV / WebM videos (only the audio is used).

Choose a file

Settings

Output format

WAV is uncompressed: quality is untouched but files are large (about 10 MB per minute at CD quality). Best for loading into editing software.

Trim

Enter times like "1:30", "90" or "1:02.5" (minutes:seconds.fraction). Leave empty for the very start or end. Play the audio above, pause, then press Playhead to fill in that time.

Privacy

Reading, trimming and converting all happen inside your browser, on your own device. Audio and video files are never uploaded to a server, so you can convert recorded meetings or private calls without them leaving your device. Files are not stored in the URL or in localStorage and are gone when you close the page.