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Free File Converter

Audio converter

Convert an audio or video file to MP3, WAV, FLAC, OGG, Opus, or M4A.

Processed in your browser. This file is converted on your device and is never uploaded.

Converter

.mp3, .wav, .flac, .ogg, .opus, .m4a, .aac, .mp4, .mov, .webm, .mkv up to 250 MB. You can also drag a file here.

Options

The first conversion downloads a 32 MB audio engine, which is then reused while this page stays open. Conversion runs on your device and is much slower than a desktop program: expect roughly real time for a long recording, and considerably slower on a phone.

The engine is ffmpeg.wasm, an unmodified build of FFmpeg licensed under the GPL, version 2 or later. It is served from this site's own asset domain, because it is too large for the limit our host places on a single file. It receives nothing about your file: it is a program your browser downloads and then runs on your device.

Higher quality means a larger file. This has no effect on WAV or FLAC, which do not discard anything.

No file selected.

About this tool

Audio conversion is normally something you either install a program for or hand a private recording to a website you have never heard of. This tool does it with a build of FFmpeg compiled to WebAssembly, running inside your browser, so an interview, a voice memo, or an unreleased track never leaves your device.

MP3, WAV, FLAC, OGG Vorbis, Opus, and M4A are all supported as outputs, and most common audio and video files can be read as input.

Supported formats and limits

Input
.mp3, .wav, .flac, .ogg, .opus, .m4a, .aac, .mp4, .mov, .webm, .mkv
Output
.mp3 (audio/mpeg)
Output name
The original name with the chosen format's extension, for example song.wav becomes song.mp3.
File size limit
250 MB
Processing
In your browser. The file is not uploaded.

How to use it

  1. Choose an audio or video file.
  2. Pick the output format, and a quality level if the format has one.
  3. Select Convert. The first conversion downloads the audio engine, which takes a moment.
  4. Download the converted file.

Limitations

  • The first conversion downloads a 32 MB engine. It is reused while the page stays open, but reloading the page fetches it again.
  • Conversion is much slower than a desktop program, because it runs in your browser rather than on your processor directly. A long recording can take several minutes, and considerably longer on a phone.
  • Large files can exhaust memory, particularly on mobile devices. The limit is 250 MB, but a phone will struggle well before that.
  • Converting between lossy formats, such as MP3 to OGG, means a second round of quality loss. Convert from the original whenever you can.
  • Tags and cover art are not preserved.
  • Only the audio is kept. Feeding in a video produces a soundtrack, not a video file.
  • Every output format offered here is tested by converting a real file and decoding the result in a browser, so the list reflects what the bundled engine can actually do.

Frequently asked questions

Is my file uploaded?
No. The conversion runs entirely in your browser. The only network request is for the conversion engine itself, which is served from this site and carries nothing about your file.
Why is the first conversion slow to start?
The engine is a 32 MB WebAssembly build of FFmpeg and has to be downloaded and compiled before anything can be converted. Later conversions on the same page reuse it.
Which format should I choose?
MP3 for maximum compatibility, Opus for the best quality at a given size, FLAC to keep every bit of the original, and WAV when a piece of audio software insists on uncompressed input.
Can I convert a whole album at once?
Not yet. One file is converted at a time, which also keeps memory use predictable.

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