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.

Do I need to install anything or create an account to use Audio converter?

No, to all of it. Audio converter runs inside the browser you already have, with no sign-up, no download, no watermark on the result, and no cap on how many files you convert. There is nothing to uninstall afterwards either, because nothing was installed.

Does Audio converter work offline?

After the first conversion, yes. Audio work needs the FFmpeg engine, which is a separate download of a few tens of megabytes fetched the first time you convert something. Once your browser has cached it the work is entirely local and a connection is no longer needed.

How large a file can Audio converter handle?

The limit is 250 MB. It is a deliberate one rather than a technical ceiling: the real constraint is memory, and a file that decodes to more than the device can hold fails in a way that is hard to explain. Phones run out well before laptops do, which is why the limit is set where it is.

Can I convert several files at once with Audio converter?

Not here: this tool takes one file at a time, because what it does depends on choices you make about that particular file. Convert them one after another, or look at the batch converters in the same category, which are built for a folder at a time.

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.

Choose a file

.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.

Output format

QualityHigher 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

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

Common problems

The file was refused before anything started.

Audio converter checks the extension before it reads a byte, and it accepts .mp3, .wav, .flac, .ogg, .opus, .m4a, .aac, .mp4, .mov, .webm, .mkv. Browsers report file types inconsistently enough that the extension is what decides.

Rename the file if the extension is simply wrong, or convert it to one of those first. A file whose extension does not match its contents is refused for the same reason, and that one needs converting rather than renaming.

It said the file was too large.

The limit here is 250 MB. It is not a policy but a measurement: everything runs on your own device, and past that size a phone runs out of memory rather than finishing slowly.

Split the file, reduce it before converting, or use a desktop program for that one. A machine with more memory will manage more, but the limit does not know which machine it is on.

I selected several files and only one converted.

This tool takes one file at a time. Doing several at once would multiply the memory in use, which is the thing most likely to fail on a phone.

Convert them one after another. Nothing is kept between them, so there is no state to reset.

Nothing happened for a long time on the first run.

Audio converter downloads a library before it can begin, and it is fetched once and then reused. That wait is before the conversion rather than during it, which is why the progress bar sits still.

Leave the tab open and in the foreground; a background tab is throttled by the browser. Every conversion after the first one in a session skips this.

The tab reloaded itself part-way through.

The browser ran out of memory and restarted the page. At sizes approaching 250 MB this is the failure a phone hits first, and it looks like a crash rather than an error.

Try a smaller file, close other tabs, or run it on a computer. Nothing was uploaded or lost — the original file is untouched on your device.

The result opened in the wrong program.

The output is a .mp3 file, and your system opens that extension with whatever it was told to. Nothing about the conversion decides it.

Open it from inside the program you want, or change the default for .mp3 in your system settings. The file itself is correct.

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.
Do I need to install anything or create an account to use Audio converter?: No, to all of it. Audio converter runs inside the browser you already have, with no sign-up, no download, no watermark on the result, and no cap on how many files you convert. There is nothing to uninstall afterwards either, because nothing was installed.
Does Audio converter work offline?: After the first conversion, yes. Audio work needs the FFmpeg engine, which is a separate download of a few tens of megabytes fetched the first time you convert something. Once your browser has cached it the work is entirely local and a connection is no longer needed.
How large a file can Audio converter handle?: The limit is 250 MB. It is a deliberate one rather than a technical ceiling: the real constraint is memory, and a file that decodes to more than the device can hold fails in a way that is hard to explain. Phones run out well before laptops do, which is why the limit is set where it is.
Can I convert several files at once with Audio converter?: Not here: this tool takes one file at a time, because what it does depends on choices you make about that particular file. Convert them one after another, or look at the batch converters in the same category, which are built for a folder at a time.

Converter