Audio Converter

How to use the audio converter

1. Open or drop an audio file — its duration, sample rate and channels are read straight away.
2. Choose MP3 or WAV, and a bitrate if you chose MP3. The estimated output size updates as you change them.
3. Convert, play the result in the preview player, then download it.

About this audio converter

Convert audio between popular formats. MP3, WAV, M4A, AAC, FLAC, OGG and Opus can all be read, and the output is MP3 or WAV — choose the format, set a bitrate for MP3, and download the result.

Everything runs in your browser. The file is decoded by the browser itself, resampled through an offline audio context and encoded in the page, so nothing is uploaded and there is no queue to wait in.

The output list is deliberately shorter than the input list. MP3 encoding is possible because LAME has a pure-JavaScript port small enough to load only when you convert something; AAC, OGG, Opus and FLAC would each need a separate WebAssembly codec, so they are read but not written rather than being offered and then failing.

Supported formats

Anything your browser can decode can go in — MP3, WAV, M4A, AAC, FLAC, OGG, OPUS, AIFF and most other common audio files. Output is MP3 and WAV.

That output list is shorter than most converters advertise, and the reason is worth stating plainly: a web page has no encoder built into it. MP3 works here because LAME has a pure-JavaScript port small enough to load on demand. AAC, OGG, Opus and FLAC would each need a separate WebAssembly codec, so they are not offered rather than being offered badly.

Popular conversions

These are the conversions this tool performs. Each is the same two steps — open the file, pick the output format — so the list is about what is possible rather than about separate pages.

Audio format guide

Choosing an output format is mostly a trade between size and fidelity, with compatibility deciding the close calls.

Which format should you choose?

• MP3 when compatibility and file size matter more than the last few per cent of fidelity. Nothing refuses to play an MP3.
• WAV when software needs uncompressed PCM — most editors and DAWs do, and it is the right choice for anything you will process further.
• FLAC when you want the original detail at roughly half the size of WAV. This tool does not write FLAC, but it reads it.
• M4A or AAC for Apple-oriented workflows and efficient streaming.
• OGG or Opus for web playback and voice, where Opus in particular is remarkably small for its quality.

Bitrate and quality

Bitrate is how many bits per second the encoder is allowed to spend, and for MP3 it is the only quality control that matters much. More bits mean a closer match to the original and a proportionally larger file — a 128 kbps file is exactly half the size of the same audio at 256 kbps.

Bitrate applies only to lossy formats. WAV stores every sample, so there is nothing to ration, which is why the control disables itself when WAV is selected rather than pretending to do something.

How to convert an audio file

• Choose or drag an audio file into the converter. It is decoded and its length, sample rate and channels are shown.
• Pick the output format. The panel beside it estimates the size before you commit to anything.
• For MP3, choose a bitrate. Sample rate and mono/stereo are under Advanced settings if you need them.
• Convert, then play the result in the built-in player to check it before downloading.

Common conversion examples

MP3 to WAV is useful when an editor refuses compressed input — but it does not restore anything. The detail MP3 discarded is gone, and the WAV is simply a larger container for the same audio. It will be roughly ten times the size for no gain in quality.

WAV to MP3 is the opposite and the more common case: a 40 MB recording becomes about 6 MB at 192 kbps, which is the difference between a file you can email and one you cannot.

FLAC to MP3 makes a portable copy while the FLAC stays untouched on disk — the usual reason for converting at all, and a case where keeping both is the point.

M4A to MP3 is a compatibility conversion. Both are lossy, so the audio is decoded and re-encoded, which loses a little more; at 256 kbps or above the difference is difficult to hear.

Your audio stays on your device

The file is decoded by your browser, resampled by an offline audio context and encoded by JavaScript running in the page. Nothing is uploaded, there is no server that could receive it, and the site is a set of static files with nowhere to send anything.

The practical consequences are that conversion speed depends on your device rather than on a queue, and that very long files are limited by your own memory — everything is held decoded, which is roughly 10 MB per minute of stereo audio.

Common uses

• Shrinking a large WAV recording to an MP3 small enough to send.
• Getting a WAV for an editor that will not open M4A or FLAC.
• Making a portable MP3 copy of a FLAC library while keeping the originals.
• Converting a stereo interview to mono at 16 kHz for transcription.

Frequently asked questions

What audio formats can I convert?

Input can be MP3, WAV, M4A, AAC, FLAC, OGG, OPUS, AIFF or anything else your browser decodes. Output is MP3 or WAV.

Can I convert WAV to MP3?

Yes. Choose MP3 and a bitrate — 192 kbps is a reasonable default — and the file is encoded in your browser. A 40 MB WAV becomes about 6 MB at that setting.

Can I convert MP3 to WAV?

Yes. The MP3 is decoded and written out as uncompressed PCM, at 16 or 24-bit. Expect the file to grow by roughly ten times.

Is converting MP3 to WAV lossless?

It adds no further loss, but it restores nothing. What MP3 compression discarded is gone permanently, and wrapping the result in WAV only makes the file larger. Convert to WAV because software needs PCM, not to improve quality.

Does converting audio reduce quality?

Converting to a lossy format does, and converting between two lossy formats does it twice, because the file must be decoded and re-encoded. Converting to WAV adds no loss at all. Encoding at 256 kbps or higher keeps the second pass hard to hear.

What bitrate should I use for MP3?

128 kbps is fine for speech and podcasts, 192 kbps is a sensible default for music, and 256 or 320 kbps for anything you want to keep. Higher settings cost size proportionally and give steadily less back.

What is the best audio format for quality?

WAV and FLAC both preserve every sample; FLAC is about half the size for identical audio, which makes it the better archive format. Among lossy formats, Opus is the most efficient and MP3 the most compatible.

What is the best audio format for small files?

Opus, by a clear margin, especially for speech. Among what this tool writes, MP3 at 128 kbps is the smallest option and is adequate for anything voice-based.

Can I convert FLAC to MP3?

Yes — FLAC decodes in most browsers and encodes straight to MP3 here. The original FLAC is not touched, so you end up with both.

Can I convert M4A to MP3?

Yes. M4A is a container, usually holding AAC, and browsers decode it; the audio is then re-encoded as MP3. Since both are lossy, use 256 kbps or above if quality matters.

Why can I not convert to AAC, OGG or FLAC?

Because a web page has no encoder for them. MP3 is possible because LAME has a small pure-JavaScript port; the others would each need a WebAssembly codec far larger than this entire site. They are left out rather than offered unreliably.

Are my audio files uploaded?

No. Decoding, resampling and encoding all happen in your browser, and the site is static with no server that could receive a file. Nothing leaves your device and nothing is stored.