Audio converter — free online tool

Convert audio to MP3, M4A or WAV with bitrate from 96 to 320 kbps, sample rate and mono or stereo choices, directly in the browser.

Audio

Convert audio to MP3

Choose a file, adjust the edit, preview the result, and export it.

Or drop an MP3, WAV, M4A, AAC, FLAC, OGG, Opus, or WebM audio file anywhere on this page.

Processed audio will appear here.

What to know

The converter reads MP3, WAV, M4A, AAC, FLAC, OGG, Opus and WebM audio and writes one of three targets: MP3 through the LAME encoder, M4A as AAC, or uncompressed 16-bit PCM WAV. The target chosen in the Export format menu decides which of the other controls appear.

MP3 and M4A show an Audio quality menu with 96, 128, 192, 256 and 320 kbps, and 192 is preselected. WAV hides that menu, since PCM has no bitrate: its size is fixed by sample rate and channel count alone.

Sample rate can stay as in the source or be forced to 22.05, 32, 44.1 or 48 kHz, and Channels can stay, collapse to mono or expand to stereo. Dropping a spoken-word recording to mono at 22.05 kHz is the quickest way to shrink it, because the data rate falls to a quarter of a 44.1 kHz stereo file.

Size is easy to predict. A 5-minute stereo WAV at 44.1 kHz is 300 s x 176,400 bytes, about 52.9 MB, while the same five minutes as MP3 at 192 kbps is 300 s x 24,000 bytes, about 7.2 MB. Each result is named after the source with the mode and new extension added.

Converting between two lossy formats, for example M4A to MP3, decodes and encodes again, so quality can only stay level or drop. Keep the original when archive quality matters.

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How to use Audio converter — free online tool
  1. Drop a file such as lecture.flac or voice-note.m4a into the audio box.
  2. In Export format choose MP3, M4A or WAV; for MP3 or M4A leave Audio quality at 192 kbps, or set 320 kbps for music.
  3. Set Sample rate to 44.1 kHz and Channels to Stereo, or choose 22.05 kHz and Mono for a small speech file.
  4. Run the conversion, play the result in the preview player and press Download.

Quick answers

Why does the quality menu disappear when I pick WAV?

WAV here is uncompressed 16-bit PCM, which has no bitrate to choose. Its file size depends only on sample rate, channels and duration.

Will converting M4A to MP3 improve the sound?

No. Both are lossy, so the audio is decoded and compressed again and cannot regain detail that the first encode removed.

How small can I make a one-hour talk?

At 96 kbps MP3 in mono the file is about 43 MB per hour (12,000 bytes per second x 3,600). Lowering the sample rate to 22.05 kHz keeps speech clear while using the same bitrate budget well.

What does Keep source do for sample rate and channels?

It passes the original value through untouched. Choose a fixed value only when a device or editor asks for it.