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MP4 into MP3

How to convert MP4 into MP3

Free, fast, and 100% private — works on Windows, Mac, Linux, iPhone, and Android.

  1. 1

    Open the converter

    Visit mp4intomp3.com on any browser. No signup, no install — the page loads instantly.

  2. 2

    Add your MP4 file(s)

    Drag and drop one or many files onto the upload area, click the area to choose files, or paste a copied file from your clipboard.

  3. 3

    Choose your output format and bitrate

    Default is high-quality MP3 at 192 kbps. Pick 320 kbps for the highest MP3 quality, or switch to FLAC/WAV for lossless audio.

  4. 4

    (Optional) Tune advanced settings

    Trim a section, fade in or out, boost the volume, normalize loudness, change speed, or fill in ID3 tags like title and artist.

  5. 5

    Click Convert

    The converter processes everything in your browser. Watch the per-file progress bar — the longer or more files, the longer it takes (still typically under a minute).

  6. 6

    Download

    When a file is done, hit Download — or use Download All to grab the whole batch at once.

Tips for the best MP3 quality

  • • Use 320 kbps for music — anything lower is audibly different on good headphones.
  • • Use 96–128 kbps for spoken-word recordings to save space without losing clarity.
  • • Turn on loudness normalization for podcasts so episodes sound at the same volume.
  • • If you want to archive the audio, choose FLAC (lossless) instead of MP3.
  • • Add ID3 tags so your music app shows the right title, artist, and album.

How it works (under the hood)

We compile a small media-processing library to WebAssembly, a fast, secure binary format that runs inside your browser. When you drop in a file, we read it from your device, decode the audio track, optionally apply your selected effects, and re-encode it to your chosen format — all in memory. The encoded result is offered as a download. Nothing ever leaves your machine.

Troubleshooting

The page is loading slowly the first time

On first visit we download the conversion engine (~25 MB). It is cached afterwards.

My phone runs out of memory on a big file

Mobile devices have less RAM. Try converting a smaller file, or use a desktop browser for very large videos.

The conversion fails with an error

Refresh the page and try again. If the issue persists, report it via [email protected] with the file format and your browser version.