Base64 to MP3 Converter
Paste the Base64 and download the audio file. The format is identified from the bytes themselves — an MP3 starts with an ID3 tag or a frame sync pattern — so a wrong or missing file name does not throw it off.
Processed as you paste — no button to press (Ctrl+Enter converts now / Esc clears)
Drop a file here, or — Ctrl+V a screenshot works too
Any file type · 100 MB maximum
Paste, drag and drop, or Ctrl+V a screenshot
Why audio is often shipped as Base64
- Voice-note and TTS APIs — synthesis endpoints commonly answer with a Base64 field
- Messaging platforms — media relayed through JSON webhooks
- Notification services — short alert sounds embedded in config
Recognition comes from the frame header
MP3 files begin with an ID3 tag or a frame sync (FF FB, FF F3 and similar). Other audio formats have their own signatures — RIFF for WAV, OggS for Ogg, ftyp for M4A. Checking those is why the download arrives with a usable extension.
A note on size
Audio grows fast under Base64: a 5 MB MP3 becomes about 6.7 MB of text, and the browser holds both copies while decoding. Voice notes are fine; full-length tracks are better handled as files.
Frequently asked questions
Can it play the audio on the page?
This page restores the file for download. Once you have the MP3, any player will open it — the advantage here is getting the original bytes back rather than a re-encoded copy.
The decoded output is not an MP3 — why?
The payload is a different format, or the data was truncated. The tool reports the detected type from the header, which tells you which of the two it is.
Can it handle very large audio files?
Up to 100 MB of input. Beyond a few megabytes the decode runs on a background thread so the page keeps responding.