Base64 to Audio Converter
Everything is decoded in your browser. No audio is uploaded.
Ignored when the input is a full data URL, which carries its own type.
The base64 to audio converter decodes a base64 payload into a playable audio file, with a player for checking it and a download for keeping it. Unlike images, audio formats cannot be reliably identified from a bare payload, so the format selector matters when the input has no data URL prefix.
How it works
The decoded bytes are handed to the browser as a data URL with a declared MIME type. Getting that type wrong is the usual reason a valid file will not play, the browser trusts the declaration over the file contents.
- MP3 payloads usually begin SUQz, which is the base64 encoding of the ID3 tag header.
- WAV payloads begin UklGR, from the RIFF header.
- OGG payloads begin T2dnUw, from the OggS signature.
- A data URL carries its own type, in which case the selector is ignored.
Only the first few characters are test-decoded before the player is built. Audio payloads run to megabytes, and decoding the whole thing twice (once to validate, once to play) would stall the page for large files.
Examples
An MP3 payload
Input
SUQzBAAAAAAA... with format set to MP3
Result
A working player, plus a download button
SUQz decodes to "ID3", the tag header that starts most MP3 files. Recognising these prefixes is the quickest way to pick the right format.
The wrong format selected
Input
A WAV payload with format set to MP3
Result
The player appears but will not play
The browser trusts the declared MIME type over the file contents, so a mismatch produces a silent failure rather than an error. Switching the selector to WAV fixes it.
Frequently asked questions
Why does the player appear but produce no sound?
Almost always the wrong format selected. The browser trusts the MIME type you declare rather than inspecting the bytes, so a WAV payload declared as MP3 loads and then fails silently. Check the payload prefix, SUQz for MP3, UklGR for WAV, T2dnUw for OGG.
Can I tell the format from the base64 itself?
Usually, from the first few characters, because they encode the file signature. That is why the tool lists the common prefixes. It is faster than trying each format in turn.
Is there a size limit?
Practically, yes. Base64 audio runs to megabytes of text, and pasting tens of megabytes into a textarea will make any browser struggle. For large files, decoding with a command-line tool is more comfortable.
Is the audio uploaded anywhere?
No. The payload is turned into a data URL in your browser and handed straight to the audio element. Nothing is sent over the network.