MP3 to Base64 Converter Online - Free, No Upload

Pick an MP3 above and you get its Base64 string plus a working HTML audio tag you can paste as it is. A player appears on the page too, so you can check you picked the right track.

The file is read by your browser, not sent to us. No upload wait, no size cap, no signup. It is free.

How to Convert an MP3 to Base64

1. Click Select MP3 and pick your audio file.
2. A player and the code blocks load underneath.
3. Hit Copy To Clipboard, or Download Text to save the string as a .txt file.

Long tracks take a few seconds. That is your own device doing the encoding, not a slow server.

The Audio Tag It Gives You

The HTML block is a full audio element with the data URI already in the src. Paste it into a page and it plays, with no audio file to host anywhere.

The Base64 block below it is the same data URI on its own. That is the one to use for a JSON field, a config file, or an API that wants the string by itself.

Audio Files Are Big - Do the Math First

Base64 packs every 3 bytes into 4 characters, so the string comes out about 33% bigger than the file. A 5 MB MP3 becomes roughly 6.7 MB of text.

That is fine for a short notification sound of 20 KB or so. It is a bad idea for a full song. An inlined track cannot be cached on its own and it has to download completely before anything plays.

Our honest advice after testing this: inline short clips, link real music. Under about 100 KB the convenience wins. Above that, a normal file and a plain URL beats it every time.

Your Audio Never Uploads

Most converters send your file to a server, encode it there, and return the text. This page does not. Your browser reads the audio with the FileReader API and does the work on your machine.

That matters for a voice note, a client recording, or an unreleased track. There is no copy sitting in an upload folder, because there was never an upload.

MP3 to Base64 for WAV, OGG and Other Formats

The picker takes any audio file your browser can open. WAV, OGG, M4A and FLAC all work the same way.

The data URI prefix changes to match, so a WAV comes out as data:audio/wav;base64,. Keep that prefix if you are pasting into HTML. Strip it if an API asks for raw characters.

Decoding Audio Back From a String

Need the file back from a string? The Base64 decoder handles images, and Base64 to PDF handles documents.

For any other format, file to Base64 takes whatever you give it and returns the raw string with its MIME type.