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GeekFormat

Audio to Base64

Drag audio here, or click on selection

Supports MP3, WAV, OGG, M4A, WebM and any other audio format. No file-size limit.

Convert MP3, WAV, OGG and other audio files to Base64 strings or Data URIs locally in your browser, ready for HTML5 embedding and API requests.

Related

Base64 to Audio

Text to Base64

Image to Base64

Video to Base64

File to Base64

URL Encode

Use Cases

  • Encode short audio clips as Base64 and embed them in HTML5 <audio> tags or CSS backgrounds to skip extra HTTP requests.
  • Send audio as a string inside JSON request bodies, WebSocket frames, or JWT payloads instead of multipart uploads.
  • Generate test payloads when debugging speech recognition, TTS, or other audio-processing APIs.
  • Decode a Base64 string back into a playable audio file to verify API responses or save assets offline.

Features

  • Broad audio format support: MP3, WAV, OGG, M4A, WebM and other browser-playable audio formats, with automatic MIME type detection.
  • Two output formats: switch between Data URI (with data:audio/mpeg;base64, prefix) and raw Base64 to match your embedding or transport target.
  • Built-in audio preview: play the uploaded file inline and inspect filename, size, and duration to verify file integrity.
  • Local-only processing: encoding runs in the browser via the FileReader API — your audio data never leaves your device.
  • Bidirectional: paste a Base64 string in the reverse mode to instantly decode it back into playable audio and download the file.
  • One-click copy and download: copy the Base64 string to your clipboard or save it as a .txt file for later use.

How to Use

  1. Drag-and-drop or click to upload a local audio file. MP3, WAV, OGG, M4A and other formats are supported, up to 20MB per file.
  2. The browser auto-detects the MIME type and encodes the file to Base64. Use the inline player to preview the audio and inspect its metadata.
  3. Switch between Data URI and raw Base64 to match your output target.
  4. Click copy to grab the string, or download it as a .txt file for later use.

FAQ

Does encoding audio to Base64 make the file larger?

Yes. Base64 increases the original data size by roughly 33% — a 1MB MP3 becomes about 1.33MB after encoding. For large files, prefer binary uploads or trim the clip first.

What is the difference between raw Base64 and a Data URI?

A Data URI looks like data:audio/mpeg;base64,xxx and can be used directly as an <audio> src or CSS background. Raw Base64 is just the encoded string and is best for JSON configs or API parameters.

Is my audio uploaded to a server?

No. All encoding runs locally in your browser using the FileReader API. Your audio never reaches a backend, so sensitive recordings stay private.

Which audio formats are supported, and what is the file size limit?

Any browser-playable audio format works, including MP3, WAV, OGG, M4A, and WebM. The per-file limit is 20MB; larger files trigger a warning.

Can I decode a Base64 string back into an audio file?

Yes. Switch to the B64→🎵 mode, paste your Base64 string, and the tool will play the audio and let you download the original file.