Universal File to Base64 Converter

Convert any file (PDF, MP3, WOFF2, ZIP) to Base64 for JSON APIs with auto-detected MIME types

Drop any file or click to browse

PDF, MP3, ZIP, any format

🔒 All processing happens locally in your browser

How to Use Base64

Universal file converter with MIME type detection. Perfect for embedding fonts in CSS, PDFs in apps, or sending binary data via JSON APIs.

Input: document.pdf

Output: data:application/pdf;base64,JVBERi0xLj...

Input: font.woff2

Output: data:font/woff2;base64,d09GMgABAA...

How do I convert a file to Base64?

Upload any file (PDF, audio, font, etc.). The tool auto-detects the MIME type and outputs Base64 string and Data URI ready for use.

How do I decode Base64 back to a file?

Paste the Base64 string, click Download File. The tool detects the file type from the data and offers the correct download.

How do I send a file in a JSON API?

Convert to Base64, copy the JSON snippet. Paste into your API request body. Most APIs accept Base64-encoded file data.

What file types can I convert to Base64?

Any file type works. Common uses: PDFs, audio files (MP3, WAV), fonts (WOFF2, TTF), archives (ZIP). MIME type is auto-detected.

How do I embed fonts as Base64 in CSS?

Convert your WOFF2 or TTF file, copy the Data URI, use in @font-face src. This eliminates external font file dependencies.

What is the maximum file size for Base64 conversion?

Limited to 50MB for browser stability. Very large files may slow your browser. Consider compression first for large files.

How do I detect file type from Base64?

The tool examines the decoded data for file signatures (magic bytes). PDFs start with %PDF, PNGs have specific header bytes, etc.

Can I convert Base64 from an API response to downloadable file?

Yes. Paste the Base64 string from your API response, click Download File. The decoded binary file downloads with correct MIME type.

All processing happens in your browser. No data is sent to any server.