Convert PDF to Base-64 Online with pdfwin

Encode a PDF to Base64 String

Convert any PDF file into a Base64-encoded text string. Useful for developers who need to embed PDFs in JSON API responses, HTML data URIs, or email bodies.

How it works

1. Upload your PDF file.
2. Click Encode to Base64.
3. Copy the Base64 string or download it as a .txt file.

Tips for best results

• Base64 strings are approximately 33% larger than the original file.
• For use in an HTML or tag, prefix the string with data:application/pdf;base64,

Frequently asked questions

Can I use this Base64 string directly in an API?

Yes - most REST APIs that accept document uploads support Base64-encoded file content in JSON payloads.