File & PDF Tools

File Base64 Converter

Convert any file to or from Base64 and Data URLs.

File Base64 converter
Convert any file to or from Base64 text.
Local processing

File Base64 Conversion

Encode any file as raw Base64 or a MIME Data URL, or rebuild a file from Base64 input.

Usage

  • Input files for encoding are limited to 50 MB
  • Base64 is usually about one-third larger than the source file
  • Base64 is encoding, not encryption

Frequently Asked Questions

The file grew a lot after Base64 — is that normal?
Yes: Base64 encodes every 3 bytes as 4 characters, about 33% overhead. Inlining small images as Data URIs saves a request; large files do not benefit — they balloon and lose parallel download and independent caching.
Data URI versus plain Base64 — what is the difference?
Plain Base64 is just the data; a Data URI prefixes a type declaration: data:image/png;base64,xxxx. HTML and CSS require the prefixed form (the browser cannot guess the type); APIs usually take plain Base64 with the type agreed separately.
Is converting files here safe?
Entirely local — files never leave the browser, which is exactly why it suits contracts, scans, and ID photos. Remember Base64 is encoding, not encryption: anyone can decode the output, so add AES if confidentiality matters.