Base64 Encode/Decode

How to encode or decode Base64

1. Choose a tab: Text for strings, File → Base64 to turn any file or image into Base64, or Base64 → File to turn Base64 back into a downloadable file.
2. For text, type or paste your input and press Encode or Decode. Tick URL-safe to use - and _ with no padding, as used in JWTs and URLs.
3. For files, drop the file on the box. You get the Base64 string, a ready-made data URI, and copy buttons for an HTML <img> tag or a CSS url().
4. To decode a file, paste the Base64 or data URI. The tool detects the file type from its first bytes, shows a preview for images and lets you download it.

What is Base64?

Base64 is a way of writing binary data using only 64 safe text characters (A–Z, a–z, 0–9, + and /). It is used wherever binary data has to travel through a text-only channel: email attachments (MIME), data URIs in HTML and CSS, JSON APIs, HTTP Basic authentication headers and JSON Web Tokens. Every 3 bytes become 4 characters, so Base64 output is about 33% larger than the original.

Base64 is an encoding, not encryption. Anyone can decode it, so never use it to hide passwords or secrets.

This encoder handles Unicode correctly: text is converted to UTF-8 bytes before encoding, so emoji and accented letters round-trip without the garbled output that plain btoa() produces.

Privacy

All encoding and decoding happens in your browser with built-in JavaScript functions. Files are read locally and are never uploaded, so it is safe to use with private documents, keys and images.