Base64 Encode / Decode

Base64 represents any bytes using only 64 safe characters (A-Z, a-z, 0-9, +, /), with = as padding. It exists so that binary data or arbitrary text can pass through channels that only accept plain text: HTTP Basic authentication headers, data: URLs, email attachments, JSON fields, and Kubernetes secrets.

Base64 is an encoding, not encryption. Anyone can decode it, so it hides nothing. The output is also about a third larger than the input, since every 3 bytes become 4 characters.

The browser's built-in btoa() function fails on any character outside Latin-1, so btoa("✓") throws an error. This tool first converts your text to UTF-8 bytes and then encodes those bytes. That is how most servers and libraries do it, so the output matches Python's base64.b64encode(s.encode()) or echo -n ... | base64 on the command line.

Decoding reverses the process and reads the bytes as UTF-8. Spaces and line breaks in the input are ignored, so Base64 wrapped at 76 characters, as in email bodies and PEM files, decodes without cleanup.

This is a text tool. Decoding Base64 that represents an image, a PDF, or another binary file produces unreadable characters, because those bytes are not text. URL-safe Base64, which uses - and _ instead of + and / (as in JSON Web Tokens), needs those two characters swapped back before decoding. Missing padding may also need adding.