Base64 Encoder / Decoder

Encode and decode Base64 text with full Unicode support. Toggle URL-safe Base64, swap output back into input, and copy results with a click. All processing happens in your browser.

URL-safe

Input

Output

How to Use Base64 Encoder / Decoder

Convert text to Base64 and back, with proper Unicode handling and a URL-safe variant for tokens and query strings.

How to Use

Pick a mode: Encode (text to Base64) or Decode (Base64 to text)
Paste or type your input - conversion runs live as you type
Toggle "URL-safe" to use - and _ instead of + and /, with no padding
Click Swap to move the output into the input and flip the mode
Use the copy button to put the result on your clipboard

Features

Live Conversion: Output updates instantly on every keystroke
URL-Safe Variant: RFC 4648 base64url encoding for tokens, JWTs, and query strings
Unicode Safe: Uses TextEncoder and TextDecoder so emoji and non-ASCII characters round-trip correctly
Strict Validation: Catches malformed Base64 and invalid UTF-8 with a clear inline error
Client-Side Only: Your input never leaves your browser - nothing is sent to any server

Common Use Cases

API Debugging: Decode Base64 payloads from HTTP headers and responses
JWT Inspection: Decode the header and payload segments of a JSON Web Token
Data URLs: Encode small assets to embed in CSS or HTML
URL Tokens: Generate URL-safe identifiers and share links without escaping
Config and Secrets: Encode short text values for configuration files and environment variables