Free Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to text — runs entirely in your browser.

Try it

How it works

The browser has built-in Base64 functions:

// Encode (with UTF-8 support)
btoa(unescape(encodeURIComponent(text)));

// Decode (with UTF-8 support)
decodeURIComponent(escape(atob(base64)));

The encodeURIComponent / unescape trick handles UTF-8 characters that btoa can’t process on its own.

When you’d use this

• Encoding API keys or credentials for HTTP headers (Authorization: Basic <base64>)
• Debugging JWT tokens (the payload is Base64-encoded)
• Embedding small images as data URIs in CSS/HTML
• Decoding Base64 blobs from APIs