Base64
Encode and decode Base64 in both directions, from text or a file. It handles UTF-8 correctly — accents and emoji survive the round trip — and offers the URL-safe variant used in JWTs and query strings.
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How it works
Conversion uses the browser TextEncoder together with btoa/atob. Plain atob breaks on anything outside Latin-1, so the tool converts to UTF-8 bytes before encoding, which is what virtually every language expects.
- Text to Base64 and Base64 to text, with automatic detection
- URL-safe variant (+ becomes -, / becomes _, no padding)
- File to data URI, ready to paste into CSS or HTML
- Tells you when the input is not valid Base64 instead of returning garbage