~/tools/base64

Base64 encoder/decoder

UTF-8-safe Base64 encoding and decoding, standard or URL-safe. Runs entirely in your browser — no backend, nothing you enter leaves this page.

Input

URL-safe alphabet

Output

Encoding is UTF-8 safe: text is converted to bytes with TextEncoder before Base64 conversion, so multi-byte characters round-trip correctly. The URL-safe option uses the RFC 4648 §5 alphabet (+ becomes -, / becomes _) and omits = padding; padding is restored automatically when decoding.

Everything happens in this page’s JavaScript — no backend, nothing you enter leaves your browser.