// tools
Base64 encoder / decoder
Type into either box; the other updates as you type. UTF-8 safe (emoji and non-ASCII characters work). Toggle URL-safe encoding for tokens you intend to put in URLs (replaces +/= with -_ and trims padding).
When to use URL-safe
Standard base64 uses +,/, and = — each is reserved or special in URLs. JWTs and many APIs use the URL-safe variant (RFC 4648 §5) so the same value can ride in a query string without escaping. If you're hand-decoding a JWT segment, switch to URL-safe mode here so the input is accepted.