Base64 encode Base64url (URL-safe)
Encode a value that will travel through a URL — query parameter, path segment, or token.
Example
Input
Hello+World/Stuff
Base64 output
SGVsbG8rV29ybGQvU3R1ZmY (Base64url, no padding)
The gotcha
Standard Base64 uses `+`, `/`, and `=` — all three are reserved or padding-sensitive in URLs. Base64url replaces `+` with `-`, `/` with `_`, and drops the `=` padding. JWTs and most OAuth flows use Base64url. Standard Base64 in a URL will break when proxies or framework routers decode percent-encoding.
When to use this
Any value that ends up in a URL. JWT components are Base64url-encoded by spec. OAuth state tokens, magic-link tokens, and webhook signatures often are too. When in doubt and the value travels via URL, use Base64url.
Open the encoder