05 // Unicode, Symbol & Encoding WorkbenchBASE64-CODEC
Base64URL (RFC 4648 §5) URL-Safe Encoder & Decoder
Base64URL replaces `+` with `-`, replaces `/` with `_`, and strips trailing `=` padding so encoded tokens pass safely inside URL query parameters and HTTP paths without `%` escaping.
Encoded Output
ZXlKaGJHY2lPaUpGVXpJMU5pSXNJblI1Y0NJNklrcFhWQ0o5
Decoded Output
{"alg":"ES256","typ":"JWT"}Was this tool helpful?
Reference Table
- 01Used by JSON Web Tokens (RFC 7519), OAuth 2.0 PKCE `code_challenge`, Passkeys/WebAuthn credential IDs, and YouTube 11-character video IDs.
Frequently Asked Questions
How does Base64URL differ from standard Base64?+
Index 62 uses `-` instead of `+`, index 63 uses `_` instead of `/`, and `=` padding is omitted because `+`, `/`, and `=` are reserved URI delimiters.
How do I restore stripped `=` padding before decoding Base64URL?+
Append `(4 - (str.length % 4)) % 4` `'='` characters after replacing `-` → `+` and `_` → `/`.
Does this tool transmit my tokens to any server?+
Never — 100% of encoding and decoding executes locally in your browser's JavaScript memory.