How to use this tool
- Paste plain text or a Base64URL string into the input.
- Choose Encode or Decode to run the conversion.
- Copy the result for use in tokens, URLs, or API payloads.
About Base64URL Converter
This tool converts between raw text and Base64URL, which uses - and _ instead of + and / and omits padding. It is useful for JWT segments, OAuth state parameters, and any context where standard Base64 characters are unsafe in URLs.
Common use cases
- Encoding JWT header or payload segments for manual token assembly
- Decoding Base64URL segments while debugging OAuth or auth flows
- Converting data for URL-safe transport in query params or paths
FAQ
- What is Base64URL and when should I use it?
- Base64URL is a URL-safe variant of Base64 that replaces + with - and / with _, and omits padding. Use it when encoding data for URLs, JWTs, or OAuth tokens where standard Base64 characters could cause issues.
- Does this tool send my data to a server?
- No. All encoding and decoding runs locally in your browser. Your input never leaves your device.
- Why does Base64URL omit padding?
- Padding (=) can interfere with URL parsing and is often omitted in JWT and OAuth specs. Decoders typically add padding as needed before decoding.
- Can I use Base64URL for secrets or passwords?
- Base64URL is encoding, not encryption. Anyone can decode it. Do not use it to protect sensitive data; use proper encryption and secret management instead.