JWT Decoder
The JWT Decoder reads the header and payload of any JSON Web Token (RFC 7519) and displays them as pretty-printed JSON. The three base64url-encoded segments (header.payload.signature) are split apart and decoded; expiry (exp), issued-at (iat) and not-before (nbf) claims are additionally formatted as human-readable local timestamps. The signature cannot be verified without the secret or public key, so do not assume the message is authentically signed. The tool is read-only and runs entirely client-side; paste a JWT only into your own browser.
How to Use
To use the JWT Decoder, simply open the tool page and interact with the controls in the panel above. The interactive panel handles input and produces instant results entirely in your browser — no signup, no upload. Use the Copy button when you want to transfer the output to your clipboard.
Key Features
- Runs in your browser — No data uploads or server roundtrips.
- Free & no signup — Use without registration or limits.
- Privacy first — Your input never leaves your device.
- Instant results — All processing is synchronous and local.
- Copy & download — Copy output or download to a file when supported.
Common Use Cases
This tool is useful for developers, designers, testers, students, and anyone who needs a quick, browser-based utility without installing software.
Tips & Tricks
Bookmark the tool for quick access during your workflow. Combine it with the related tools listed below for end-to-end productivity.
Frequently Asked Questions
Is my JWT sent to a server?
No. Decoding is purely base64url decoding of segments present in the token. No server calls.
Can the JWT signature be verified?
No. Verification requires the secret (HMAC) or public key (RS256); this tool only decodes the header and payload.
Is it safe to paste any JWT?
If the JWT carries access to one of your accounts, do not share it. The tool processes locally but anyone who sees this browser might also see the data.
Does it support refresh tokens?
Yes. Any string that follows the JWT three-segment format is decoded, regardless of whether it is an id, access, or refresh token.
Can it decode encrypted JWTs (JWE)?
No. JWE requires a key to decrypt. Only signed JWTs can be inspected without keys.