JWT Decoder & Inspector
Decode and inspect JSON Web Tokens (JWT) online. View headers, payloads, claims, expiration status, and signatures 100% privately in your browser.
JWT Input Token
How do you decode a JWT token online?
Paste your JWT string into ToolJi's JWT Decoder and click 'Decode JWT'. The tool splits the token into Header (blue), Payload (amber), and Signature (rose), decoding Base64URL into readable JSON.
What is JWT Decoder & Inspector?
A JWT Decoder & Inspector parses JSON Web Tokens into their three dot-separated component parts (Header, Payload, and Signature) and decodes their Base64URL payloads into human-readable JSON code and registered claims.
Who Needs It?
Software developers, API engineers, QA testers, security researchers, and backend architects inspecting authentication tokens during development and debugging.
Problem Solved
Eliminates guesswork when inspecting user roles, issuer IDs, subject claims, and exact token expiration dates during OAuth2 or OpenID Connect development.
How to Decode and Inspect a JWT Token
- 1
Paste JWT Token
Paste your raw dot-separated JWT string into the editor box.
- 2
Click Decode JWT
Click the Decode JWT button to decode Header, Payload, and Signature parts.
- 3
Inspect Claims
View recognized claims (iss, sub, exp, iat, nbf) and expiration time remaining.
- 4
Copy or Download
Copy decoded Header or Payload JSON or download them to your device.
Common Uses for JWT Decoder & Inspector
Debugging OAuth2 and OpenID Connect (OIDC) authentication flows.
Inspecting user permission scopes and roles in authorization tokens.
Checking exact token expiration timestamps (exp) and issued dates (iat).
Verifying Base64URL encoded Unicode user details (Hindi, Arabic, Chinese, Emoji).
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Frequently Asked Questions
Is my JWT token uploaded to a server?
No. All Base64URL decoding, JSON parsing, claim extraction, and expiration calculations run 100% locally inside your web browser.
Does decoding a JWT verify its signature?
No. Decoding reads the token data but does NOT verify cryptographic authenticity. You can perform optional HMAC secret verification in the 'Verify Signature' tab.
Are JWT tokens encrypted?
Standard JWT tokens are Base64URL encoded, not encrypted. Anyone with the token string can decode and read its header and payload.
How does the tool calculate token expiration?
The tool compares the 'exp' (expiration time) Unix timestamp claim in the payload against your current browser clock time.
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