This online JWT Decoder, Validator & Generator helps you inspect,
validate
and cryptographically verify JSON Web Tokens directly in your browser. Unlike basic
JWT decoders, this tool performs real signature verification
for HS256, HS384 and HS512
along with standard claim validation for exp, nbf,
iat, iss and aud.
Built for developers who need more than just decoding —
this is a secure, open and privacy-first alternative to jwt.io.
This JWT is auto-generated to help you understand how headers,
claims, and signatures work together.
All processing happens locally using the browser’s
WebCrypto API.
Your tokens and keys are never sent to any server, making this tool safe for
debugging
production JWTs.
Why Use Our JWT Tool?
Compare performance, security, and usability versus other popular JWT tools like
jwt.io.
Benchmark: Devglan JWT Tool vs jwt.io
Feature
Devglan JWT Tool
jwt.io
Decode JWT
✔ Yes
✔ Yes
Validate claims (iss, aud, exp, nbf, iat)
✔ Yes
✖ No
HS256, HS384, HS512 support
✔ Yes
✔ Only HS256 & HS512
Signature verification client-side
✔ Yes
✔ Yes
Color-coded JWT segments
✔ Yes
✖ No
Fully client-side, no server calls
✔ Yes
✔ Yes
JWT generator with custom payload
✔ Yes
✔ Limited
About JWT (JSON Web Token)
A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties.
JWTs are widely used for API authentication, single sign-on (SSO), and securely transmitting
information between client and server. Learn more at JWT.io and
Auth0's JWT guide. You can also follow this tutorial to implement the JWT based auth mechanism in spring boot.
JWTs consist of three parts: Header, Payload (claims), and Signature. Our tool helps you decode, validate claims, and verify signatures directly in your browser, without sending sensitive data to any server. For official specs, check RFC 7519.
Use Cases
Decode JWTs from APIs to inspect claims.
Validate expiration (exp) and not-before (nbf) fields.
Verify HS256, HS384, HS512 signatures locally.
Generate test JWTs for development or API testing.
HS256, HS384, HS512 signature generation and verification entirely client-side.
Color-coded JWT segments for easier visualization.
Copy JSON payload or generated JWT with one click.
Safe and private: no data is sent to any server, reducing risk of exposure (see OWASP guidelines).
Key Terminologies
Header: Contains metadata about the token, including the algorithm (alg) used.
Payload: The claims or statements about an entity, e.g., user ID, roles, or permissions.
Signature: Ensures token integrity and authenticity.
Claims: Pieces of information asserted about the subject (iss, aud, exp, etc.).
HS256 / HS384 / HS512: HMAC with SHA-256, SHA-384, SHA-512 algorithms used to sign tokens.
Frequently Asked Questions
Paste your JWT into the decoder section. The tool will display the header, payload, and signature, color-coded for clarity.
Yes! Enter the secret key in the signature verification section. The tool verifies the signature entirely in your browser.
No. All decoding and verification is performed client-side. Your JWT and secret never leave your browser.
Typical claims include iss (issuer), sub (subject), aud (audience), exp (expiration), nbf (not before), and iat (issued at). More details can be found at JWT.io.
