JWT Decoder

Decode and inspect JSON Web Tokens (JWT), with signature verification support

What is a JWT Decoder?

A JWT decoder is a free online tool for decoding and inspecting JSON Web Tokens. It decodes a JWT into its header and payload parts, displays them in a readable format and checks the expiration status. All decoding happens in the browser.

How to decode a JWT

Paste the JWT into the input field. The tool decodes it automatically and displays the header and payload in JSON format. It also shows whether the token has expired.

Understanding the JWT structure

A JWT consists of three parts: the header (contains the algorithm and token type), the payload (contains the claims, i.e. the data) and the signature (used to verify that the message was not changed). The parts are separated by dots (.).

Common use cases for JWTs

  • Authentication tokens for web applications
  • Sharing user information across domains
  • Representing user permissions and roles
  • Securely transferring data between microservices
  • Implementing stateless session management

Frequently Asked Questions

What is a JWT?+
A JWT (JSON Web Token) is a compact, URL-safe format for representing claims between parties. It consists of three parts — header, payload and signature — encoded in Base64URL and separated by dots (.).
How do I decode a JWT?+
Paste the JWT into the input field. The tool decodes it automatically and displays the header and payload parts in a readable format. It also checks whether the token has expired.
Can this tool verify JWT signatures?+
No. This tool only decodes JWTs without verifying the signature. Verification requires the key used to sign the token. Always verify JWTs on the server side.
Are JWTs secure?+
JWTs can be used securely, but must be implemented correctly. Always verify the signature, check the expiration time, do not store sensitive data in the payload (it is Base64 encoded, not encrypted), and use HTTPS in transit.
What are common use cases for JWTs?+
JWTs are commonly used for authentication (after login, the server returns a JWT that the client stores), information exchange (securely transferring information between parties) and authorization (representing user permissions).
Is decoding a JWT safe?+
Yes. This tool decodes JWTs locally in the browser. No data is sent to any server. However, do not store sensitive information in client-side JWTs, because anyone can decode them.

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JWT Decoder — free online jwt decoder, decode jwt, jwt viewer, json web token, jwt parser, jwt token decode, jwt header payload, jwt verification. No signup required. Works in your browser.