Free JWT Token Decoder & Inspector

Decode and inspect JSON Web Tokens (JWT) instantly in your browser. View header parameters, payload claims, and token expiration with complete privacy.

At a glance

JWT Token Decoder & Inspector is a free web tool that decodes and inspects JSON Web Tokens (JWT) safely in your browser. Clean, indented JSON inspection with one-click clipboard copying. It also instantly visualizes whether a token is active, expired, or premature with human-readable timestamps. Your inputs never leave your device, and there is no sign-up or install.

100% In-Browser Privacy

Tokens, authorization headers, and API secrets are decoded strictly within local browser memory. Zero server uploads.

Private & Offline
JWT Token Inspector
0 chars
Token Structure Breakdown
Paste a token above to inspect components...
Header Payload Signature
Awaiting Token
Algorithm: None
Header Parameters (JOSE)
Payload Claims (Data)
Signature Token Base64URL
Signature segment will appear here...

Cryptographic signatures are verified by the resource server using its secret or public RSA/ECDSA key.

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Why Use This JWT Token Decoder & Inspector?

100% In-Browser Privacy: Tokens, credentials, and API secrets are decoded strictly within your browser memory.
Automatic Expiry & Validity Check: Instantly visualizes whether a token is active, expired, or premature with human-readable timestamps.
Color-Coded Token Breakdown: Easily distinguish Header, Claims Payload, and Signature components.
Formatted JSON Claims: Clean, indented JSON inspection with one-click clipboard copying.

How to Use JWT Token Decoder & Inspector

1

Paste Your JWT

Paste your encoded JSON Web Token or authorization header into the input box.

2

Inspect Claims & Expiration

Review the decoded header parameters, payload claims, and live expiration status.

3

Copy Formatted JSON

Click Copy to export formatted claims or header objects for your API requests or debugging logs.

Worked example: Decoding Header and Payload Claims

The engine splits the token into 3 dot segments, Base64URL-decodes header and payload with atob plus TextDecoder, parses JSON and checks exp/iat/nbf against Date.now for validity.

JWT Token Input Source 
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
Decoded Header and Payload Processed 
Header: {"alg":"HS256","typ":"JWT"} | Payload: {"sub":"1234567890","name":"John Doe","iat":1516239022}

Technical Specifications & Engine Details

Technical specifications and engine details for JWT Token Decoder & Inspector
Specification Details
Supported Formats JWT, TXT → JSON
Execution Mode 100% Client-Side In-Browser (client)
Browser Requirements Requires modern web browser with Web Cryptography API (SubtleCrypto).
Performance Constraints Client browser memory limit (typically 1–2 GB RAM); processing speed depends on local device CPU.
Maintained by Pragyan Pahadi

100% Client-Side Privacy Guarantee

Your JWT tokens and authentication credentials remain strictly within your browser memory. Zero network requests are made.

Frequently Asked Questions

Is it safe to paste production JWTs here?
Yes. All decoding occurs 100% in your local browser JavaScript engine. No token data, claims, or headers are ever transmitted to any server or logged anywhere.
Does this tool verify token signatures?
This tool inspects and decodes JWT tokens. Signature verification requires your application's private secret key or public certificate, which should never be exposed in a client-side environment.
What do standard JWT claims like exp, iat, and sub mean?
exp represents the expiration Unix timestamp, iat indicates when the token was issued, and sub denotes the subject (often the user or service account ID).

Methodology

Rankings and recommendations here are never paid for.

Last updated .

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