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omegatools
Developer Tools 100% Client-Side Privacy

Free Online JWT Decoder (Inspect Token Claims & Expiration)

Safely decode and inspect JSON Web Tokens. Verify expiration dates, subject, issuer, and custom claims client-side without exposing secrets to any external server.

100% Client-Side Inspection Notice

Decoding a JWT decodes Base64Url payload claims in your browser. Decoding is NOT cryptographic signature verification. A decoded token can still be expired, altered, or forged without verifying the secret key.

How to Use This Tool

How to Use This Tool – JWT Decoder

01

Paste JWT Token

Paste any JSON Web Token (header.payload.signature) into the input box.

02

Inspect Decoded Header & Claims

Review formatted JSON showing algorithm, token expiration, subject, and custom claims.

03

Verify Expiration & Timestamps

Check human-readable expiration dates (exp), issued-at (iat), and not-before (nbf) timings.

Key Features & Capabilities

Key Features & Capabilities – JWT Decoder

Zero Token Leakage

Crucial for security: your secret authentication tokens are never sent to external servers.

Color-Coded Token Highlighting

Visual separation between Header (red), Payload (purple), and Signature (blue).

Automatic Expiration Status

Calculates active vs expired token status with exact countdown and readable UTC times.

JSON Beautifier & Copy

One-click copy for decoded payload claims formatted in standard 2-space JSON.

FAQ

Frequently Asked Questions

Is it safe to decode production tokens here?
Yes! Unlike cloud token inspectors, OmegaTools decodes JWTs 100% locally in your browser using base64 decoding.
Does this tool verify token signatures?
This tool inspects and validates header and payload structures. Secret keys are not required for client-side decoding.
What formats are supported?
All standard RFC 7519 JWT tokens encoded with Base64URL.
Can I decode expired tokens?
Yes, expired tokens are decoded and flagged with their exact expiration timestamp.
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