How to Decode a JWT Token Online — JWT Decoder Tool Guide

What Is a JWT?

A JSON Web Token (JWT) is a compact, URL-safe token used for authentication and information exchange in web applications. It consists of three Base64url-encoded parts separated by dots:

header.payload.signature

JWT Structure:

• Header: Algorithm and token type (e.g., HS256)
• Payload: Claims — user ID, expiry, roles, permissions
• Signature: Verifies the token hasn't been tampered with

Decode a JWT Instantly

Our JWT Decoder parses any JWT and displays the header and payload in readable JSON format — no backend, no API key, no signup.

1. Paste your JWT token (the full eyJ... string)

2. See the decoded header and payload

3. Check expiry time, user ID, and all claims

4. Verify the token structure

→ [Decode a JWT Now — Free](/web-developer-tools/jwt-decoder)

Important: Decoding vs Verification

⚠️ Decoding a JWT is not the same as verifying it. Anyone can decode a JWT to read its claims. Only a server with the secret key can verify the signature.

This tool is safe for:

• ✅ Reading token contents during development
• ✅ Debugging expired tokens
• ✅ Checking what claims are included

This tool should NOT be used for:

• ❌ Verifying if a token is legitimate (do this server-side)
• ❌ Trusting the claims without signature verification

Related Developer Tools

• Base64 Decoder — JWTs use Base64url encoding
• JSON Formatter — format decoded JSON payloads
• URL Encoder — JWTs are URL-safe