Decode your JWT (JSON Web Tokens) instantly with this free and secure web tool from CodeTap. Just paste your token to view its contents—header, payload, and signature—clearly formatted and without storing or transmitting any data.
A JWT (JSON Web Token) is a compact, URL-safe token format used for authentication and data exchange in modern web applications. It’s composed of three parts:
Header – Algorithm and token type (e.g., HS256, RS256)
Payload – The data or claims being transmitted
Signature – Ensures integrity and authenticity
🧩 Instant Token Decoding: View header, payload, and signature
🔐 Privacy-Safe: No token is sent to the server
🎨 Syntax Highlighting: Clean, easy-to-read formatting
📎 Copy-to-Clipboard: Copy decoded parts with one click
🧪 Works with HS256, RS256 & more: No algorithm restriction
⚡ Lightning Fast: Decoding happens in your browser
Web developers working with secure APIs
Backend engineers validating auth flows
Security testers inspecting token integrity
Students learning JWT format and structure
Anyone curious about how JWTs work
Decode and inspect a token for debugging
Understand what user data is being passed
Troubleshoot token expiration or invalid claims
Educate yourself or your team on JWT structure
Verify if a token was tampered with (manually)
🔒 100% client-side decoding – nothing leaves your browser
🧠 No signup, no limits, no ads
🎯 Lightweight and developer-focused
🔧 Built by devs who care about privacy and performance
A JWT (JSON Web Token) is a compact, URL-safe token used to securely transmit data between parties. It consists of three parts: Header, Payload, and Signature, separated by dots (.).
This tool decodes JWT tokens and displays the header, payload, and signature in a readable format. It helps developers inspect the contents of a token without verifying its signature.
No. Decoding only reveals the data inside the token—it does not prove that the token is valid or secure. To verify a JWT, you need the secret key or public key used to sign it.
Yes, if the tool runs entirely in your browser (client-side). Your JWT never leaves your device. However, avoid decoding highly sensitive tokens on public or shared computers.
A decoded JWT may include:
Header: Token type (JWT), signing algorithm (e.g., HS256)
Payload: Claims like iss (issuer), sub (subject), exp (expiration), email, user_id, etc.
Signature: Used to verify the token’s authenticity (not human-readable)