---
title: "JWT Decoder | Free DevOps Tool | FOSSA"
description: "Free online JWT decoder and inspector. Decode JSON Web Tokens to understand their contents, claims, and expiration times. Perfect for debugging authentication issues."
canonical_url: "https://fossa.com/resources/devops-tools/jwt-decoder/"
markdown_url: "https://fossa.com/resources/devops-tools/jwt-decoder.md"
language: "en"
author: "FOSSA"
organization: "FOSSA"
---

# JWT Decoder | Free DevOps Tool | FOSSA

> Free online JWT decoder and inspector. Decode JSON Web Tokens to understand their contents, claims, and expiration times. Perfect for debugging authentication issues.

## JWT Decoder

Decode and inspect JSON Web Tokens (JWT) to understand their contents and claims.

### About JWTs

JSON Web Tokens (JWTs) are an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. They are commonly used for authentication and authorization in web applications and APIs.

#### JWT Structure

A JWT consists of three parts separated by dots (.):

- Header \- Contains metadata about the token, such as the type and signing algorithm
- Payload \- Contains the claims (statements about the user) and additional data
- Signature \- Ensures the token hasn't been altered after being issued

#### Common JWT Claims

- `iss` (Issuer) - Who issued the token
- `sub` (Subject) - Who the token refers to
- `aud` (Audience) - Who the token is intended for
- `exp` (Expiration Time) - When the token expires
- `nbf` (Not Before) - When the token starts being valid
- `iat` (Issued At) - When the token was issued
- `jti` (JWT ID) - Unique identifier for the token

#### JWT Security Considerations

- Never store sensitive information in a JWT payload as it can be decoded easily
- Always use HTTPS when transmitting JWTs to prevent token theft
- Set appropriate expiration times for your JWTs to minimize risk if compromised
- Consider using refresh tokens alongside JWTs for better security
- Validate tokens on the server side before trusting the claims they contain

##### Note

This tool only decodes JWTs for inspection and does not verify the cryptographic signature. In production systems, always verify JWT signatures before trusting their contents.

### Get Started with FOSSA

Start managing your dependencies, licenses, and vulnerabilities today.

## Source

Canonical page: https://fossa.com/resources/devops-tools/jwt-decoder/