Understanding JWT Tokens: A Developer's Guide
December 27, 2025
JSON Web Tokens (JWT) are a compact, URL-safe means of representing claims to be transferred between two parties.
JWT Structure
A JWT consists of three parts separated by dots: Header, Payload, and Signature.
- Header: Contains token type and algorithm
- Payload: Contains claims (user data)
- Signature: Verifies token integrity
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Never store sensitive data in JWT payloads - they can be decoded by anyone!