JWT Explained: What's Actually Inside a JSON Web Token

📰 Dev.to · Sven Schuchardt

Learn what's inside a JSON Web Token and how to work with it in API integrations

intermediate Published 10 Apr 2026
Action Steps
  1. Decode a JWT token using a tool like jwt.io to reveal its contents
  2. Verify the token's signature to ensure its authenticity
  3. Extract the payload from the token to access user data or claims
  4. Use a library like jsonwebtoken in Node.js to generate and verify JWT tokens
  5. Test JWT token validation in your API integration using tools like Postman
Who Needs to Know This

Developers and engineers working with APIs and authentication systems can benefit from understanding JSON Web Tokens

Key Insight

💡 A JSON Web Token consists of three parts: header, payload, and signature, which can be decoded and verified for authentication purposes

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🔓 Unlock the secrets of JSON Web Tokens! Learn what's inside and how to work with them in API integrations

Key Takeaways

Learn what's inside a JSON Web Token and how to work with it in API integrations

Full Article

You're integrating an API and you get back a token that starts with eyJ. You paste it somewhere and...
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