Decode JWT tokens, inspect headers & payloads, check expiration — all in your browser
Header
Payload
Free JWT decoder and encoder. Decode JWT headers and payloads, check expiration, and create new JWTs with HS256/HS384/HS512 signing. This tool is built for practical, real-world usage where speed, clarity, and reliable output matter. You can start with the default values, review the result, and then refine inputs step by step to match your exact scenario.
For best results, keep your inputs clean and complete. Double-check units, date ranges, and value formats before you calculate. If you are comparing multiple scenarios, change one variable at a time so you can clearly understand what moved the output.
This page helps when you need a quick answer without switching apps, creating accounts, or installing software. It is suitable for professionals, founders, students, and teams who want transparent logic and immediate outputs.
The tool is designed for guidance and operational calculations. For compliance-critical submissions or legal/financial filings, always verify with your official source rules and current regulations. We regularly improve these pages so they remain practical and dependable for day-to-day work.
You can also explore related tools from the full directory at /tools and, where available, automate similar workflows using our API services.
Header: Algorithm and token type. Payload: Claims (user data, expiration, etc.). Signature: Verification hash created with the secret key. Parts are separated by dots.
iat: Issued At (timestamp). exp: Expiration Time. nbf: Not Before. iss: Issuer. sub: Subject. aud: Audience. jti: JWT ID (unique identifier).
HS256 uses a shared secret (symmetric). RS256 uses RSA key pair (asymmetric) — private key signs, public key verifies. RS256 is preferred for distributed systems.
Purpose: Decode JWT headers and payloads, check expiration, and create new JWTs.
Free JWT decoder and encoder. Decode JWT headers and payloads, check expiration, and create new JWTs with HS256/HS384/HS512 signing.
This dev tool page is maintained to help users make better decisions with transparent inputs, reproducible outputs, and practical interpretation guidance.