Guides
Step-by-step tutorials for JWT authentication, secret generation, token validation, and cryptographic utilities. Each guide links to our free browser tools and includes copy-paste code examples.
Language-specific guides cover Node.js, Python, Go, Java, and Ruby. For definitions, see the glossary. For algorithm decisions, see algorithm pages.
Try JWT Secret Generator — open toolQuickstart Guides
Generate a JWT Secret in 5 Minutes
Generate a cryptographically secure HS256 JWT secret in your browser, store it safely, and sign your first token in under five minutes.
Validate a JWT Token — Quickstart
Verify JWT signatures, check expiration, and validate iss/aud claims with an explicit algorithm allowlist — plus our free browser JWT Validator for debugging.
Store JWT Secrets — Security Checklist
Checklist for storing JWT secrets safely: local .env hygiene, production secrets managers, environment separation, rotation planning, and what never to do.
Rotate JWT Secrets Without Downtime
Rotate HS256 JWT signing secrets with kid-based dual verification so existing tokens keep working until they expire — zero forced logout when planned well.
Decode a JWT Safely (Without Trusting It)
Decode JWT header and payload for debugging without treating decode as authentication. Always verify signatures with an allowlist before authorizing requests.
Choose HS256 or RS256 for Your API
Decide between HS256 shared secrets and RS256 public/private keys for your API. Quick decision steps plus links to full side-by-side algorithm comparisons.
JWT Claims Checklist (iss, aud, exp, nbf)
Production checklist for JWT registered claims: exp, nbf, iss, aud, and sub — plus how to validate them with our free JWT Validator.
Sign Your First RS256 JWT
Generate an RSA key pair in your browser, sign an RS256 JWT, and verify it with the public key — a practical RS256 quickstart for APIs.
Fix Invalid Signature JWT Errors
Debug JWT invalid signature failures step by step: wrong secret, algorithm mismatch, whitespace in env values, and kid rotation issues — with our free JWT Validator.