JWT decoder, verifier and encoder
Inspect JWT JSON, verify an HS256 signature or create an HS256 token with a secret that never leaves this browser.
Security note: Decoding only reads the token; it does not verify its signature or trust its claims. Avoid real production secrets on shared devices.
Use JWTs safely
The header and payload are readable claims; only trusted server-side signature and claim validation can establish whether a token should be accepted.
Read the JWT safety guide for claims, HS256 secrets and complete validation checks.