developer Overview
JWT, OAuth PKCE & TOTP Auth StudioFree onlineNo sign-upNo upload
Inspect JWT Headers, Payload Claims & HMAC Signatures Privately
Paste any JSON Web Token into JWT Auth Studio to inspect decoded JOSE headers, verify `exp`/`nbf`/`iat` validity windows, check HS256/HS384/HS512 signatures via SubtleCrypto, and generate OAuth 2.0 PKCE S256 challenges.
Open the free JWT, OAuth PKCE & TOTP Auth Studio
No account required · Runs in your browser · Instant results
JWT, OAuth PKCE & TOTP Auth Studio — jwt decoder and hmac verifier
Because JWT Studio performs zero network calls and fetches no remote endpoints, staging bearer tokens and test signing secrets stay isolated inside your local browser tab.
Quick tip: Remember that standard JWS payloads are Base64URL-encoded—never place unencrypted secrets inside public JWT claims.
Frequently asked questions
Can JWT Studio generate OAuth 2.0 PKCE code_verifier and code_challenge pairs?
Yes. Switch to the PKCE & Auth Helpers tab to generate cryptographic S256 verifier/challenge pairs instantly.
Use the full JWT, OAuth PKCE & TOTP Auth Studio
Access all features of the JWT, OAuth PKCE & TOTP Auth Studio — free, browser-based, no account required.
Open JWT, OAuth PKCE & TOTP Auth StudioYou might also need
Hash, Bcrypt, AES & Keypair Studio
Compute MD5/SHA-1/256/384/512 text & file checksums, sign HMACs, benchmark & verify bcrypt hashes, encrypt with PBKDF2 AES-256-GCM, and generate RSA-OAEP/ECDSA PEM & JWK keypairs.
Encoding, URL & Unicode Studio
UTF-8 Base64 & Base64URL encoder/decoder, local file Data URI builder, interactive URL & query-param editor, HTML entity/JSON string escaper, and Unicode/Hex/Binary byte inspector.