Local-First JWT.io Alternative for Token Inspection & Verification
Inspecting production or staging bearer tokens requires strict local execution so live credentials never leak through telemetry or shared URLs. JWT & Auth Token Studio decodes JOSE headers and claim payloads, checks expiration windows, and verifies HMAC signatures via native SubtleCrypto.
Try the free JWT & Auth Token Studio now
No account required · Runs in your browser · Instant results
JWT.io vs thefreeaitools.com — feature comparison
| Feature | JWT.io | thefreeaitools.com |
|---|---|---|
| Token decoding & claim audit | Client-side debugger | Local header, payload & exp/iat/nbf audit |
| HMAC signing & verification | HS256/384/512 | Native Web Crypto HS256/384/512 |
| OAuth PKCE & TOTP helpers | Separate tools | Integrated PKCE S256 & TOTP workspace |
Why choose thefreeaitools.com over JWT.io?
Human-readable claim timestamps
Automatically translates Unix exp, nbf, and iat integers into UTC and local timestamps with expiry badges.
All-in-one auth debugging
Generate OAuth 2.0 PKCE code_verifier / code_challenge pairs in the same studio.
Never paste active production secrets into untrusted websites; our studio executes SubtleCrypto checks strictly in local tab memory.
Frequently asked questions
Does JWT Studio fetch remote JWKS keys over the network?
No. To guarantee zero outbound traffic, verification runs locally against secrets or keys you provide.
Decode JWT headers & OIDC claims locally, verify and mint HS256/384/512 tokens via Web Crypto, generate OAuth 2.0 PKCE S256 challenges, and test RFC 6238 TOTP 2FA codes.
- Permanently free — no plans or tiers
- No account or sign-up required
- Runs entirely in your browser
- Files never leave your device