Runs locally · No upload
Utillio vs JWT.io — Decode, Verify & Sign Tokens Privately
JWT.io is the industry-standard JWT debugger — great for learning token structure. Utillio matches the decode experience and adds signature verification (HS256 and RS256), expiry badges, and a sign tab — all without sending tokens to a server.
Utillio
- Decode tab — claims table, formatted header/payload, expiry badge
- Verify tab — HS256/384/512 with secret, RS256/384/512 with PEM public key
- Sign tab — create test tokens with custom claims and HMAC secrets
- 100% client-side — production tokens never uploaded or logged
- Shareable links preserve token, tab, algorithm, and key state
- Works offline after page load — no account required
JWT.io
- Industry-standard JWT reference with extensive documentation
- Strong decode and sign experience for learning
- Verify with RSA may require server-side processing on some setups
- High-traffic site — higher exposure if inputs are logged
- Focused on JWT only — no integrated JSON, Base64, or hash tools
Verdict
For learning with public sample tokens, either tool works. For staging or production JWTs, Utillio lets you decode claims, verify RS256 signatures with your public key, and sign test tokens — all locally in one workbench.