Decode JWT Tokens Without Sending Them to JWT.io
JWT.io is the de facto JWT debugging tool — but it loads external scripts and analytics that could capture form data. BigWow parses JWTs using local Base64 URL decoding with zero external scripts, zero analytics, and zero network requests.
0 JWT characters transmitted to any server or API.
Decodes Header, Payload, and Signature parts locally in microseconds.
Checks token expiration timestamps and flags expired sessions locally.
BigWow vs JWT.io — Feature Comparison
| Feature | BigWow | JWT.io |
|---|---|---|
| Token transmitted to server | Never | Runs client-side (verify before use) |
| Third-party scripts | None | Present |
| Works offline | Yes | No |
| Shows expiry warning | Yes | Yes |
| Open source | Yes | Partial |
Frequently Asked Questions
Does JWT.io send my token to their servers?
JWT.io's debugger operates client-side, but their site loads external analytics that could capture clipboard or form data. BigWow has zero analytics and parses entirely locally.
Should I share JWT tokens with any online tool?
No. A JWT carries your authentication credentials. For maximum safety, use a local tool that performs all decoding in your browser without external network calls.
Sources & References
- IETF RFC 7519 JSON Web Token (JWT) specification.
- OWASP Authentication Cheat Sheet warning against sharing session tokens with third parties.
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