Free, browser-based utilities for everyday developer workflows

Security and debugging tools

Inspect, verify and sanitize sensitive API debugging data locally in your browser. Use these tools before sharing HAR files, debugging webhook signatures, decoding JWTs or inspecting certificates — the data never leaves your machine.

Which security/debugging tool should I use?

Common security/debugging problems

  • Sanitize browser network logs before sending to vendor support
  • Check whether HAR files contain cookies or bearer tokens
  • Verify webhook payload signatures
  • Decode JWT claims during API debugging
  • Convert JWKS keys for backend validation
  • Inspect certificate expiration and subject details

Practical guides

FAQ

Should I sanitize a HAR file before sharing it?

Yes. HAR files captured from browser DevTools usually contain cookies, Authorization headers, bearer tokens, API keys and full request bodies. Redact them with the HAR Sanitizer before sending the file to a vendor or support team.

Can a HAR file contain cookies or tokens?

Yes. A HAR is a full record of network traffic, so it can include Cookie and Set-Cookie headers, Authorization headers, bearer and session tokens, API keys in query strings and sensitive payloads. See what a HAR file can contain.

Can I decode a JWT locally?

Yes. The JWT Decoder parses the header and payload claims in your browser so you can inspect issuer, audience, expiry and custom claims without sending the token anywhere.

How do I verify webhook signatures?

Use the Webhook Signature Verifier. Paste the raw payload, the signing secret and the signature header to recompute the HMAC and confirm a Stripe, GitHub, Slack or custom signature matches.

What is the difference between JWK, JWKS and PEM?

A JWK is a single key in JSON form. A JWKS is a JSON set of multiple JWKs, typically served at a /.well-known/jwks.json endpoint. PEM is the Base64 ASCII format used by most backend libraries. The JWK/JWKS/PEM Converter translates a public key between these formats.

Is sensitive data uploaded to a server?

No. Every tool in this cluster runs locally in your browser. HAR files, tokens, keys and certificates are processed in memory and are not sent to a server or logged.

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