// septim labs · webhook inspector · browser-only

Your webhook payload never leaves this tab.

RequestBin and Webhook.site log every payload to a server — including Stripe order data, GitHub diffs, and Shopify PII. This tool parses, identifies, and diffs webhook bodies entirely in the browser. Close the tab and it is gone.

client-side  ·  zero network calls  ·  no telemetry  ·  no login

// paste payload

Payload A — parse and identify.

Paste the raw webhook body. The tool auto-detects JSON, application/x-www-form-urlencoded, or raw text. Paste signature headers below for optional HMAC verification — all done in-browser via crypto.subtle.

// payload body
// parsed structure
// payload b
// verify zero network calls

Open DevTools (F12 or Cmd+Option+I), click the Network tab, then paste a payload and click Inspect. No requests fire during parsing or diffing. HMAC verification uses crypto.subtle.importKey and crypto.subtle.verify — the browser's built-in cryptographic engine, which never sends data over the network. Your payload stays in your browser tab.

// why this matters

The browser's crypto engine is already fast enough.

HMAC verification uses crypto.subtle — the same engine your browser runs for TLS. Stripe signature verification, GitHub sha256= headers, Svix v1, — all checked locally in under a millisecond. No secret leaves the input field.

// if you're debugging Stripe webhook failures

Webhook fires. Handler crashes. Payment not recorded. Dunning email never sends. That loop is a bug you shipped. Septim Tether catches it at pre-commit — malformed event shapes, missing idempotency keys, unhandled status codes — before it costs a customer. $19 once.

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