Compare

Compare picks two captured webhooks and shows you exactly what's different — headers, body, metadata. Critical for debugging "why did this one fail when that one worked?" or spotting schema changes a provider rolled out without telling you.

How It Works

1. Click Compare in the endpoint toolbar — the request list switches to selection mode
2. Click two requests to mark them as A and B (in order of selection)
3. Click View Diff — the comparison opens in a two-pane modal
4. Use the tabs across the top to switch between Meta, Headers, and Body

Comparison Tabs

• Meta — HTTP method, status, content type, payload size, source IP, timestamp, latency, signature verification
• Headers — Every header name and value; missing keys highlighted on the side they're absent from
• Body — JSON-aware structural diff with nested path display (data.customer.id); falls back to text diff for non-JSON

Diff Highlighting

• Green — Present only in B (added)
• Red — Present only in A (removed)
• Yellow — Changed (value differs between A and B)

Toggle Differences only to hide identical fields — most useful for diffing two large payloads where 95% of the body is the same.

Use Cases

• Schema regression detection — diff today's checkout.session.completed against last week's; spot fields a provider added or removed
• Failed vs successful — pick the one your handler accepted and the one it rejected; the diff narrows the bug
• Test vs production parity — diff a request from your test environment against a real one to confirm payload shape matches
• Replay before/after — capture before a code change, replay after, diff the responses

Available on all plans.

Frequently asked

How many replays do I get on the free plan?

5 replays total on Free — that's a lifetime cap until you upgrade, not a monthly reset. Hook, Sense, and Enterprise all include unlimited replays.

Will replaying a webhook trigger duplicate side effects in my handler?

Yes, if your handler isn't idempotent. HookSense re-sends the exact bytes (headers, body, signature) — your handler treats it as a normal incoming request. Production webhook handlers should always be idempotent (use the event ID as a dedup key); replay just makes the idempotency requirement visible.

Can I edit the request before replaying?

Yes. The replay UI lets you change the target URL, override headers (e.g., swap auth tokens for staging), and edit the body. Use Repeat Mode to send the same modified request up to 50 times with a configurable delay — useful for testing rate limits or load behavior on your handler.

Can I replay to localhost?

Two ways. First, install the CLI (npx hooksense listen -p 3000) — it forwards every captured webhook to localhost in real time, and any replay also flows through. Second, in the replay UI, target http://localhost:3000 directly — works as long as the browser can reach localhost.

What's the difference between Replay and Slack/Discord Forwarding?

Replay re-sends the original captured webhook to a target URL on demand (one-shot, manual). Forwarding mirrors every captured webhook into a Slack/Discord channel automatically (continuous, real time). Forwarding is a Sense feature meant for team visibility, not for re-driving your handler.