Webhook tools do three different jobs and the shopping lists barely overlap. Debugging what a provider actually sends: Webhook.site and RequestBin show you the raw request in seconds, free. Receiving reliably — surviving retries, duplicates and your own downtime: Hookdeck and Convoy sit in front of your endpoint as a gateway. Sending webhooks to your own customers, with per-customer endpoints, signing, retry policy and a delivery log: Svix is the managed answer, or you build it. And if the endpoint doing the receiving is an app you're building anyway, Greta generates it with verification, idempotency and a retry-safe handler included, which is the part teams most often skip. Know which of the three jobs you have — buying for the wrong one is the usual mistake.
Webhooks look trivial until the first duplicate delivery charges a customer twice. Almost everything hard about them is delivery semantics, not HTTP.
How we compared
Which job each tool does, what it gives you for retries and replay, whether signature verification is handled or assumed, and cost at low volume. Pricing shapes checked September 2026 — verify live.
At a glance
| Tool | Job | Best for | Pricing shape |
|---|---|---|---|
| Webhook.site | Debug | Seeing the raw payload now | Free; paid for persistence |
| RequestBin | Debug | Same, inspection-focused | Free tier |
| ngrok | Local receipt | Testing against localhost | Free tier; paid tiers |
| Hookdeck | Receive reliably | Queueing, retries, replay | Usage tiers |
| Convoy | Receive/send, open source | Self-hosting the gateway | Free self-hosted; cloud |
| Svix | Send to customers | Being a webhook provider | Usage tiers |
| Greta | Build the endpoint | When the receiver is your app | Free tier; $20/mo ($5 welcome) |
The three jobs
Debugging. You need to see what Stripe or Shopify actually posts. Webhook.site gives you a URL and shows the request — headers, body, timing — with no account. RequestBin does the same with an inspection-first interface. Ninety percent of webhook confusion ends here, for free. Pair either with ngrok when you need the request to reach code running on your laptop.
Receiving reliably. This is where money gets spent and where it is often justified. Providers retry on non-2xx, which means your five minutes of downtime becomes a burst of duplicates later. A gateway like Hookdeck or Convoy accepts the delivery immediately, queues it, retries against your endpoint on your terms, and lets you replay a range after you ship the fix. That last capability — replay — is the one teams discover they needed after an outage.
Sending to your own customers. Being a webhook provider is a product surface: per-customer endpoints, secret rotation, signature schemes, exponential backoff, a delivery log customers can self-serve, and a dashboard when they ask why event 41 never arrived. Svix sells exactly that; Convoy self-hosts it. Building it yourself is a quarter of work that looks like two weeks.
Got an idea? Build it now!
Just start with a simple prompt. No coding required — Greta.sh turns your idea into a working app in minutes.
What no gateway does for you
Whatever you buy, the receiving endpoint still has to be correct, and the correctness lives in three rules: verify the signature before parsing the body (and use the raw bytes — JSON re-serialisation breaks the HMAC), make the handler idempotent on the provider's event id, because duplicates are normal and not an error, and return 2xx fast, doing the real work after acknowledging. A gateway in front of a handler that fails any of the three just delivers the same bug more reliably.
If that endpoint belongs to an app you are building rather than a service you already run, describing it to Greta generates the handler with those rules applied — verification, an idempotency key on the event id, and the queue-then-acknowledge shape — deployed with the rest of the app. Free tier is 30 credits a month (5 a day); $20/month flat after ($5 with the current welcome offer). Our webhooks and third-party APIs guide covers the same ground for apps already in flight, and the duplicate-webhook test is the check worth running before launch.
Plainly: Greta is not a webhook gateway. If you need replay across millions of historical deliveries, buy Hookdeck or Convoy.
FAQ
What is the best free webhook testing tool? Webhook.site for seeing a payload immediately, ngrok when the request needs to reach your local machine. Both are free for the debugging job and neither is meant to sit in production.
Do I need a webhook gateway? If duplicate or missed deliveries would cost money, and you have no way to replay them after an outage, yes. If you receive a handful of low-stakes events, a correct handler is enough.
How do I stop duplicate webhook deliveries causing double charges? You do not stop the duplicates — providers retry by design. You make the handler idempotent: store the provider's event id and make replaying it a no-op.
Should I build my own webhook sending infrastructure? Only if webhooks are a differentiated part of your product. Signing, retries, per-customer secrets, delivery logs and a debugging surface add up to far more than the send loop implies — Svix or Convoy exist because that quarter is real.
