Are webhooks free?
Yes. A webhook is an HTTP POST to a URL, so there is no license, no protocol fee, and no SDK you have to buy. Providers like Stripe, GitHub, Shopify, Slack, and Discord include webhooks in every plan at no extra charge. What costs money is running the delivery side yourself.
Receiving webhooks costs almost nothing
If you are consuming someone else's webhooks, the bill is whatever the server you already run costs. You add one HTTPS route, verify the signature with an HMAC comparison that takes microseconds, write the event somewhere durable, and return a 2xx quickly. A small VM or a serverless function handles thousands of events a day inside a free or near-free tier.
The work that is not free is correctness. Deliveries are at-least-once, so your handler needs to be idempotent or you will process the same payment twice. You also need somewhere to put events you cannot process yet, because doing the real work inline is what turns a webhook into a timeout and then into a retry storm. That is engineering time rather than a line item, but it is the part teams underestimate.
Sending webhooks is where the cost shows up
Sending looks equally free at the start. Your service already has the event, an HTTP client is three lines, and the first version ships in an afternoon. The expense arrives with the second year of running it, and it is mostly infrastructure that has nothing to do with your product:
- Queue workers that can absorb a burst without blocking the request that produced the event
- Retries with exponential backoff, which means a scheduler and state per attempt
- A dead letter queue and a way to replay from it
- Delivery logs, retained long enough that support can answer "did you send it?", which is the storage line on your cloud bill
- A proxy or allowlist that stops customer-supplied URLs from reaching internal services, since a webhook sender is an SSRF engine by design
- A portal where customers add endpoints, see failures, and rotate secrets without filing a ticket
The webhook infrastructure page walks through the same list in more depth, and how to build a webhook sender is the implementation view of it. None of those pieces is hard on its own. Together they are a service with an on-call rotation.
What managed providers actually charge for
Providers of webhook delivery price by volume, usually events or messages sent per month, and most publish a free or low-volume tier that covers a side project or a pilot. When you compare them, the number to look at is rarely the headline price. Check how long delivery logs are retained, whether replay and a customer-facing portal are included or sold separately, what the per-endpoint rate limits are, and what happens to pricing when one large customer subscribes to every event type you emit.
Testing tools follow the same pattern. Svix Play gives you a URL that shows exactly what your service is sending, for free, and the webhook testing guide and our roundup of testing and debugging tools cover the rest of the free options. The Standard Webhooks specification is open and free to implement, so the signature scheme itself never has to be a purchase decision.
The question underneath
People asking whether webhooks are free are usually deciding whether to build sending themselves. The honest arithmetic is that the protocol is free, the first implementation is cheap, and the ongoing operation is not: rate limits, endpoint outages, secret rotation, and support tickets about duplicate events do not stop arriving. Weigh that engineering time against a per-event price rather than comparing a paid service to zero.
If you are consuming webhooks, build the endpoint and pay nobody. If you are sending them to customers, Svix runs the delivery layer described above so the cost is a bill instead of a team, and why webhooks as a service makes the longer case.