APIs vs Webhooks: Understanding the Difference for Zapier and Make Automation

A practical field guide from Automation Ace.

APIs vs Webhooks: Understanding the Difference for Zapier and Make Automation

APIs and webhooks are both ways for software systems to communicate, but they work in opposite directions. For a plain-English explanation of how webhooks specifically work, see what is a webhook. For the Zapier-specific question of polling vs. instant triggers, see Zapier polling triggers vs. instant triggers. An API call is your automation tool reaching out to an app and asking for data or requesting an action. A webhook is an app reaching out to your automation tool to report that something happened. Both are essential building blocks of modern workflow automation — and understanding the difference determines which tool you reach for in any given situation.

The confusion between the two is understandable because both involve HTTP requests and JSON data. The key distinction is who initiates the communication. With an API call, your Zap or Make scenario is the requester — it sends a request and waits for a response. With a webhook, the source app is the initiator — it sends a notification to a URL you provide, and your automation receives and processes it. One is request-response; the other is event-notification.

APIs: How Zapier Uses Them Behind the Scenes

Every action step in Zapier — "Create Contact in HubSpot," "Send Message in Slack," "Update Row in Google Sheets" — is an API call. When you map fields in the Zap editor and run a test, Zapier sends a structured HTTP request to the target app's API using your connected account credentials. The app processes the request, performs the action, and returns a response confirming success or describing an error. This happens automatically; you never write the API request yourself when using a built-in Zapier integration.

When Zapier does not have a native integration for an app, you can make API calls directly using the "Webhooks by Zapier" action with GET, POST, PUT, or DELETE method options, or using the "Code by Zapier" step to write a JavaScript or Python fetch. This unlocks integrations with any app that has an API, even if Zapier does not have a dedicated connector for it. See the deeper dive in the article on webhook and API integration consulting for real-world examples.

Webhooks: When Apps Push Data to You

Webhooks reverse the communication direction. Instead of Zapier calling the app, the app calls Zapier. You configure this by providing the app with a webhook URL — a unique endpoint Zapier generates for your Zap. Whenever the specified event occurs in the app (a payment succeeds, a form is submitted, a deal is closed), the app immediately sends a POST request to that URL carrying the event data as JSON.

From a Zapier perspective, the "Webhooks by Zapier" Catch Hook trigger is how you receive incoming webhooks. You generate the URL, paste it into the source app, wait for a test event, and Zapier shows you the received data. From that point, the webhook trigger behaves like any other trigger — you map fields from the received payload into your downstream action steps. The same pattern applies in Make.com, where a "Custom Webhook" module serves the same purpose and is arguably even more flexible in how it handles complex nested JSON payloads.

For a step-by-step decision framework, see API vs webhook: when to use each, and for the capabilities unique to each, read what APIs can do that webhooks can't and what webhooks can do that APIs can't.

When to Use Each Approach

• Use API actions (built-in integrations): whenever you want to create, update, retrieve, or delete data in an app as part of a workflow. This is the default mode in Zapier — the vast majority of Zap action steps are API calls under the hood.
• Use webhooks as triggers: when the source app supports outgoing webhooks and you need near-instant trigger response. Check for the lightning bolt icon in the Zapier trigger list, or use "Webhooks by Zapier — Catch Hook" for apps that do not have native Zapier integrations but can send webhooks.
• Use API calls directly (Webhooks by Zapier or Code steps): when you need to call an API endpoint that Zapier does not expose through its built-in integration, or when you need custom request headers, authentication schemes, or complex request bodies.
• Use webhooks as actions: to send data from a Zap to an external system that accepts incoming webhooks. "Webhooks by Zapier — POST" sends a request to any URL you specify — useful for notifying custom apps, calling internal APIs, or triggering other automation tools.

Think of an API as a telephone call — you dial, you ask, you get an answer. Think of a webhook as a text message notification — the other party messages you the moment something happens, without you having to ask.

Combining APIs and Webhooks in the Same Workflow

Many production workflows use both. A common pattern: a webhook trigger fires when a payment succeeds in Stripe (event push → Zapier receives it), then Zapier makes API calls to create a client record in HubSpot (outgoing API call), send a Slack notification (outgoing API call), and create a project in Asana (outgoing API call). The trigger is webhook-based (instant, event-driven); the actions are API calls (request-response). This is how most well-designed automation workflows operate. Understanding where each technology fits makes you a significantly more capable automation builder. If you need help designing a workflow that involves direct API integration, talk to Automation Ace — these projects often involve authentication complexity and data mapping that benefits from experienced guidance.