A trigger is an event within an app that starts a Zap. Once you’ve turned your Zap on, Zapier will check for that trigger event. Zaps can be triggered in two ways: through a regular polling event, or instantly through webhooks.
Each app on Zapier has an API that allows other apps, like Zapier, to view and edit its data. Each trigger on Zapier connects to that app’s API to get new data about trigger events.
A trigger event is the data that the trigger is meant to receive, such as a new lead, or a new subscriber on a list.
Most APIs require apps to ask for new data periodically. This is called polling for new data. In Zapier, polling triggers ask the API for all recent data. It then uses a process called deduplication to check if any of that data is new. If it is, the Zap runs. If not, it waits for a set period, then asks again, and so on.
Some APIs automatically send new data as those trigger events occur, using webhooks. These are called "instant" triggers. In Zapier, instant triggers wait for the app to send new data automatically. Zapier does not have to ask the API if there’s any new data. When it receives new data, the Zap runs.
The type of trigger is defined by each app’s API. Some apps support polling triggers, others support instant triggers, and some support both.
- You cannot change a trigger's type.
- The trigger type is defined by the app’s API.
- Most APIs provide ways to poll for data.
- To use instant triggers, an app must offer webhooks, which send new data to a Zap automatically without polling.
- Zaps will only trigger for new data.
- It will not trigger for old data, including data that was created in your app before the Zap was turned on.
- If you need to transfer existing data, use Zapier’s Transfer feature.
The majority of triggers are polling triggers. They check (or poll) the app for data at regular intervals. The Zap will check if there's new data by comparing the item's unique ID to IDs it's already received before.
The interval it uses to check for data depends on your Zapier plan. The shorter the interval, the faster new data will come through the Zap.
Users on Company plans can change how often their polling triggers poll for new data.
Instant triggers work by using webhooks. Webhooks are automated notifications sent between apps. Whenever there is new data, the app will notify Zapier as soon as that data is added in the app.
Zaps with instant triggers are labeled "Instant" on your dashboard and in the Zap editor.
Testing triggers to return test records
When you test a trigger while editing a Zap, Zapier will attempt to find a recent item from your trigger app that you can use as a test record to build your Zap.
When you test a polling trigger, Zapier will:
- Poll the app for data.
- Display the three most recent trigger items found in the poll.
When you test an instant trigger, Zapier will:
- Begin listening for new data from your app.
- Display up to three of the most recent trigger items that were created after Zapier begins listening for new data from your app.
For instant triggers, Zapier can only load test records for data that was created in your app after you first open the Test section in your trigger step.
Learn more about how to set up a Zap trigger.