On IFTTT, there are two types of Applets, polling Applets and realtime Applets. Polling Applets use polling triggers, while realtime Applets use realtime triggers.
When you're on a service page, scroll down to see the available Triggers, Queries, and Actions for that service. Triggers will be labeled as either Realtime or Polling, so you can easily identify how they work.
Example of Realtime Triggers on the Camera Widget service page
Polling Applets
Polling Applets run after IFTTT reaches out to the trigger service and finds a new trigger event. These trigger checks occur every 5 minutes for Pro and Pro+ users, and every hour for Free users.
When viewing the Applet's activity feed, the heading Successful trigger checks indicates the Applet is using a polling trigger:
Because of the reactive nature of polling triggers, we expect polling Applets to run within 5 minutes of a trigger event occurring for Pro and Pro+ users, and within one hour for Free users.
Realtime Applets
Realtime Applets run after the trigger service notifies IFTTT of a new trigger event. Since IFTTT is notified proactively of new trigger events, realtime Applets normally run within a few seconds of a trigger event occurring.
When viewing the Applet's activity feed, the heading Listening for trigger notifications indicates the Applet is using a real time trigger:
What determines if a Trigger is Polling or realtime?
Whether a Trigger is polling or realtime depends on how the service creator set up their IFTTT integration. Service owners can update their Triggers to use the IFTTT realtime API, but you can't change this setting yourself when configuring an Applet.
Can I make my Applet run faster?
If an Applet uses a polling Trigger, Pro and Pro+ users benefit from faster polling intervals. Trigger checks occur every 5 minutes for Pro and Pro+ users, compared with every hour for Free users.
If a service offers a realtime Trigger, using it will generally result in the fastest Applet execution.