What is a Webhook?

Quick Hits 

• A webhook is a web-based application that sends information to other applications when triggered by events.  
• Webhooks differ from APIs because they send information as soon as it’s available, instead of needing to be requested.

If you’re looking for a simple and light solution to send information between applications, webhooks may be the tool you’re looking for.  

What are Webhooks? 

Webhooks are an alternative to APIs and are used to send information between applications over the web. While APIs send requests for data, Webhooks send data as soon as it is needed. Because data is sent as soon as it’s triggered, they are used to send real-time updates between applications.

Also known as an HTTP Push API, webhooks are a resource-light way to send data when triggered by an event.

Webhooks automatically send information as soon as it’s available. APIs poll for information, sending requests for information until the information is available. Another way to think about polling is like a waiter popping up every 30 seconds to see if you’re ready to order. They’ll keep checking until you give them the information they need to set your meal into motion. 

Webhooks, on the other hand, are similar to mobile ordering your meal. As soon as you know what you want, the information is sent, and your meal preparation is (hopefully) started. You can even send information before you arrive at the restaurant.  

While you may enjoy having human interaction in a restaurant situation, there’s a streamlined efficiency to sending information as soon as the information is present to send along.  

How do Webhooks work? 

Webhooks work like push notifications for applications, sending information in real-time over the web. Much like automated text messages, information is sent automatically sent when an event happens. However, instead of sending the information to a phone number, the information is sent to a certain URL.  

Webhooks work by making HTTP GET requests, which sends data to a unique URL and then pings the URL. As soon as an event is detected, the HTTP push API is triggered to send a predefined set of information along to the predefined URL.

Webhooks only work to send information to other applications. If there is anything you want this information to be used for, you must design an API for the webhook site to use. APIs can use the information they receive to trigger additional functionalities.  

For example, a webhook may be triggered by a purchase being completed. The purchase is an event that triggers the transfer of information about the purchase to an API over the web. Once the API has the information, it can then send an email receipt, print the order label, or perform any other function that needs to be started because of the order.  

Webhook vs API

Both APIs and webhooks share data between applications. In order to connect applications, it is important to decide the right tool for the function needed.  

An API enables two-way communication to connect applications.  APIs are essentially a selection of usable operations for developers, many of which are used to ferry information from one source into another source. APIs connect software to help them share both information and functionality. The Google Maps API, for example, takes information from Google Maps and plugs it into a website using a Google Maps API.

A webhook, on the other hand, enables one-way communication when events trigger information to be sent. Usually this information is needed in order to support an API’s functionality. You can think of them as simple push APIs, made to communicate very specific information. The only real difference is that they send data without it having to be polled.

APIs and webhooks are often used together to simply share data with an API, which can then use the data to trigger additional functionalities. 

Whether you choose to use a webhook or an API to send information between applications largely depends on the information being sent and the speed at which that data needs to be sent. If you need to communicate more complex information, like map data, using an API will likely be the right fit. If the data is simple, then a webhook is a lighter option that can send data as soon as it’s needed.

If you’re sending sensitive data, whether through a webhook or an API, also consider how to secure it as it travels over the web. Check out our tokenization tools to learn more about securing data in transit.