As modern web development evolves, the desire to communicate effectively with people sets a large precedent. To meet the communication demand of technology, we need to find a way to make technologies talk to each other. That’s where APIs and webhooks come into the picture.
Both webhooks and APIs enable syncing and relaying data between two applications. However, both have different modus operandi and thus serve slightly different purposes. To clear up any confusion between the two, let’s take a look at the differences between a webhook and an API and what kind of scenario each one is most appropriate.
API vs Webhook: The Difference in Clear Terms
API stands for Application Programming Interface, which is a software intermediary that allows two applications to talk to each other. In other words, an API is a messenger that delivers your request to the provider that you're requesting it from and then delivers the response back to you. On the other hand, Webhook, also called reverse API, web callback, or an HTTP push API is a way for an app to provide other applications with real-time information. It delivers data as an event happens or almost immediately.
APIs are request-based, meaning that they operate when requests come from 3rd party apps. Webhooks are event-based, meaning that they will run when a specific event occurs in the source app.
To use a real-world analogy, APIs would be likened to you repeatedly calling a retailer to ask if they’ve stocked up on a brand of shoes you like. Webhooks would then be like asking the retailer to call you whenever they have the shoes in stock, which frees up time on both sides.
Webhooks are less resource-intensive because they save you time on constantly polling (checking) for new data.
The main difference between them is that webhooks do not need to give a request to get a response while API demands requests to get a response. In other words, webhooks receive, while API retrieves.
What is the definition of a Webhook?
Webhooks are one way that apps can send automated messages or information to other apps. It's how Twilio routes SMS and phone calls to your number, how WooCommerce can notify you about new orders in Slack, MailChimp uses a webhook to signup users from your website to your newsletter.
They're a simple way your online accounts can interact with each other and get notified automatically when an event occurs. In many cases, you'll need to know how to use webhooks if you want to push data from one app to another. Webhooks make real-time very simple.
What is an API, exactly?
API is not event-based they are request-based. Whenever we submit a form or make a post or a comment on Twitter or any social platform, we're sending data from the client-side to the server down to the database. API’s are triggered by requests, whether you’re sending data or you are requesting data.
You could have an API that Creates, Reads, Updates, or Deletes data based on a request. For Api’s, the request begets a response.
Although real-time is possible with API, it requires an extra configuration, which then makes webhooks the most suitable mechanism for real-time information.
When to Use Webhooks
Webhooks usually act as a messenger for smaller data. It helps to send and extracting real-time updates.
One of the most suitable scenarios for using a webhook is when your app or platform requires a real-time feature and you don’t want to use an API, because you don’t want to get entangled with the setups and waste resources in the process. In such instances, a webhook framework will be most beneficial.
Another best use case for using a webhook is where an API isn’t provided or the available API isn’t best fit to act, a webhook could be used instead in such a situation.
Webhooks can be regarded as a perfect, and sometimes even essential complement to API-based application integration.
Here are some outlines from Agility CMS on other use cases of using a webhook:
- Clearing and managing a custom cache in an external system such as a website, mobile application, or database.
- Providing a way to sync content/data for integrations with third-party systems (i.e. Salesforce, Mailchimp, etc).
- Building custom content workflows.
- Kick off a CI/D pipeline to redeploy your website when content has been updated - this is often used for JAMstack sites that are built using static site generators.
Content Webhooks allow external applications or websites to become aware of content changes that occur within your Agility CMS instance.
It works by providing a list or URL endpoints to Agility CMS. Each time content changes or is published in the CMS, Agility will notify each endpoint of the change and pass-on a message representing the exact change that occurred.
To get started with a webhook on Agility CMS, follow this guide.
When To Use APIs
APIs work incredibly well when you’re certain of constant incremental changes in data. Relatively stagnate data doesn’t need an API. For example, if you’re an eCommerce store that regularly has to track data or updating some shipping status, then an API would be the best bet.
As you know, to obtain data updates through API, you need to “call” it regularly. So, one can say that APIs are a great fit for application integration when you know you will have a constant change of data.
APIs are still popular for several reasons:
- Not every application supports webhook integrations.
- Sometimes you only want to know about the result, rather than every event (i.e. every permutation) that’s changed an object.
- Webhooks can only notify you about an event, so if you want to make a change based on new information, you’ll need an API.
- A webhook payload may not contain all the data you need about an event, hence an API is used.
Both APIs and webhooks have different use cases, but if your goal is to transfer data between two services, webhooks are the way to go. However, if your platform or application would demand frequent data changes, then an API should be used.
You could use both APIs and webhooks together to create a system that can communicate the right types of data as it suits your application.
About the Author
Blessing Krofegha is a fullstack Software Developer, and Technical Writer. He is well experienced in writing API documentation, as well as building APIs, using logging and ARM tools like New Relic, etc. He is a prolific Technical writer for Companies and Publications like Smashing Magazine, logRocket and also has a track record in helping many developer communities in his locality to organize and plan events.