13 API integration tools to consider using in 2024

As you look to integrate your applications with application programming interfaces (APIs), you’ll have a host of solutions to choose from.

The solution you should choose depends on the specific integration scenarios you care about, the applications you use, your target audience, among other variables. And while there’s no replacing your own research and evaluation process with specific vendors, we’ll help point you in the right direction by breaking down several vendors that may be worth considering.

To get us started, let’s briefly align on the definitions of API integration and API integration tools, and cover why you’d need an API integration tool to begin with.

What is API integration?

It’s the process of connecting applications through their APIs. Once connected, the applications can sync specific data in near real-time or in predefined, time-based intervals. 

API integration can apply to two scenarios: connecting the applications your organization uses internally and connecting the 3rd-party applications your prospects and clients use with your product.

The two different scenarios of API integration

Related: Examples of API integration

What is an API integration tool?

It’s simply a 3rd-party solution that lets you build and maintain API integrations between your internal applications or between 3rd-party applications and your product.

Why you should use an API integration tool

It ultimately comes down to scalability, resource optimization, and risk management.

Allows your team to scale your integrations

Building, managing, and maintaining integrations is an extremely time-intensive undertaking for your engineers. 

For example, in the case of building integrations, your developers need to follow a specific set of steps for each 3rd-party API they want to build to. This includes researching the relevant endpoints through the provider’s API documentation, building to that endpoint via custom code, and testing the connection through several methods. Considering that your engineers likely need to follow this process for dozens, if not hundreds, of integrations over time, their ability to build a high volume of integrations quickly is compromised. 

API integration tools can help minimize your engineers’ workload in various ways, whether that’s providing pre-built application connectors, a unified API that lets you only build once to access hundreds of integrations, etc. 

Enables your engineers to focus on your core product

While integrations are critical to your business, your engineers aren’t uniquely positioned to build them effectively. They are, however, uniquely positioned to build your core product, whether that’s fixing bugs, enhancing existing features, building out new features, and so on. 

API integration tools allow your engineers to focus less on the former and more on the latter, all but ensuring that your product continues to improve in meaningful ways over time. 

As a side benefit, your engineers will likely be happier at work. Integration projects are often cumbersome and boring, so keeping them focused on your core product should prevent them from burning out and leaving as quickly.

Minimizes your reliance on a select group of engineers

For each integration you build in-house, you’re likely relying on just a handful (maybe even one) of engineers to build and maintain it. As a result, if any of these engineers leave, they can take invaluable information on the integration they worked on with them. This leaves you vulnerable when the integration they worked on breaks or needs to improve, as the remaining team simply might not know what to do.

Since integration tools can help your engineers view any integration in a central location as well as understand how it was built and how it can be fixed/improved upon, you’re less reliant on individual integration engineers. 

Examples of API integration tools

Given that API integration tools can apply to both internal and customer-facing use cases, let’s break down the tools you can find within each category:

API integration tools for internal use cases


The tool, which falls in the category of an integration software as a service (iSaaS), lets you integrate applications and automate fairly simple tasks via “Zaps”. 

The platform is fairly accessible and is often leveraged by teams outside of engineering and IT, such as marketing and sales. However, this can easily introduce security risks to your organization. Moreover, Zapier often lacks the ability to automate more complex processes end-to-end, like quote to cash.


The integration platform as a service (iPaaS) solution lets you integrate your applications, databases, and on-prem systems and automate processes across them. 

Workato generally lets you automate more complex processes than Zapier. It also provides more enterprise-grade security controls to help keep your data protected. That said, the platform requires more technical expertise to use than Zapier, which can prevent many, if not most, of your employees from using it.


Like Workato, the tool is categorized as an iPaaS. It offers similar functionality and capabilities to Workato, but there’s slight notable differences. The platform is, for many, more technically-difficult to use than Workato, and its automation capabilities aren’t as powerful. On the flip side, the tool is now part of Salesforce, and the CRM behemoth has been investing heavily in the platform—especially in its integration capabilities with Salesforce’s other products.


The iPaaS solution has been in the integration space for multiple decades at this point (they were founded in 2000). Similar to Mulesoft, the platform requires more technical expertise to use than Workato and Zapier. That said, countless large companies have adopted the platform—including the likes of Chevron, AT&T, and American Express. 

Part of the reason they’ve done so well with this segment of companies is likely due to the fact that they’ve been around for multiple decades. This has naturally given them more time to win larger accounts and it's likely helped them foster trust with enterprise organizations—as these organizations can confidently assume that they’ll be around for a while. 


The vendor offers an integration platform as a service (iPaaS), but they also provide a few other solutions. For example, they have solutions that cover data integration scenarios—where data from multiple 3rd-party platforms is extracted, transformed to a specific data model (that aligns with what the data warehouse uses), and then loaded into a data warehouse. And they provide master data management services to help organizations create a single source of truth for specific types of data.


Similar to Informatica, Jitterbit offers a variety of complementary services. Beyond their iPaaS offering, they provide an electronic data interchange (EDI) product, which enables business partners to exchange documents (e.g. purchase order) electronically via a standardized format. They also allow organizations to build applications that serve specific use cases, like procurement, customer dashboards, PTO, etc.


The iPaaS vendor provides countless pre-built connectors across categories; these include everything from mainstream categories for B2B companies (e.g. CRM) to supply chain and logistics solutions (e.g. Procurify). Celigo also offer an API management feature, which allows your team to develop, document, maintain, and deliver APIs.


The platform specializes in supply chain integrations—making it highly valuable for organizations that need to streamline their supply chain operations. They offer connectivity through multiple means, whether that’s through API integration, EDI, or managed file transfer (MFT), and they help their clients connect with widely-known trading partners, including Amazon, Costco, Lowe’s, and Target. 

Given Cleo’s level of specialization, it’s fair to assume that most organizations aren’t a fit for their solutions.


The robotic process automation (RPA) software has historically relied on “bots”, or custom scripts, to automate tasks at the user interface level. However, the platform has added the ability to build API integrations by acquiring Cloud Elements

With RPA and API integration capabilities, the platform can handle just about any integration scenario you need support with. But given that they’ve only somewhat recently invested in API-based integration capabilities, these capabilities are likely to be less robust than the tools that were built with API integration in mind.

Related: The top benefits of API integration

API Integration tools for customer-facing use cases

When you’re looking to outsource API-based product integrations, you’ll have a few different types of solutions to consider: an embedded iPaaS, an integration marketplace as a service, and a unified API platform.

The three most common software categories for building product integrations

Here’s a break down of some of the vendors within each category:

Tray Embedded 

Tray.io’s embedded iPaaS solution lets you and/or your customers build product integrations within your platform. 

While the solution offers application connectors that expedite integration development, the platform itself requires a fair amount of technical expertise to use. As a result, the vast majority of your employees and/or client's employees can’t participate in the process of building integrations, which causes integration backlogs to form and frustration for everyone involved.

Related: The benefits and challenges of embedded iPaaS solutions


Pandium offers an integration marketplace as a service (iMaaS), which lets users design and embed an integration marketplace in their application through an iFrame. 

Like Tray Embedded, Pandium allows you to build integrations faster via pre-built connectors. The integration marketplace it helps you build can also increase awareness and adoption of your integrations. 

However, the platform only lets you build one integration at a time. Moreover, its maintenance capabilities leave a lot to be desired—it doesn’t let you determine specific integration issues and the steps for remediating them.

Related: How a unified API solution compares to an iMaaS provider


Kombo offers a universal API that, if built to successfully, lets you integrate your product with dozens of HRIS and ATS solutions 

The platform allows you to integrate at scale; it also helps you integrate with just about any HRIS and ATS platform your clients and prospects need. 

That said, you likely need to integrate your product with tools that extend beyond HRIS and ATS (such as CRM, file storage, or ticketing tools). Also, the tool lacks comprehensive functionality in tracking and resolving integration issues. This can prevent you from addressing integration issues quickly (or as fast as your clients expect), and it can force your developers to invest more time on the tedious, unproductive task of understanding and troubleshooting integration issues. 


Merge also provides a universal API, but it covers a broader range of software categories, including CRM, marketing automation, file storage, ticketing, and accounting. 

The platform also provides comprehensive integration management capabilities that enable customer success or support to identify issues on time and work with the client on resolving them, quickly. And the platform provides common models across software categories that cover the majority of objects and fields your clients want to access, along with advanced features for accessing any data that extends beyond these common models.

You can learn more about Merge by scheduling a demo with one of our integration experts.

API integration tools FAQ

In case you still have questions on API integration tools, we’ll address a few commonly-asked ones below.

How much do API integration tools typically cost?

The answer naturally depends on your individual wants and needs—from the number of integrations you need to build to the level of support you want to have—but the price typically ranges from $10k to 100k per year. 

That said, there are many exceptions. There can be startups that only need to pay a few thousand dollars per year, while enterprise companies pay several millions of dollars annually.

Are any API integration tools free? 

Many tools offer a free plan that’s meant to help you become familiar with the tool’s UI, features, and functionality. 

These plans may help you build a few integrations, but any business that wants to fully adopt the tool will need to go beyond this threshold and commit to a paid plan. 

What are some examples of API integrations? 

The answer can be divided by customer-facing and internal API integrations. 

In the case of the former, common use cases include user provisioning and de-provisioning in your product, syncing tickets between your product and users’ ticketing systems, and pulling files from clients’ file storage systems into your product. In the case of the latter, it can be adding new hires from your ATS to your HRIS, routing leads between your marketing automation platform and your CRM, and syncing invoices between your CRM and your ERP system.