Best 11 API Integration Tools for Connected Business

APIs keep business software connected, but managing integrations isn’t always straightforward. Different systems, data formats, limitations, and security requirements can turn a simple connection into a real challenge. That’s where API integration tools make all the difference.

If you’re looking for the best tools to handle API integrations, we’ve got you covered. We’ve been delivering software product development services since 2014. Among our 200+ projects, we’ve integrated Salesforce, HubSpot, and Zapier and built custom APIs from scratch.

In short, we know what works and will share it with you. Here, you’ll find the list of API integration tools carefully selected by our software architect — a professional with 15 years of experience. But before looking at available tools, let’s clarify what API integration platforms are and their role.

What is an API integration tool?

An API integration tool helps connect different software systems without the hassle of building integrations from scratch. It takes care of authentication, data transformation, and communication between APIs, eliminating the need to write custom code or handle errors manually.

You don’t need to be a developer to use one. Many API integration platforms offer no-code or low-code options, making it easy for non-technical users to set up workflows and automate data exchange.

The gains from using API integration tools are solid:

• Faster setup as you skip the custom coding
• Less maintenance as the tool handles updates, security, and API changes for you
• Scalability to easily add new connections as your business grows

In simple words, API integration tools streamline the integrating process, saving you time and effort while keeping your software ecosystem connected.

When to use API integration platforms: 4 use cases

API integration tools are perfect for automating data flow, integrating new services, or syncing systems without extra hassle. Let’s look at the key scenarios where these tools are a game-changer for your business.

Connecting the old with the new

Many businesses still use legacy systems to run their core operations. API integration is like a bridge that helps connect these older systems with new tools, such as modern CRMs or ERPs.

One of our clients, a manufacturing company, faced this challenge. They needed the ERP we were building to work seamlessly with their legacy inventory management system. An API integration platform helps a lot in cases like this, enabling real-time data exchange without disrupting existing operations.

Automating data exchange between different platforms

Businesses that need real-time data synchronization will relate to this scenario. When data doesn’t flow smoothly between systems, you end up with outdated information, delays, reporting errors, and extra manual work.

Take e-commerce store owners as an example. Their inventory must be updated every time an order comes in, customer data must be synced, and shipping labels must be generated. API integration platforms automate all this, saving them countless hours of manual work.

Bringing in third-party services

Let’s say you have a great CRM, but it lacks e-commerce-specific features. That’s no problem with API integration platforms. With them, you can implement third-party services like shipping APIs, marketing automation tools, and more right into your CRM.

Take, for example, our client Creadoor, a marketplace for content creators. To enrich their MVP’s functionality while keeping the project within budget, we integrated Stripe for payment processing and Layer for in-app chat instead of building it from scratch.

Building scalable ecosystems

If you’re working on a SaaS product or a complex enterprise platform, you definitely need API integrations. With these solutions in place, you’ll create a flexible and scalable ecosystem where different parts communicate seamlessly and integrate with other tools your customers might use.

As you can see, API integration tools are quite helpful in making the integration process faster and more efficient, no matter if it’s a popular CRM solution or a legacy system. Now, let’s dive into what you came here for: a list of top API integration tools.

Best API integration tools overview

We selected the best API integration platforms for each scenario we covered above. Let’s look at them so you can find the right solution for your needs.

Scenario a: Connecting the old with the new

Think of a manufacturing company. They’ve used the same old inventory management system for years, but now they want to connect it to a modern CRM like Salesforce. To track customer orders and inventory levels with a new CRM more efficiently, they may use the following API integration software:

MuleSoft

MuleSoft is an integration platform as a service (iPaaS) that helps businesses connect apps and data across on-premises and cloud environments — with legacy systems supported.

• Cost: Custom (comes at three tiers: Anypoint Integration Starter, Anypoint Integration Advanced, and API Management Solution)
• Pros: Scalable, secure, hybrid & cloud-native, robust API management
• Cons: High setup costs for enterprise-level tools, steep learning curve

Boomi

Just like MuleSoft, Boomi is another popular iPaaS platform. Yet, it’s easier to use, offering to build integrations by simple drag-and-drop gestures. It also supports on-premises, hybrid, and cloud deployments.

• Cost: It comes in five tiers: Base, Professional, Pro Plus, Enterprise, and Enterprise Plus at a custom quote. Costs start at $550/month.
• Pros: Offers intuitive interface and prebuilt connectors; good for hybring environments.
• Cons: Licensing costs can add up for large implementations.

Scenario b: Automating data exchange between different platforms

Let’s say you run an online store using Shopify. Wouldn’t it be awesome if new customer information was automatically added to your email marketing list in Mailchimp? Zapier and other API integration platforms we’re about to list make this possible:

Zapier

Zapier is an extremely user-friendly workflow automation platform. It integrates with over 7,000 apps and automates tasks between them. Ideal for small businesses and non-technical users who want quick automation wins.

• Cost: Offer a free plan with limited functionality; more advanced plans start at $20/month
• Pros: Quick implementation, user-friendly interface, suitable for small-to-medium businesses
• Cons: May struggle with complex, enterprise-level requirements

Make

Formerly known as Integromat, Make is more flexible than Zapier but still no-code-friendly. Ideal for businesses needing advanced workflows without diving into hardcore development.

• Cost: Offer a free plan with limited functionality; more advanced plans start at $9/month
• Pros: Affordable and highly customizable
• Cons: May have a steeper learning curve for beginners

Tray.ai

Tray.ai is an iPaaS that allows for event-based workflow automation, code-first API integration, and API management. Great for building complex, multi-step workflows across various apps.

• Cost: Comes at three pricing tiers: Pro, Team, and Enterprise at a custom quote
• Pros: Scalable, offers AI capabilities and strong enterprise security
• Cons: More suitable for technically advanced users

Scenario c: Bringing in third-party services

Now, consider a travel booking platform. You need to integrate it with payment gateways like Stripe and communication channels like Twilio for SMS notifications.

Or consider our client, Foresolutions, a company that provides route planning software. They needed a custom map that would be a central part of the functionality for optimizing route development for large vehicles. We chose to integrate with Azure Maps while customizing it to the client’s needs.

No matter what third-party service you want to integrate, here are the API integration platforms that will help you with it:

Workato

Workato is an enterprise-grade API integration platform that offers built-in security and compliance, workflow automation, AI-powered features, and data integration.

• Cost: Offers volume-based pricing
• Pros: AI-enhanced automation, no-code solution, secure for enterprises
• Cons: Requires ongoing monitoring to ensure API availability and updates

Celigo

Celigo is an integration platform as a service tailored for mid-market and enterprise automation, especially for eCommerce, SaaS, and ERP integrations. It offers a marketplace of pre-built API connector software ( but still allows custom coding when needed) for easily integrating with Salesforce, Shopify, Klaviyo, HubSpot, and other tools.

• Cost: Custom pricing depending on your needs
• Pros: User-friendly interface, pre-built connectors, AI-powered integrations
• Cons: Relies heavily on its library of pre-built integrations

Cleo

Cleo is a provider of supply chain integration solutions — CRM, ERP, e-commerce, and others — that focuses on the B2B segment.

• Cost: Custom pricing depending on your needs
• Pros: Offers a strong ecosystem and tools for API integration, orchestration, and management
• Cons: Can be complex to navigate and configure

Scenario d: Building scalable ecosystems

Let’s say you’re launching a SaaS platform that needs to handle thousands of API calls daily—connecting internal services, third-party tools, and external developers. You need an API management solution that scales effortlessly, ensures security, and provides deep analytics. Here are three solid picks:

Amazon API Gateway

Amazon API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale and software development stage.

• Cost: Pay-as-you-go, starts at $3.50/million requests
• Pros: Serverless scaling, strong AWS integration, cost-effective for high-volume APIs
• Cons: Higher technical complexity, AWS lock-in, requiring development expertise

Google Cloud Apigee

Just like Amazon API Gateway, Google Cloud Apigee is a platform that allows for easy API integration, development, publishing, managing, and monitoring.

• Cost: Pay-as-you-go, average cost varies based on usage
• Pros: Scalable API gateway, strong analytics, multi-cloud & hybrid support
• Cons: Steep learning curve for beginners, setup complexity

Azure API Management

Azure API Management by Microsoft is a platform as a service that allows for the entire API lifecycle management. It’s designed to handle high-traffic APIs while integrating natively with Azure services.

• Cost: Pay-as-you-go, average cost varies based on usage
• Pros: A user-friendly interface, seamless Azure integration, strong security and compliance
• Cons: Microsoft-centric, requires setup expertise, not ideal for small-scale projects

With so many API integration solutions available, there’s a solution for almost every use case—whether you need low-code automation or enterprise-grade API management. But what if none of these tools quite fit? Let’s explore when that might be the case.

When third-party integration platforms aren’t the right solution

As you see, there are numerous API integration platforms worth your attention. But in some cases, you need something more custom-tailored. Here are a few situations where building your own API integration might be the way to go:

Strict compliance and security requirements

Certain industries, like healthcare or finance, have strict compliance requirements that standard API integration tools may not fully support.

For example, if you’re in healthcare and need to integrate with electronic health record (EHR) systems, HIPAA regulations demand strict security, encryption, and access controls. Another example is fintech companies that deal with sensitive financial data and need airtight security: advanced encryption, fraud detection, and strict compliance controls.

Off-the-shelf solutions might not check all the compliance boxes, so a custom-built solution is the safer bet. A development team will assess software development risks, including security concerns, from the start and plan your solution to mitigate them.

Custom business logic

If your business has specific workflows and processes, ready-made API connector tools might not be flexible enough. It’s always best to hire dedicated developers who will customize the solutions to your exact needs.

We ran into this challenge while building an SMM platform for Attention Experts. The client had specific content publishing needs, including the ability to publish Instagram Stories straight from the platform. But there was no official API for that at the time. We created a custom publishing app using Instagram’s SDK to solve this, seamlessly connecting the client’s platform with Instagram for direct story publishing.

Integration with proprietary or obsolete legacy systems

While some API integration platforms support legacy software, they’re not a magic fix. If your system doesn’t have a modern API or uses outdated protocols, pre-built tools won’t be much help. In these cases, a custom-built integration is often the only way to bridge the gap and keep your data flowing.

Large data volumes

If your business deals with millions of API requests daily, pre-built integration tools might struggle to keep up. Many platforms have rate limits, latency issues, or extra costs for high-volume usage.

For businesses processing huge amounts of data — think financial transactions, IoT networks, or real-time analytics — you need an integration built for speed and efficiency. A custom solution lets you optimize for performance, reduce bottlenecks, and avoid hitting platform-imposed limits.

Cost inefficiency at scale

If you’re juggling multiple integrations across different departments, the costs of pre-built API tools can spiral fast. Many platforms charge per connection, per request, or based on data volume, making them surprisingly expensive at scale. At some point, building your own solution becomes the smarter financial move—giving you full control without recurring fees eating into your budget.

So, whether it’s strict regulations, massive data loads, outdated systems, security risks, or runaway costs, there are times when off-the-shelf solutions just won’t cut it. That’s when custom development isn’t just the better choice — it’s the only real option.

But where do you start? The right vendor will help you scope out your integration needs, optimize for long-term efficiency, define a development team structure, and build something that fits your business. If you’re thinking about custom API development, check out our discovery service costs — a quick way to get clarity on what a tailored solution might look like for you.

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To sum up

API integration tools are a game-changer for streamlining operations and keeping systems connected. But they’re not always the right fit, especially when dealing with complex business logic, obsolete legacy systems, or strict security requirements. In those cases, it may be best to choose the software development company and build a custom solution.

The first step? Defining what you need. We can help with it. At Clockwise Software, we specialize in API integrations, whether it’s building custom APIs from scratch or leveraging the right tools for your use case. We’re ready to help with the entire development lifecycle, from outlining the integration details with functional and non-functional requirements to actually creating and testing integrations.