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types of APIs

Today’s applications depend on APIs to exchange data and functionality. But with so many APIs out there, it can be massive to understand the different types of APIs and how they’re used.

APIs act as bridges between two applications that allow them to communicate and exchange their data and functionality with each other. This is essential for our interconnected world, where features like ride-sharing apps integrating maps or social media platforms sharing content across apps depend on APIs.

APIs are the adhesive that holds our digital world together. They allow a flow of information, promote collaboration seamlessly, and drive innovation across various aspects of our lives in this generation.

Moreover, APIs are used in various industries, not limited to consumer apps, from finance (secure transactions) to healthcare (electronic health records) and logistics (tracking shipments). APIs are the backbone of efficient data exchange and innovation across sectors.

This article will be your guide to the different types of APIs. Whether you are a budding developer or just starting your journey, understanding the types of APIs allows you to build more efficient and powerful applications.

Types of APIs by Access

There are four types of APIs commonly used in web services:

1. Public APIs

Free public APIs are crucial types of APIs that help apps connect and share information easily. Imagine apps being stuck in their vessel, unable to access anything outside themselves.

Public APIs fix this by creating bridges between them, allowing for more collaboration and innovation.

  • Free Pass to Data:

    Access to data from weather forecasts and currency conversions to social media feeds and news updates, unlocking information for developers to integrate into their apps

  • Increase App’s Functionality:

    Public APIs are pre-built toolkits. Developers can extract their API functionalities, saving them time and resources.

  • Cost-effective:

    Public APIs are free to use (with limitations on usage in some cases). This makes them ideal for startups and individual developers.

  • Data Accuracy:

    Since anyone can access public APIs, data accuracy and ownership can be concerns.

2. Private APIs

Unlike public APIs, Private APIs are another type of API designed for internal use and operate behind the scenes, serving as a secure passageway within an organization.

Streamlining communication and data flow between different departments or applications within the company.

  • Increase Security and Control:

    It prioritizes security by restricting access only to authorized users within the organization. This is necessary for protecting sensitive data.

  • Customized functionality:

    Customized as per the specific needs of an organization, it integrates existing internal systems and workflows, promoting efficiency and avoiding complex workarounds.

  • Faster Development:

    Provide pre-built functionalities for internal data access that increase development processes. Developers can focus on the functionalities of the application instead of starting from scratch.

  • Data Accuracy:

    Great for security, but they offer inaccurate internal data, limited information for developers, and kept data systems that were unreliable in the API. This can cause bad decisions, wasted resources, and operational issues.

3. Partner APIs

Partner APIs are another type of API that works as secret handshakes and enables businesses to share data and functionality in a controlled manner.

It facilitates collaborations like a travel booking app partnering with an airline API to offer real-time flight information. A restaurant management system integrating with a delivery service API to streamline order processing creates a win-win situation for both parties.

  • Controlled Access:

    Partner APIs require authorization and authentication. This ensures data is only shared with trusted partners.

  • Customized functionality:

    Can be tailored to specific partnerships (share only relevant data and functionalities).

  • Integration Complexity:

    Integrating a partner API can be more complex compared to public APIs. Businesses need to establish secure communication channels and agree on data formats and protocols.

  • Limited Availability:

    Partner APIs are not readily available, like public APIs. Businesses need to establish partnerships and negotiate access terms.

4. Composite APIs

Composite APIs function by interacting with various APIs to deliver a data flow for your application seamlessly. Instead of making multiple separate cells for different APIs, you can bundle them into a single composite request. This reduces network traffic and improves overall efficiency.

  • Data Transformation:

    It translates information from these sources into a single, common language your application can understand. This unifies the data flow and makes everything work smoothly together.

  • Glitch Management:

    Instead of relying on multiple APIs, which can be prone to errors, a composite API combines them into a single, more reliable source. This reduces the complexity of handling glitches and ensures your application runs uninterrupted.

  • Smoother User Experience:

    With faster data retrieval, it saves developers time and effort and contributes to a more responsive and enjoyable experience for your app’s users.

  • Challenges:

    Building and maintaining a composite API requires more effort than using individual APIs. Also, troubleshooting issues can be more complex when dealing with a composite API.


Public APIs

Private APIs

Partner APIs

Composite APIs


Anyone with internet accessInternal use onlyAuthorised partners onlyIntegrates various APIs


LowerHighestModerateDepends on integrated APIs


LimitedHighestModerateDepends on integrated APIs




Wide range of usesInternal developmentCollaboration with partnersSimplify API interaction


Weather API, Social Media APIHR system APILoyalty program APITravel booking API (combining flight and hotel APIs)


EarlierEarliestLaterMost Recent

Types of APIs by Architecture


REST APIs are one of the most popular types of APIs for applications to talk to each other. They use standard methods like GET and POST to request and receive data in a common format (often JSON). This makes them simple, flexible, and widely used.

  • Simplicity:

    They are easy to design and understand.

  • Flexibility:

    They can be used to access a variety of data and functionality.

  • Adaptability:

    It can handle a lot of traffic.

  • Interoperability:

    They allow applications from different vendors to work together.


SOAP APIs provide a secure way for applications to communicate and exchange data. However, their complexity and potential performance make them less suitable for modern, lightweight web applications.

  • Structured and Formal:

    SOAP APIs follow a stricter, more formal approach. They rely on XML for data formatting and adhere to predefined standards.

  • Secure and Reliable:

    Where reliability is crucial, this structured approach makes APIs well-suited for secure data exchange in enterprise environments.

  • Rich Feature Set:

    Supports functionalities like remote procedure calls (RPCs) and complex data structures.

3. GraphQL APIs

GraphQL APIs are one of the powerful types of APIs that offer a flexible approach to data retrieval, especially for complex data models and client-focused applications.

With GraphQL, the client specifies the exact data fields it needs from the server’s data model. This eliminates the need for multiple REST calls and retrieves unnecessary data, boosting performance.

  • Effectiveness:

    By requesting only the required data, it streamlines data transfer and improves overall performance.

  • Flexibility:

    Since clients control the data they receive, the system can easily adjust to their changing requirements.

  • Maintainability:

    Because the data organization is well-defined, creating and maintaining client and server apps is easier.

  • Improved Developer Experience:

    The clear structure and predictability of data retrieval make development smoother.




GraphQL APIs

Data Format








Error Handling

Simpler mechanismsMore complexDetailed error messages

Ideal for

Web applications, mobile appsEnterprise data exchange, high-securityComplex data models, client-driven application


Weather APIs, social media APIsFinancial transactions, healthcare dataE-commerce applications, content management systems


Simple, flexible, widely usedSecure, reliableEfficient, customisable data fetching


Can be inefficient for complex dataMore verbose, complex to developRequires learning GraphQL query language.

Types of APIs by Purpose

1. Open Data APIs

Open Data APIs are a tool that allows anyone with an internet connection to access and utilize a wealth of information. The API layer sits on top of the data, organizing it and providing a structured way for applications to search for and request specific information.

  • Transparency:

    By making information readily available, open data fosters transparency within governments and organizations.

  • Development:

    Developers can integrate Open Data APIs to create new applications and services that benefit various sectors, like traffic prediction apps or public health initiatives.

  • Cost-saving and Efficient

    Businesses and organizations can avoid the cost and time associated with collecting their data by utilizing existing open datasets through APIs.

2. Data APIs

Data APIs act as intermediaries between applications and data sources. They provide a standardized way for applications to request, retrieve, and manipulate data from various locations.

  • Streamlined Communication:

    They offer a consistent interface for interacting with different data sources, eliminating the need for understanding complex data structures or storage mechanisms.

  • Simplicity:

    Data APIs provide a standardized way to access data, reducing development complexity.

  • Scalability:

    Open APIs are suitable for large-scale applications, they can handle a high volume of data requests.

3. Payment APIs

Payment APIs are a specific type of API that works as a bridge between our online store, your customer, and their bank account. That’s what payment APIs do. They handle complex online payments securely and efficiently.

  • Secure Transactions:

    Payment APIs encrypt sensitive financial data during transfer, protecting your customers’ information.

  • Frictionless Checkout:

    Customers can pay directly on your website or app without needing a separate payment page.

  • Real-time Updates:

    Get instant feedback on transaction status, allowing you to manage orders and inventory effectively.


Open Data APIs

Data APIs

Payment APIs

Data Source

Publicly available datasetsVarious data sources (databases, web services, etc.)Payment processors


Transparency & InnovationAccess & manipulate dataSecure online payments


May vary depending on the sourceVaries depending on the APIHigh focus on security


Publicly accessibleControlled by the data owner
Controlled by the payment processor


LowerVaries depending on the APIModerate


Weather data, demographicsSocial media data, stock market dataStripe, PayPal, Square


Transparency, App developmentEfficiency, Scalability, InteroperabilityIncreased sales, Reduced costs, Enhanced security


Anyone with internet accessRequires specific access (may be free or paid)Requires integration with payment processor


The different types of APIs offer a variety of options to suit different needs. From the open and accessible public APIs to the secure and tailored partner APIs, each type serves a distinct purpose. REST APIs provide a familiar and lightweight approach, while SOAP APIs excel in complex enterprise communication.

GraphQL emerges as a powerful tool for efficient data retrieval within applications. Understanding these differences enables developers to choose the most effective API for their projects, fostering seamless communication and data exchange across applications and services.

Frequently Asked Questions

Q1. What are the best types of APIs that are available?

Four types of APIs are commonly used, and the “best” one depends on your specific needs.

  1. REST APIs: Simple and flexible, good for most web applications.
  2. SOAP APIs: Super secure, ideal for enterprise data exchange with high-security needs.
  3. GraphQL APIs: Efficient for complex data models and client-driven applications.
  4. Open Data APIs: Public data for anyone to access and use for innovation.

Q2. How do different types of APIs benefit businesses?

Different types of APIs help businesses:

  1. Work faster by streamlining data access.
  2. Do more by integrating new features.
  3. Reach further by connecting with partners and customers.
  4. Save money by using existing functionality.
  5. Stay secure with strong data protection features.

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