Software Development Kits (SDK) and Application Programming Interfaces (APIs) are critical components of your app’s development. However, these two terms sometimes overlap, often leading to confusion.  

Knowing their differences and how you can take advantage of them can significantly help you improve your application. This piece tackles their distinct features and outlines how you can utilize them to supercharge your app.  

What is SDK?

A software development kit (SDK) is a set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar development platform. 

What is an API?

An application programming interface (API) is a set of protocols and tools for building application software. It is a set of clearly defined methods of communication between various software components. Most companies, especially tech companies, have built APIs for their customers or for internal use. 


The main differences between SDK & APIs are

  • APIs facilitate the communication and integration of software 
  • SDK provides the foundation to build an application specifically for a platform 
  • SDKs contain APIs; APIs don’t contain SDKs 

API, as a part of an SDK, is lightweight and specialized based on the function intended. Meanwhile, SDKs have a collection of utilities to create a new application or add new functionalities.  

What’s the Difference between an SDK and an API?

  • When a developer uses an SDK to create systems and develop applications, those applications need to communicate with other applications. An SDK includes an API to make that communication possible. On the other hand, while the API can be used for communication, it cannot create a brand-new application. 
  • The real difference is that an API is really just an interface for a service, while an SDK is the tools/components/code fragments that have been created for a specific purpose. 
  • An API acts as an interface between different applications or platforms and helps various software programs interact. They usually contain specifications that can be used to interface between different software programs. On the other hand, the SDK consists of development tools and pre-written code that developers can use to build their applications. The SDK usually reduces the workload and time required for developers to write their unique code to build software applications. 
  • The API does not have any written sample code but includes a detailed description of function calls and function prototypes’ behavior. The SDK consists of sample programs, technical descriptions, utility programs, and debugging tools for programmers to integrate into the development of applications, thereby saving a lot of time and effort. 
  • APIs may contain routines, data structures, protocols, and object class specifications to facilitate interaction between different programs. To facilitate interaction with embedded systems, the SDK usually consists of files or APIs in the form of complex hardware. The SDK plays a vital role in eliminating work duplication and saving developers the time to create new software applications. An API usually includes a set of rules and specifications, and software programs will follow these rules and specifications to facilitate easy interaction. 

When to use SDK and when to use an API?

Developers always use the SDK when building applications. Besides, there are SDKs specifically designed for specific platforms, for example, an Android SDK would be specific to android applications. The API is used to communicate with external applications or platforms through various methods and protocols. 

In short, when developing any software application, engineers will use the SDK. When you need to communicate with other third-party service providers (application/platform), you will use API integration. Which may perhaps be part of the SDK.