---
title: 'Explaining 9 Types of API Testing'
description: 'Learn about 9 different types of API testing with detailed explanations.'
image: 'https://assets.bytebytego.com/diagrams/0017-9-types-of-api-testing.png'
createdAt: '2024-03-10'
draft: false
categories:
  - api-web-development
  - software-development
tags:
  - API Testing
  - Software Testing
---

![](https://assets.bytebytego.com/diagrams/0017-9-types-of-api-testing.png)

*   **Smoke Testing**
    This is done after API development is complete. Simply validate if the APIs are working and nothing breaks.
*   **Functional Testing**
    This creates a test plan based on the functional requirements and compares the results with the expected results.
*   **Integration Testing**
    This test combines several API calls to perform end-to-end tests. The intra-service communications and data transmissions are tested.
*   **Regression Testing**
    This test ensures that bug fixes or new features shouldn’t break the existing behaviors of APIs.
*   **Load Testing**
    This tests applications’ performance by simulating different loads. Then we can calculate the capacity of the application.
*   **Stress Testing**
    We deliberately create high loads to the APIs and test if the APIs are able to function normally.
*   **Security Testing**
    This tests the APIs against all possible external threats.
*   **UI Testing**
    This tests the UI interactions with the APIs to make sure the data can be displayed properly.
*   **Fuzz Testing**
    This injects invalid or unexpected input data into the API and tries to crash the API. In this way, it identifies the API vulnerabilities.