Best Tool for In-Editor API Testing in 2026
Last Updated: October 5, 2025
Switching to a separate tool just to test an API call interrupts the flow of writing code. In-Editor API Testing tools let developers test API endpoints without leaving their code editor.
Developers use in-editor testing to stay in their workflow while verifying API behavior.
Thunder Client
Thunder ClientLightweight API Testing Extension for VS Code is the best for In-Editor API Testing. So, let’s take a closer look at this tool.
Thunder Client is a REST API testing tool that lives inside Visual Studio Code. You can send requests, check responses, and organize your API tests without opening another program. It works just like other API testing tools but runs directly in your code editor.
The extension saves all your requests and settings on your own computer. This makes it fast, private, and able to work without internet. You can also save your testing data to Git repositories, making it easy to share with your team.
Thunder Client offers both free and paid versions. The free version works great for basic testing, while paid plans add features like unlimited test runs, team management tools, and advanced testing options for businesses.