API-Testly

API-Testly is a tool for testing APIs. It supports scripting (pre-request and post-response JavaScript) and environment variables, so you can chain requests together, for example by saving a login token and reusing it everywhere. You can also export and import requests to share them or move them between machines.

I'm a developer, and I built it because most other API tools I tried were slow and hard to work with. API-Testly is meant to be simple and fast. It doesn't need admin permissions to install or run, and your data stays on your computer.

Features
Learn more about what API-Testly can do.
Download
Get the latest version of API-Testly here.
Scripting Guide
Automate requests with pre-request and post-response scripts.
Frequently Asked Questions
Get answers to common questions.

Screenshots

Click a screenshot to enlarge it.

Folder tree and context menu — Folder tree and right-click menu

Key features:

Native Windows Forms desktop application for Windows 10 and Windows 11.
Folders and requests in a tree on the left. Create, rename, delete, copy and paste with a right-click.
Supports GET, POST, PUT, PATCH and DELETE.
Headers and query parameters edited in simple key/value grids.
Every body type: none, form-data (including file uploads), x-www-form-urlencoded and raw.
Variables: define them once and use {{name}} in URLs, headers, params and bodies.
Pre-request and post-response scripts written in JavaScript, per request.
Sandboxed scripting engine. Scripts cannot access your files or other programs.
Response viewer with status, time, size, pretty-printed JSON and a headers table.
Import and export: export a request to JSON, import it elsewhere, or bulk-import a JSON file of requests into a folder.
Resizable panes: drag the dividers between the tree, the request and response areas, and the script editors.
Auto-save. Your workspace is saved as you type. No account or sign-up.
Built-in Help → Scripting Guide.
Packaged and installed with Velopack.

Download

API-Testly-win-Setup.exe
Installer for Windows 10 / 11, 64-bit.

The installer is built with Velopack.

Free for now. API-Testly is free to use at the moment. Future versions may become a paid product. Please read the License before installing.

Scripting Guide

Every request has an optional Pre-request script, which runs before the request is sent, and an optional Post-response script, which runs after the response arrives. Output from console.log appears in the Console panel on the Scripts tab.

Object	Available in	Members
`env`	Both	`get`, `set`, `has`, `remove`
`request`	Pre-request	`getUrl`, `setUrl`, `getMethod`, `setMethod`, `getHeader`, `setHeader`
`response`	Post-response	`status`, `statusText`, `body`, `headers`, `json`
`console`	Both	`log`, `error`

Example: save a token from a login response, then use it in other requests.

// Post-response script on your "Login" request
if (response.status == 200) {
    env.set("access_token", response.json.accessToken);
    console.log("Token saved");
}

// In any other request's Headers grid:
// Authorization: Bearer {{access_token}}

Frequently Asked Questions

Is API-Testly free?
Yes, it is free to use for now. It may become a paid product in a future version.

What is it built with?
API-Testly is a Windows Forms application, packaged with Velopack.

Where is my data stored?
Locally on your computer, in your user profile's application data folder. Nothing is uploaded anywhere.

Are scripts safe to run?
Scripts run in a sandboxed JavaScript engine that only exposes env, request, response and console. They have no access to your file system or other programs.

Can I share requests with other people?
Yes. Export a request as a JSON file and import it on another machine, or bulk-import a JSON file of requests into a folder. To share the app itself, send people to this page. Do not redistribute the installer (see License).

Which platforms are supported?
Windows 10 and Windows 11.

License

API-Testly is free to use at this time. Sanle Tech Solutions may introduce paid licensing in future versions.
You may not redistribute, repackage, resell, sublicense, or host copies of API-Testly or its installer on other websites or services. Link to this page instead.
You may not reverse engineer, decompile, or modify the application, or remove any copyright or branding notices.
Sanle Tech Solutions retains ownership of the application and all related intellectual property.
The software is provided "as is", without warranty of any kind.