Spectator is an open-source REST-API testing app for Linux

What is Spectator?

Spectator is a free, open-source (Libre) REST-API testing program for Linux. It is written in Vala programming language and GTK.

The app allows developers to make requests to test their web endpoints, create custom environments, and save everything within a collection.

A Linux alternative to commercial software

Spectator is a native API-testing alternative to many commercial solutions and services like Postman, SoapUI, Katalon Studio, Apigee, and Assertible.


Spectator API Testing app
Spectator API Testing app
  1. A lightweight app that does not require extensive CPU or RAM resources
  2. Server request with custom parameters
  3. Attach a script payload
  4. Response viewer
  5. Add unlimited requests
  6. Easily add your frequent requests
  7. Requests support for POST, GET, PUT, DELETE, PATCH, and HEAD
  8. Add a custom header to your request
  9. Add collections to your request which helps in working on several projects and environments
  10. Helps you assign many environments
  11. It has a built-in dark theme
  12. Allows following the redirect automatically
  13. Users can set the redirects limits and network requests timeout manually
  14. Clone any request with one click
  15. History viewer to access frequent requests
  16. Built-in script's editor
  17. It manages basic proxy server automatically
  18. Works seamlessly for Linux systems
  19. View request information: status, time, size, JSON response, header, and cookies
  20. Views JSON response in a tree view


Spectator is available for Linux systems, as Linux users can build it from the source or install it using Flatpak with Flathub repo.

To install Spectator, make sure you have your Flatpak ready, as well as Flathub, installed, then simply run:


Spectator is released as an open-source solution under GPL-3.0 License.


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