JaSON

A simple, easy to use HTTP client to send API requests from within Chrome and see formatted, syntax highlighted responses.

JaSON: Easy-to-use HTTP Client Chrome Extension

"JaSON" is a free, open-source Chrome extension that acts as a simple HTTP client. It's perfect for testing and debugging a variety of APIs and web services. With automatic cookie support for handy authentication, a variety of HTTP methods, dark or light themes, and a history of previous requests, JaSON provides an easy, efficient experience. It also formats input/output and supports multiple content types, making it truly adaptable to a multitude of testing needs.
Install from Chrome Web Store

Extension stats

Users: 8,000+
Rating: 4.37
(38)
Version: 5.0.25 (Last updated: 2021-04-23)
Creation date: 2020-06-28
Risk impact: Moderate risk impact
Risk likelihood:
Manifest version: 2
Permissions:
  • http://*/*
  • https://*/*
Size: 1.89M

Other platforms

Not available on Android
Not available on Firefox
Not available on Edge
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Extension summary

Great for testing and debugging JSON and XML APIs, RESTful APIs, GraphQL APIs, web services, web applications and more.

Cookie support: Automatically sends cookies from Chrome. This is extremely handy for APIs which require authentication. Simply authenticate via your browser as normal and JaSON will send cookies for requests which match.

HTTP methods: GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS

Dark/light theme: Change the colour theme to suit your work environment.

Request history: Keeps request history with full text search. Individual history items can be deleted, or marked as a "favourite" for easy access. History from previous versions of JaSON will be automatically migrated. Stores history in IndexedDB for improved performance.

Formatted input/output:

See more

User reviews

These summaries are automatically generated weekly using AI based on recent user reviews. Chrome Web Store does not verify user reviews, so some user reviews may be inaccurate, spammy, or outdated.
Pros
  • Easy to use interface
  • Useful for testing API with JSON responses
  • Remembers previous requests
Cons
  • Doesn't work for some users
  • Could use more polish
  • Doesn't work for XML
  • Doesn't format JSON response in a readable way
Most mentioned
  • Useful for testing API with JSON responses
  • Easy to use interface
  • Doesn't work for some users
User reviews
by Benny Meade, 2024-05-18

This extension provided exactly what I was looking for - the ability to test an API which responds to HTTP POST requests with JSON responses. One feature I love is that it remembers previous requests which makes it very easy to fire off an earlier request again or change the JSON body of the request and then do the same. Excellent!
by Mark Pearson, 2022-12-15

I honestly love this extension <3
by Gilbert Lopah, 2022-09-09
View all user reviews

Extension safety

Risk impact

JaSON requires a few sensitive permissions. Exercise caution before installing.

Risk likelihood

JaSON has earned a good reputation and can be trusted.

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Promo images

JaSON small promo image
Small promo image

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