A simple, easy to use HTTP client to send API requests from within Chrome and see formatted, syntax highlighted responses.
Users
4,000
0 in 30 days
Rating
4.5 / 5
unchanged in 30 days
Ratings
38
0 in 30 days
Store rank
#15K
#13K among extensions
Version
5.1.0
updated 3 Jul 2026
Users
monthly, 3 years
Latest, 15 Oct 2026:4,000 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 years
Latest, 15 Oct 2026:38 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About JaSON
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:
Provides an IDE like experience when editing request body and headers. Automatically formats request/response body syntax and colour based on content type.
Content type:
Supports JSON, XML, and form encoded data by default. Additional content types can be used by setting a custom content type header.
New and improved:
Completely re-written, new styling, layout, colours, additional features and improved performance.
100% open source
Source code is available from GitHub.
Privacy policy
https://github.com/shanebell/JaSON/blob/master/privacy-policy.md