Format, validate, repair and convert JSON locally in your browser. Your data is never uploaded.
Users
5
+1 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
2
0 in 30 days
Store rank
#246K
#206K among extensions
Version
1.0.3
updated 27 Sep 2026
Users
monthly, 2 months
Latest, 19 Oct 2026:5 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 months
Latest, 19 Oct 2026:2 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 JSON Formatter & Validator - JFmt
JFmt is a local-first JSON toolkit for developers. Install this extension to open the JFmt editor from the Chrome toolbar in one click.
What you can do:
• Format, minify, escape, unescape, repair and sort JSON
• Convert between JSON, CSV, XML, YAML, TOML, query strings and Postman
• Explore data in a foldable tree or mind map, with inline edit
• Decode JWT, preview Lottie, and generate models in SQL, Java, C#, Go and Dart
• Load examples and keep a local auto-save draft on this device only
Why install it:
• One toolbar icon instead of searching for a formatter every time
• Your JSON is processed in the browser and is not uploaded to JFmt
• No account, no extra permissions, and the extension does not read other websites
• Clicking the icon opens https://jfmt.dev/?app=1 in a new tab (Focus mode)
This listing is a thin launcher. JSON features update when jfmt.dev is deployed; you do not need to wait for a new store version to get formatter fixes.
Privacy policy: https://jfmt.dev/privacy
Homepage: https://jfmt.dev
Support: https://jfmt.dev/support