The JSON viewer that lives in your browser
Open any API response or JSON file and read it instantly as an interactive tree. Plus a formatter workbench, a local JSON diff, JWT decoding, and a DevTools panel — all 100% private, free, no account.
✓Free forever · No sign-up · Works offline · Zero data collected
✦ New: local JSON diff, instant JWT decode, recent-input history & format-on-paste
{"user":{"id":91,"name":"Ada Lovelace","active":true,"roles":["admin","editor"],"address":{"city":"London","country":"UK"}}}Six tools in one extension
A page viewer, a workbench, a local diff tool, JWT decoding, a DevTools panel and a right-click action — everything you reach for when working with JSON.
Auto JSON page viewer
Open any API endpoint or .json URL and the raw text becomes an interactive, syntax-highlighted tree — collapsible, searchable, with click-to-copy JSON paths and a keys · depth · size readout.
Resizable workbench
A formatter that docks in a side panel and stays open while you browse. Format, minify, sort, validate, escape — with live validation, recent-input history, format-on-paste, and a pop-out window.
Local JSON diff
Paste two JSON documents and get a proper line-level diff — additions and deletions highlighted, computed entirely in your browser. No file ever touches a server.
JWT decode & tolerant parsing
Paste a raw JWT and decode its header, payload and expiry inline — no network call. Pages that are NDJSON or have JSONC-style comments/trailing commas render instead of failing outright.
DevTools panel
Open DevTools → JSONKit. Every JSON network response is captured with method, status and size — filter by any of them, explore one in the tree, or export the whole session as a file.
Right-click to format
Select JSON anywhere on a page and choose “Format selection in JSONKit” to open it prefilled. The fastest way to make a blob of JSON readable.
Every workbench action has a keyboard shortcut
Shown right in each button's tooltip, so you never have to memorize them up front.
Open any JSON in the full toolkit — one click
Viewing an API response? Hit “Open in JSONKit” and the exact JSON opens — prefilled — in whichever tool you need. No copy-paste, no re-typing.
Built for everyday JSON work
100% private — by design
Every byte is processed on your device. The extension makes zero network requests, has no analytics, and never uploads your JSON. Paste production payloads without a second thought.
Up and running in 30 seconds
Install
Add JSONKit to your browser from the Chrome Web Store in one click.
Open any JSON
Visit an API endpoint or .json file — it renders as an interactive tree automatically.
Format & explore
Click the toolbar icon for the workbench, or open DevTools for the network panel.
Prefer not to install?
Use the full toolkit on the web — 50+ free JSON tools, nothing to download.