JSON Formatter, Validator & Beautifier
Paste JSON into a popup and get it pretty-printed, validated, and syntax-highlighted instantly — with the exact line and column of any error. No tab switch to a web tool, no upload, no account.
How to use it
- Install the extension from the Chrome Web Store and pin it to your toolbar.
- Copy the JSON you want to inspect — an API response, a config file, a webhook payload.
- Click the toolbar icon and paste it into the popup.
- Read the formatted, syntax-highlighted result — or, if the JSON is invalid, the exact line, column, and a plain-English reason such as “trailing comma before }”.
- Copy the result to your clipboard or download it as a file.
What you get
Free
- Pretty-print with 2-space, 4-space, or tab indent, applied as you paste.
- Validation with exact error location — line, column, a caret at the offending character, and a plain-English explanation instead of a cryptic parser message.
- Syntax highlighting on the formatted result, so nested structures are easy to scan.
- One-click minify when you need compact output.
- Recursive key sorting, to normalise inconsistent API responses or make two blobs comparable by eye.
- Copy to clipboard or download as a file; your indent style, sort-keys default, and theme are remembered.
Premium — $5, paid once
- A collapsible tree view with search/filter and one-click copy of any node’s JSON path.
- JSON to CSV and JSON to YAML conversion, both directions.
No subscription and no account: pay once, keep the features.
What it can and can’t see
It requests exactly one Chrome permission: storage, used to remember your preferences on your own device. It declares no host permissions and injects no content scripts, so it cannot read the pages you visit, your open tabs, or your browsing history. The JSON you paste is processed locally, inside the popup.
Our own code collects nothing — no analytics, no telemetry, no tracking of any kind, in this extension or any other we ship.
One honest exception, disclosed: the extension bundles ExtensionPay to handle the premium upgrade, and that component does make network calls — it checks whether you have purchased, and opens its hosted checkout if you choose to upgrade. ExtensionPay writes an install timestamp for every user from the moment of install, and after a purchase holds a licence key and the checkout email you gave it. Card details go directly to ExtensionPay and Stripe and are never seen by us. The full disclosure is in our privacy policy. That is the only network traffic involved — your JSON is never part of it.
Try it
It is free to install, and the core features above stay free.