JSON Lab

Utilities

Paste JSON in the popup. Format, minify, or validate. Errors show the parse message. All local.

ZIP built in your browser. No server binary download.

Done means

Paste messy JSON → Format → pretty output; Minify shrinks it; invalid JSON shows a clear error.

Format
Minify
Validate
Copy result

Permissions

None beyond default action UI

Job pattern: JSON utility

Install

Save the source package and unzip it.
Chromium: chrome://extensions → Developer mode → Load unpacked → select the folder.
Firefox: about:debugging#/runtime/this-firefox → Load Temporary Add-on → pick manifest.json.
Load unpacked / temporary add-on.

Tweak

Extension name

Tagline

Source

{
  "manifest_version": 3,
  "name": "JSON Lab",
  "description": "JSON utilities",
  "version": "1.0.0",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_title": "JSON Lab",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png"
    },
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "[email protected]",
      "strict_min_version": "121.0"
    }
  }
}