Browser StudioBrowser Studio

Free tool

Chrome extension Manifest V3 generator

Build a valid manifest.json from a simple form. Pick permissions, set your service worker, and get a clean Manifest V3 file — with inline warnings for the permissions that scare users away.

manifest.json

{
  "manifest_version": 3,
  "name": "My Extension",
  "version": "1.0.0",
  "permissions": [
    "storage"
  ],
  "background": {
    "service_worker": "background.js"
  }
}

How it works

From form to manifest in three steps.

  1. 01

    Fill in the basics

    Name, version, description, and your background service worker file.

  2. 02

    Pick permissions

    Toggle the permissions you need — flagged ones trigger a strong install warning.

  3. 03

    Copy or download

    Drop the generated manifest.json straight into your project root.

FAQ

Manifest V3, explained.

manifest.json is the required configuration file at the root of every Chrome extension. It declares the name, version, permissions, background service worker, and entry points. Chrome reads it to know what your extension is and what it's allowed to do.

Manifest V3 replaces background pages with a service worker (background.service_worker), splits permissions into permissions and host_permissions, uses the action key instead of browser_action/page_action, and requires declarativeNetRequest instead of blocking webRequest. This generator outputs MV3 by default.

Request the minimum you need. Permissions like tabs, history, management, and broad host permissions (<all_urls>) trigger a strong install warning — this tool flags those inline. Fewer scary warnings means more installs and fewer uninstalls.

Only if your extension reads or changes page content or network requests on specific sites. Use the narrowest pattern that works (for example https://*.example.com/* instead of <all_urls>) to reduce the install warning.

A scary permission prompt is one of the most common reasons users abandon an install or uninstall shortly after. Keeping your manifest lean builds trust — and when users do leave, UserFeed's uninstall feedback tells you whether permissions were the reason.

Shipped it? Now learn why users leave.

A lean manifest gets the install. UserFeed tells you what happens next — a branded uninstall feedback form and drop-off funnel, free for one extension.

Explore UserFeed