Chrome Web Store & Firefox Add-ons Scraper — Users, Ratings

Scrape Chrome Web Store and Firefox Add-ons extensions in one run, in one table: users, rating and number of ratings, version, last update, size, languages, developer, website, support and privacy-policy links, permissions and site access, data-handling disclosures, store badges (Featured, Established publisher, Recommended) and more.

Find extensions by keyword, by category, by extension ID or link, or read the full catalog. Turn on Compare with the previous run and schedule it to track user growth, rating changes and new versions over time.

No login, no browser extension, no API key.

What can you use it for?

• Competitive intelligence — see how many users your competitors' extensions have, how they are rated, how often they ship updates, and track growth week by week.
• Market research — size a niche ("vpn", "password manager", "seo", "ai writing"): how many extensions, how many users, who leads, who is new.
• Lead generation for extension businesses — developer names, websites, support links and business contact details of companies that publish extensions (EU trader disclosures).
• Security and privacy reviews — the permissions, site access and declared data handling of the extensions your team uses, Manifest V2 vs V3, minimum browser version.
• Investors and analysts — spot fast-growing extensions and the publishers behind them across both stores.

How it works

You give	Chrome Web Store	Firefox Add-ons
Search terms	every extension whose name contains your words, from the store's public index of all ≈375,000 listings	Mozilla's own add-on search (by relevance or your sort)
Categories	the top 32 extensions of each category, as the store's category page shows them	every extension in the category (up to 25,000), most-used first
Extension IDs / links	kbfnbcaeplbcioakkpcpgfkobkghlhen or the store link	ublock-origin, the GUID, the numeric ID or the store link
Full catalog	every listing in the store's index	every extension of every category
Nothing	the top 32 of all 18 categories	the most-used extensions

Max extensions is shared fairly between your searches and categories, duplicates across sources are saved once, and every run ends with a plain-English status message (and a RUN_REPORT record) saying what was found.

Input

Field	What it does
Stores	Chrome Web Store, Firefox Add-ons, or both (default both)
Search terms	Keywords, e.g. vpn, grammar, seo, password manager
Chrome categories / Firefox categories	Pick from the stores' own category lists
Extension IDs or links	Specific extensions from either store (category links work too)
Full catalog	Scrape whole stores instead of a search (large runs take hours — raise Timeout)
Max extensions	Total for the run (default 100, 0 = no limit)
Full Chrome details	Read each Chrome extension's store page for the update date, size, languages, developer, links, data handling, description and screenshots (on by default)
Minimum users / Minimum rating / Updated within (days)	Keep only the extensions you want
Firefox sort	Most users, top rated, recently updated, newest, trending, most weekly downloads or relevance
Compare with the previous run	Adds the previous run's users / rating / version, the change in users, and whether the extension is new
Language	Language of names and descriptions (en, de, fr, ja, pt-BR …)

Example:

{
  "stores": ["chrome", "firefox"],
  "searchTerms": ["vpn"],
  "maxItems": 20
}

Output

One row per extension. A real row (Chrome, 2026-10-29, trimmed):

{
  "store": "chrome",
  "id": "kbfnbcaeplbcioakkpcpgfkobkghlhen",
  "name": "Grammarly: AI Writing Assistant and Grammar Checker App",
  "url": "https://chromewebstore.google.com/detail/kbfnbcaeplbcioakkpcpgfkobkghlhen",
  "type": "extension",
  "shortDescription": "Grammarly for Chrome helps you write with confidence. Get AI support for grammar, clarity, and tone, from first draft to final edit.",
  "category": "productivity/communication",
  "categoryLabel": "Communication",
  "users": 40000000,
  "rating": 3.87,
  "ratingCount": 43165,
  "version": "14.1343.0",
  "manifestVersion": 3,
  "minBrowserVersion": "98",
  "createdAt": "2012-10-22T10:17:01.775Z",
  "updatedAt": "2026-10-28T13:22:59.694Z",
  "size": "18.16MiB",
  "sizeBytes": 19042140,
  "languages": ["English"],
  "developer": "Grammarly",
  "developerEmail": "support@grammarly.com",
  "website": "http://grammarly.com/",
  "supportUrl": "https://support.grammarly.com/",
  "privacyPolicyUrl": "https://www.grammarly.com/privacy-policy",
  "isTrader": true,
  "traderName": "Grammarly, Inc.",
  "traderAddress": "548 Market St Ste 35410, San Francisco, CA 94104-5401, US",
  "traderPhone": "+16282338294",
  "dunsNumber": "031633083",
  "featured": true,
  "establishedPublisher": true,
  "badges": ["Featured", "Established publisher"],
  "permissions": ["scripting", "sidePanel", "tabs", "notifications", "cookies", "identity", "storage"],
  "hostPermissions": ["http://*/*", "https://*/*"],
  "optionalPermissions": ["nativeMessaging", "clipboardRead"],
  "dataHandling": ["Personally identifiable information", "Personal communications", "Location", "User activity", "Website content"],
  "detailsIncluded": true,
  "source": "Chrome extension ID",
  "scrapedAt": "2026-10-29T19:21:34.516Z"
}

Firefox rows have the same columns plus slug, guid, weeklyDownloads, reviewCount, license, tags and requiresPayment — e.g. uBlock Origin: 11,365,567 users, 242,069 weekly downloads, 4.8 from 22,260 ratings, version 1.75.0, badge "Recommended". Also in every row: description, icon, screenshots, source (which search, category or ID found it) and position. With Compare on: previousUsers, usersChange, previousRating, previousVersion, versionChanged, isNewSinceLastRun.

The dataset has two views: Overview and Permissions & data. Export to JSON, CSV, Excel or via the API.

Pricing

Pay per result — you only pay for what you get:

Event	Price	Per 1,000
Extension saved (either store)	$0.0012	$1.20
Chrome store page read (full details, or checking your filters)	$0.0015	$1.50
Listing that added nothing (a Firefox search page or Chrome category page with no new extension, a section of the Chrome index with no match, an ID the store doesn't know)	$0.0005	$0.50
Run start	$0.001	—

So 1,000 Firefox extensions cost $1.20, 1,000 Chrome extensions with full details $2.70, and 1,000 Chrome extensions from categories with "Full Chrome details" off $1.20. Listings that add extensions are paid for by those extensions only. A store that refuses or shows a bot check is never charged.

Tips

• Chrome search order: Chrome search terms are matched against the names in the store's public index, which is not sorted by popularity. To get all Chrome extensions for a word, set Max extensions high (or 0) and sort the dataset by users. Words match the start of a word in the first ~25 characters of the name: vpn finds "Free VPN for Chrome" but not "OpenVPN Connect" — add openvpn as a second term for that. A common word fills Max extensions in under a minute; a rare word is checked against the whole index, which takes 3–5 minutes.
• Top extensions of a niche on Chrome: pick the category — you get the store's top 32 by users, fast.
• Filters save money on Chrome categories: there, Minimum users and Minimum rating are checked before a store page is opened. Chrome search terms and the full catalog have to open each matching page to know its users, so with a high Minimum users every page that does not pass is still a "Chrome store page read" — set a maximum cost per run in the run options if you combine the two.
• Weekly tracking: schedule the same input with Compare with the previous run on; usersChange and isNewSinceLastRun show what moved.
• Firefox users are average daily users (Mozilla's figure); Chrome users are the rounded figure the store shows.
• Big runs: the full Chrome catalog is ≈375,000 store pages — raise the run Timeout to several hours.

FAQ

Is it legal to scrape the Chrome Web Store and Firefox Add-ons? This actor reads only public pages and Mozilla's public add-ons data that anyone can see without an account, it follows both stores' robots.txt rules, and it does not collect reviews or reviewers. Scraping publicly available data is generally lawful, but how you use the data is your responsibility — check the laws that apply to you (e.g. GDPR) and consult a lawyer if in doubt.

Does it access any private data? No. No login, no cookies, nothing behind an account. Developer contact details are limited to business contacts: an e-mail is kept only when it is a role mailbox (support@, info@, hello@ …), and a trader's legal name, address, phone and D-U-N-S number only when the trader is a company. Personal e-mail addresses and phone numbers in descriptions are removed.

Why does a Chrome category give only 32 extensions? That is what the store's category page shows (its top 32 by users). For more, use search terms or the full catalog.

Can I get reviews? No — review texts are not collected.

Why are some Chrome extensions without a developer name? Some developers publish with only an e-mail address; when that address is a personal one it is not included.

What happens if a store blocks the run? The run stops that store with a plain message and still finishes successfully with whatever was collected — you are not charged for refused requests.