The best Shopify spy tools, compared fact by fact

How we compared these Shopify spy tools

On October 26, 2026 we read each tool's own public pages: its homepage, its pricing page and, where it had one, its API, MCP or extension page. We did not use review sites, and we did not test paid accounts. Every entry below links to the pages we read.

For each tool we noted the same facts:

• where it starts: the one store you open, or a search across many stores;
• its sales estimate, the traffic it shows, and the apps and theme it detects;
• the ads it shows next to a store;
• a browser extension, a public API and an MCP server for AI agents;
• a free plan, a free tool or a trial.

"Not stated" means we did not find the fact on the tool's own pages. It does not mean the tool lacks it. We leave out other tools' prices, which change often and depend on the billing period: each entry links to the tool's pricing page where it has one, read on the same day. Commerce Inspector, still named in older lists, is not here: on October 26, 2026 its address sent visitors to a shinecommerce.com page that returned a 404, and the shinecommerce.com homepage showed "Site Not Found".

The best Shopify spy tools side by side

The first table shows the store data each tool lists. The second shows how you reach that data and how you can start.

The Shopify spy tools, one by one

In alphabetical order. Each entry says what the tool lists, where it stops, and which pages we read on October 26, 2026.

Brandsearch

Brandsearch is a brand research platform with a free Chrome extension. On a Shopify store, its extension page says, the extension detects the products and ads and shows sales data and active ads, with no card needed. The web app adds a brand library: revenue modelled from traffic with a floor and a ceiling, traffic by country, products, tech stack, landing pages, emails, Meta, TikTok and Google ads, and Instagram posts. Its pricing page lists API and MCP calls on every plan, and its MCP page describes one hosted MCP server next to a REST API. We found no free plan, and its "Try for free" buttons give no trial length.

Best for: one store's sales and ads while you browse, then brand research with emails and landing pages.

Read: brandsearch.co, its pricing page, its MCP page and its extension page, checked on October 26, 2026. In detail: SellWinners vs Brandsearch.

BuiltWith

BuiltWith finds the technologies behind websites, Shopify stores among them. Its plans page says it is "free to use for individual site lookups forever". Every subscription includes alerts when sites start or stop using a technology, estimated sales revenue for e-commerce websites, lists of people publicly listed with businesses within GDPR limits, and APIs, MCP tools and SDKs for AI agents. Its homepage links to browser extensions. We found no traffic or ad data.

Best for: what a store is built with, and lists of the sites that use a platform or an app.

Read: builtwith.com and its plans page, checked on October 26, 2026.

Koala Inspector

Koala Inspector is a free Chrome extension for the Shopify store you are on. Its page lists the store's best-selling products and full product list, its installed apps, its active theme, estimated monthly sales, and estimated visitors with their channel mix, sources and geography. It shows the ad campaigns a store runs, without naming the ad platforms, and exports to CSV or Excel. The site adds leaderboards, such as the biggest stores and best sellers of the week, and tools such as a Shopify Sales Tracker and a Revenue Calculator. The Free plan gives 15 tokens a month with no card; Premium gives 220 tokens and tracks up to 50 stores. We found no API or MCP server.

Best for: a free look at one store's apps, theme, best sellers and traffic, right in the browser.

Read: the Koala Inspector page and its pricing page, checked on October 26, 2026. In detail: SellWinners vs Koala Inspector.

PPSPY

PPSPY searches Shopify stores and tracks their sales. Its homepage offers a 15-day sales report on a competitor, with order data its AI algorithm estimates, and store filters for revenue, keywords, traffic sources, paid ad platform, region or language, and the pixel, theme and apps installed. It has a Chrome extension and a free trial with no card. Its Open API returns stores, products and an ad library, billed in credits per record, plus ad and sales monitoring billed per monitor for a month. Its MCP page sets up a local server, started with npx, for Claude Desktop, Claude Code, Cursor, Codex and VS Code, and names Facebook ads among its data. We found no prices: its pricing address returned a 404.

Best for: searching stores by theme, app or pixel, and following a competitor's sales.

Read: ppspy.com, its API page and its MCP page, checked on October 26, 2026.

SellWinners

SellWinners is our product, and it starts from the Shopify stores we track. Search them by name, domain, product name or words on the storefront, then narrow the list with 52 filters, among them monthly visits, 30-day growth, estimated sales, units sold, active ads, and the apps, pixels and themes installed. A store's page shows its traffic history and top countries, estimated monthly sales with a low and a high figure, best sellers, apps, theme and pixels, social followers, its Meta and Google ads and its TikTok posts, and the stores most like it. For any store, tracked or not, the store check on Explore's Lookup page says whether it runs on Shopify, its theme and its apps. Over the API:

# Whether a store runs on Shopify, and its theme
curl "https://api.sellwinners.com/v1/tools/shopify-theme?url=allbirds.com" \
  -H "Authorization: Bearer YOUR_API_KEY"

GET /v1/tools/shopify-theme Parameters and fields in the docs

What it does not do: it has no browser extension, no TikTok Shop data and no contact details, and a search keeps to the stores we track. The Free plan needs no card: in the web app you find a store by domain and open its overview. The Free plan includes the web app and the MCP server (150 credits a month), without the API. Paid plans start at €39 a month.

Best for: finding stores across a niche by sales, growth, ads and tech, then reading one store with its ads. See the Shopify spy tool and Shopify store analytics.

ShopHunter

ShopHunter centers on Shopify stores and their products. Its homepage shows a store's estimated revenue, order volume and average product pricing, its best sellers, hourly product updates on the stores you track, and alerts when new product trends appear. Product filters are sales velocity, store size, price point and product age. For ads it names Facebook only, and it says browsing ads by product revenue is on Shophunter Pro. It shows a "Free Demo" option but no trial or prices, and its pricing address returned a 404. We found no API, MCP server or extension.

Best for: watching the products and prices of the stores you track, hour by hour.

Read: shophunter.io, checked on October 26, 2026.

Similarweb

Similarweb measures the traffic of any website; its pricing page does not mention Shopify. Its free website pages show, without signing in, a site's rank, visits, engagement, top countries and top traffic sources, and a company's annual revenue range. Business packages are priced through its sales team, and it also sells self-service packages for individuals, entrepreneurs and small teams. The API comes with its business packages or on its own. Its MCP server at mcp.similarweb.com needs a subscription with API access, and its tools cover traffic, channels, geography, ad networks, paid search spend and the technologies a site uses. We found no monthly store sales estimates.

Best for: how much traffic a store gets and where it comes from, free at a high level.

Read: its pricing page, a free website page and its MCP docs, checked on October 26, 2026.

StoreLeads

StoreLeads is a database of online stores for lead generation, written for marketing agencies and app developers who sell to merchants. It covers stores on 415 e-commerce platforms, Shopify among them, with each store's estimated monthly sales, employee count, apps with their install history, theme, technologies, social followers, phone numbers and non-personal emails. Its homepage shows no traffic or ad data. API and MCP access start on the Pro plan, every plan includes a Chrome extension, and a free account gives a limited preview.

Best for: lists of stores by app, theme, platform or country, with contact details.

Read: storeleads.app, with its plans on the same page, checked on October 26, 2026.

Winning Hunter

Winning Hunter covers brands, stores, ads and products, and says it tracks competitors' emails too. Its Store Tracker shows a store's daily revenue and traffic and suggests similar stores; the Basic plan tracks 25 stores. For ads, Basic lists Facebook ads and TikTok Shop, and the Standard plan adds TikTok and Pinterest ads. Its homepage does not mention apps, themes or an extension. Its docs describe a REST API and an MCP server with twenty tools on one key, for Claude, ChatGPT, Cursor, Gemini and n8n, without saying which plans include them. The free trial needs no card.

Best for: stores, ads and TikTok Shop in one account, with an API and an MCP server.

Read: winninghunter.com, with its plans on the same page, and its developer docs, checked on October 26, 2026. In detail: SellWinners vs Winning Hunter.

ZIK Analytics

ZIK Analytics sells eBay plans and a separate Shopify plan. Its Shopify spy page describes a Store Finder that searches stores by keyword or niche and filters them by revenue, sales and country, and a Sales Tracker with daily refreshed sales and revenue estimates for any public store (today, yesterday and the last 7 days), with its best sellers, new products, and detected apps and marketing channels. Its Shopify spy page lists Facebook, Instagram and TikTok ad coverage, while its pricing page names Facebook and Instagram ads for the Shopify plan, which also adds AliExpress and Alibaba supplier search. A theme detector is among its free tools. Its pricing FAQ mentions a 7-day trial, which its pricing page sells rather than gives free. We found no visit counts, API or MCP server, and its Chrome extension is for eBay.

Best for: a store's sales and best sellers over the last few days, with suppliers in the same plan.

Read: its Shopify spy tool page and its pricing page, checked on October 26, 2026.

Free ways to spy on a Shopify store

A store's own pages tell you a lot before you open any tool. Open the store, then its page source (Ctrl+U on Windows, Cmd+Option+U on a Mac).

• The theme and apps. The page source names the theme and many Shopify apps, in the files the store loads.
• The products and prices. On many stores, /products.json after the domain returns the catalog as data, and /collections/all?sort_by=best-selling lists the products in the store's own best-selling order. Both worked on two of the three stores we tried on October 26, 2026; a store can be set up so that they do not.

Free tools go further: Koala Inspector's free plan and the Brandsearch extension read a store as you browse, BuiltWith lists its technologies, and Similarweb's free pages show its traffic, while the SellWinners Free plan finds it by domain and opens its overview. For the ads a brand runs on Facebook and Instagram, see how to use the Facebook Ad Library. For a full teardown, see how to analyze any Shopify store.

Sales estimates: read them as ranges

No spy tool sees a store's orders, which sit in its Shopify admin, so every outside sales figure is an estimate. Koala Inspector calls its figure estimated monthly sales, Brandsearch models revenue from traffic with a floor and a ceiling, PPSPY says its AI algorithm estimates order data, and ShopHunter and ZIK Analytics call their figures estimates. In SellWinners, a store's page shows a low and a high figure under its estimated monthly sales. Read these numbers as a range, compare stores inside one tool rather than across tools, and trust a trend over several weeks more than one reading. See our FAQ on estimates and how much a Shopify store makes.

Which Shopify spy tool fits which job

• Check one store while you browse. Koala Inspector (free plan) and the Brandsearch extension read the store you are on, and PPSPY has a Chrome extension too. SellWinners has no extension: look the store up by its domain in Explore.
• Find stores across a niche. SellWinners filters the stores it tracks by sales, growth, ads, apps and theme, PPSPY by revenue, traffic sources, ad platform, pixel, theme and app, and ZIK Analytics finds them by keyword or niche. See the Shopify spy tool.
• Follow a competitor over time. Koala Premium tracks up to 50 stores, ShopHunter updates the products of the stores you track every hour, Winning Hunter's Store Tracker gives daily revenue and traffic, and PPSPY tracks a competitor's sales. SellWinners keeps each store's traffic and sales history and can track a brand's ads. Our guide to e-commerce competitor analysis shows what to check each week.
• Stores to sell to. StoreLeads and BuiltWith cover more platforms than Shopify and add contact details, which SellWinners does not have.
• A store and its ads together. Brandsearch, Winning Hunter and SellWinners show a store next to its ads on more than one network. For ads on their own, see the best ad spy tools.
• Data in your own code or AI agent. BuiltWith, Brandsearch, PPSPY, Similarweb, StoreLeads (from Pro), Winning Hunter and SellWinners document an API and an MCP server. See the ad library MCP servers for the ad side.

Before you pay, look up the same store, ideally one whose numbers you know, in two or three tools and compare what comes back. For SellWinners, the plans and their prices are on one page, Free included. Looking for products rather than stores? See the best dropshipping product research tools.

Brandsearch, BuiltWith, Koala Inspector, PPSPY, ShopHunter, Similarweb, StoreLeads, Winning Hunter, ZIK Analytics and Shopify are trademarks of their owners. SellWinners is not affiliated with any of them.