Best Shopify Spy Tools in 2026 [Honest Guide + 4,898-Store Data]

TL;DR: Most Shopify spy tools claim 70-80% accuracy on sales estimates. The real number is closer to 30-50%. We compared 10 tools based on features, pricing, and 250,000+ user reviews. Best overall: Koala Inspector (4.6/5, 250k users). Best free: Store Inspector. Best for ad research: BigSpy. Skip the fake sales numbers - focus on tech stack signals instead.

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You want to spy on Shopify competitors. Maybe you're researching products to sell. Maybe you're an agency qualifying leads. Maybe you're a store owner checking what successful competitors use.

Here's what most guides won't tell you: spy tools can't show you exact sales numbers. The tools claiming "80% accuracy" are measuring something different than you think - and the real accuracy for revenue estimates is much lower.

This guide is different. We'll be honest about what spy tools can and can't do, compare 10 popular options based on real user data, and show you what actually matters for competitor research - backed by our analysis of 4,898 Shopify stores.

The Uncomfortable Truth About Spy Tool Accuracy

Every Shopify spy tool promises accurate sales data. PPSPY claims "80.5% accuracy." Others claim 70-85%. These numbers are misleading.

Why spy tools can't show accurate sales:

The problem is simple. Spy tools watch a public page that shows when products were last updated. When something sells, the inventory changes, which updates a timestamp.

But here's what they can't actually see:

As one honest analysis put it: "If a store is doing multiple orders per second, there's just no way in which one can do this accurately."

Realistic accuracy expectations:

This isn't a flaw with specific tools - it's how all of them work. No spy tool can see inside Shopify's database. They're all making educated guesses.

What this means for you: Use spy tools to get a general sense of size (bigger vs. smaller, growing vs. declining) rather than exact numbers. Focus on signals you can verify - like tech stack and apps.

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What Actually Predicts Store Success [Original Data]

We analyzed 4,898 Shopify stores across 18 categories. Instead of chasing fake sales numbers, here's what actually separates successful stores from struggling ones.

App Count Correlates with Revenue

Stores invest in apps as they grow. A store paying $500/month for Klaviyo + Gorgias + Rebuy isn't doing $10k/month - they couldn't afford it.

Key insight: App count increases with traffic until stores hit scale, then levels off. Bigger stores don't add more apps - they pick better ones.

Specific Apps Signal Revenue Tiers

Some apps are too expensive for small stores. Seeing these installed tells you more than any sales estimate:

Pixel Count Shows Ad Investment

We found pixel count correlates with advertising budget:

A store running Meta Pixel + TikTok Pixel + Google Ads + Pinterest Tag + Snapchat Pixel is spending serious money on ads. That means serious revenue.

Real example: Brooklinen runs 6+ pixels, uses Klaviyo, Gorgias, Yotpo, and Rebuy. Even without checking any spy tool's revenue estimate, you know from their stack alone they're doing $10M+/year. The tech doesn't lie.

The takeaway: Instead of trusting fake sales numbers, look at tech stack signals. A store with Klaviyo + Gorgias + 6 pixels is doing well - regardless of what a spy tool claims their revenue is.

For deeper analysis, see our guides on what apps top Shopify stores use and how to check Shopify store revenue.

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10 Best Shopify Spy Tools Compared

We evaluated these tools based on features, pricing, user reviews, and honest limitations. No fake accuracy claims - just what each tool actually does well.

Quick Comparison

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1. Koala Inspector

Best for: All-around Shopify store analysis

Koala Inspector is the most popular Shopify spy Chrome extension with over 250,000 users. It gives you a solid overview of any Shopify store - theme, apps, traffic estimates, and best-selling products.

What it detects:

• Theme name and type
• Installed apps
• Traffic estimates
• Best-selling products
• Facebook/TikTok ads
• Store age and product count

Strengths:

• Large user base and consistent updates
• Good free tier for basic research
• Covers multiple data points in one tool
• Clean, usable interface

Limitations:

• Traffic estimates are rough (like all tools)
• Sales estimates should be treated as directional only
• Some features locked behind paid tiers
• Must reopen after switching tabs

What users say:

• "Great for quick store analysis"
• "Free version is useful, Pro adds depth"
• "Traffic numbers don't always match other sources"

Best for: Store owners and dropshippers who want a single tool for basic competitor research.

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2. Store Inspector

Best for: Tech stack analysis and lead qualification

Store Inspector is our free Chrome extension focused on what matters most: detecting the apps, themes, and pixels that signal store success.

What it detects:

• Theme name and type (free/paid/custom)
• Installed apps with categories
• Tracking pixels (Meta, TikTok, Google, etc.)
• Traffic tier estimation
• Shopify Plus detection
• Payment providers

Strengths:

• Completely free, no feature gating
• Focus on verifiable signals (apps, pixels, themes)
• Fast, lightweight detection
• No fake sales estimates

Limitations:

• Doesn't estimate revenue (by design - we don't trust those numbers)
• Newer tool with smaller user base
• Extension only (no web dashboard yet)

Our philosophy: We built Store Inspector to focus on signals you can actually verify. We don't show sales estimates because we know they're unreliable. Instead, we show tech stack signals that correlate with success based on our 4,898-store analysis.

Best for: Agencies qualifying leads, store owners researching competitors' tech stacks, and anyone who wants accurate detection over fake metrics.

Install Store Inspector (Free) →

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3. PPSPY

Best for: Dropshipping product research

PPSPY markets itself as an AI-powered Shopify spy tool with sales tracking. It's popular in the dropshipping community for product research.

What it claims to detect:

• Daily sales estimates (claims 80.5% accuracy)
• Best-selling products
• Traffic sources
• Facebook/TikTok ads
• Store revenue estimates

Strengths:

• Large database of tracked stores
• Product-level insights
• Ad creative library
• Filtering by niche, revenue, traffic

Limitations:

• Accuracy claims are disputed by users
• No paid plan = very limited access
• Sales estimates face the same technical limitations as all tools
• Higher price point than alternatives

What users say:

• Mixed reviews on data accuracy
• "Good for finding products, skeptical of sales numbers"
• "Interface can be overwhelming"
• Some report "PPSPY fatigue" from unreliable data

Reality check: PPSPY claims 80.5% accuracy, but this measures something different than most users expect. It's detecting changes in product data, not actual revenue. Treat their numbers as rough estimates, not facts.

Best for: Dropshippers researching winning products who understand the accuracy limitations.

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4. BuiltWith

Best for: Deep technology lookup (when you need everything)

BuiltWith is the heavyweight of tech detection. While most tools show you what a site uses now, BuiltWith shows you what they used before - which is surprisingly useful.

Want to know when a competitor switched from Mailchimp to Klaviyo? BuiltWith tracks that. Want to see that Gymshark added Attentive for SMS marketing in 2023? It's in there.

The catch: It's expensive. At $295/month, it only makes sense if you're doing research at scale or need the API for automation. For checking individual stores, it's overkill.

When it's worth it:

• Building lead lists by technology (e.g., "all Shopify stores using Klaviyo")
• Tracking when competitors adopt new tools
• Agency sales teams who need this data daily

Skip it if: You just want to check a few competitors. Use Store Inspector or Wappalyzer instead.

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5. SimilarWeb

Best for: "How big is this competitor, really?"

SimilarWeb answers the question every competitor researcher asks: how much traffic do they actually get?

It's the closest thing to accurate traffic data you'll find. When we say Allbirds gets ~3M monthly visits, that number probably came from SimilarWeb. It's what investors, journalists, and analysts use.

What makes it useful:

• See where traffic comes from (40% paid ads? 60% organic? That tells you their strategy)
• Compare competitors side-by-side
• Track traffic trends over time

The accuracy question: For stores over 100k monthly visitors, SimilarWeb is usually within 30% of real numbers. For smaller stores under 50k? It can be 50%+ off. Use it for relative comparison ("Store A is bigger than Store B") not exact numbers.

Free tier reality: You get 5 results per day. Enough to check a few competitors, not enough for serious research.

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6. BigSpy

Best for: "What ads are actually working?"

BigSpy doesn't care about themes or apps. It cares about ads. And if you're running paid traffic, that's exactly what you need.

The real value: finding ads that have been running for months. If a competitor has run the same ad for 6+ months, it's profitable. That's more useful than any sales estimate.

How to actually use it:

1. Search your niche (e.g., "sustainable clothing")
2. Filter by "Running days" > 30
3. Sort by engagement
4. Study the winners

Ads that survive 30+ days are beating the algorithm. Study their hooks, their creative style, their landing pages.

The database is massive: 1 billion+ ads across Facebook, Instagram, TikTok, Pinterest, and YouTube. The free tier gives you limited searches but enough to get inspired.

Skip it if: You don't run paid ads. This tool is 100% focused on advertising.

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7. Commerce Inspector

Best for: Price monitoring (but showing its age)

Commerce Inspector was one of the original Shopify spy tools. It still works, but it hasn't kept up with newer competitors.

What it does well: Price tracking. If you want alerts when a competitor changes their pricing, Commerce Inspector handles that. Pick a store, track it, get notified when prices change.

The problem: Once you subscribe to a store, you're locked in for 30 days. Can't swap it for a different competitor. The interface feels like 2019. And users report it's less actively maintained than it used to be.

Honest take: Unless you specifically need price monitoring alerts, newer tools like Koala Inspector do most of what Commerce Inspector does - and more.

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8. Wappalyzer

Best for: Tech detection that just works

Wappalyzer has 2 million users for a reason: it's dead simple. Visit any website, click the icon, see what technologies they use. Done.

Why developers love it: It works on everything - not just Shopify. WordPress, custom builds, Magento, whatever. The detection is accurate and the free tier is genuinely useful.

What it won't tell you: Anything ecommerce-specific. No best sellers, no traffic estimates, no sales data. It's purely "what tech is this site running?"

Pro tip: Pair Wappalyzer (for general tech) with Store Inspector (for Shopify-specific data). Wappalyzer catches things like CDNs and security tools that Shopify-specific tools miss.

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9. FindNiche

Best for: Dropshippers who want everything in one place

FindNiche is built specifically for dropshippers. It combines store analysis, product research, and ad tracking - all focused on finding products to sell.

The dropshipper workflow:

1. Find trending products in their database
2. See which Shopify stores sell them
3. Check the ads those stores run
4. Find the product on AliExpress
5. Import to your store

It's a complete pipeline. If you're doing classic dropshipping (AliExpress → Shopify), FindNiche is purpose-built for that.

Not for everyone: If you're a brand, agency, or selling your own products, FindNiche's features won't apply. It's dropshipping-focused by design.

Same accuracy caveats: Their sales estimates face the same technical limits as every other tool. Don't trust the revenue numbers.

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10. SEMrush

Best for: When you need the full marketing picture

SEMrush isn't a Shopify spy tool - it's a marketing intelligence platform. But if you want to understand how competitors actually grow, it's unmatched.

What it actually tells you:

Take a store like Ridge Wallet. SEMrush shows you:

• They rank for 50,000+ keywords
• Their top pages drive 200k+ organic visits/month
• They've built 15,000+ backlinks
• Their paid ads target these specific terms

That's the kind of insight that explains how a competitor got big - not just that they are big.

The cost question: At $139/month minimum, SEMrush only makes sense if you're doing serious marketing. For quick competitor checks, it's overkill. For building an SEO or content strategy, it's worth every dollar.

What it won't show: Shopify-specific data. No themes, no apps, no pixels. Pair it with a Shopify-focused tool for the complete picture.

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Best Tool By Use Case

Different goals need different tools. Here's what we recommend:

For Agency Lead Generation

Best choice: Store Inspector (free) + StoreInspect database

Why: You need to quickly qualify leads based on tech stack gaps. A store without Klaviyo is an email marketing opportunity. A store without reviews app is a conversion opportunity. Focus on signals, not fake revenue numbers.

Our guide to finding Shopify clients covers the full workflow.

For Dropshipping Product Research

Best choice: Koala Inspector + BigSpy

Why: Koala gives you store-level insights (best sellers, apps), BigSpy shows what ads are working. Skip the sales estimates - look at ad longevity instead. An ad running for 6+ months is profitable.

For Store Owner Competitive Research

Best choice: Store Inspector + SimilarWeb (free tier)

Why: Understand what apps successful competitors use (Store Inspector) and roughly how much traffic they get (SimilarWeb). Focus on tech stack patterns, not revenue guesses.

See our competitor analysis guide for the full methodology.

For Marketing/SEO Analysis

Best choice: SEMrush or Ahrefs

Why: These tools actually have accurate data for what they measure (keywords, backlinks, rankings). Skip the Shopify-specific tools for marketing analysis.

Best Free Option

Best choice: Store Inspector (ours) or Koala Inspector's free tier

Why: Both are completely free for basic research. Store Inspector focuses on verifiable signals. Koala adds best-seller data but with accuracy caveats.

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What Spy Tools Can't Tell You

Let's be clear about limitations. No spy tool can accurately show:

What to do instead:

1. For revenue estimates: Use tech stack signals. A store running Klaviyo + Gorgias + Rebuy + 6 pixels is doing well - probably $100k+/month minimum.

2. For traffic estimates: Use SimilarWeb for directional comparison between competitors. Don't trust exact numbers.

3. For validation: Cross-check multiple sources. If SimilarWeb, spy tools, and social following all point to "big store," it's probably big.

4. For lead qualification: Focus on gaps in their stack, not revenue. A store missing email marketing is a lead regardless of their revenue.

See our revenue estimation guide for the full methodology, or browse stores by category to see real tech stack data.

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The Smarter Approach: Tech Stack Signals

Instead of chasing unreliable sales estimates, focus on tech stack signals that correlate with success.

Based on our 4,898-store analysis, here's what to look for:

Apps That Signal Growth Stage

See our guide on how to see what apps a Shopify store is using for detection methods.

Theme Signals

Learn more in our guide on how to detect what Shopify theme a store uses.

The Bottom Line

Spy tools are useful for understanding competitors at a directional level. But don't trust the revenue numbers. Focus on:

1. What apps they use (verifiable)
2. What theme they run (verifiable)
3. What pixels they have (verifiable)
4. Relative traffic levels (directional)
5. Ad creative longevity (verifiable)

These signals tell you more about a store's success than any fake sales estimate.

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FAQ

Do Shopify spy tools actually work?

For detecting themes, apps, and pixels - yes, they're reasonably accurate (70-95%). For sales and revenue estimates - treat them as rough directional signals, not facts. The technical limitations of timestamp tracking make exact sales data impossible.

Which Shopify spy tool is most accurate?

For technology detection (apps, themes): Wappalyzer and Store Inspector are highly accurate. For sales estimates: No tool is truly accurate - they all face the same technical limitations. Koala Inspector and PPSPY are popular but their sales numbers should be treated skeptically.

Can spy tools see my store's sales?

No. Spy tools can see product updates and estimate sales based on inventory changes, but they can't see actual order data. Multiple orders per second are impossible to track accurately. Your actual sales data is private.

Are Shopify spy tools legal?

Yes. They use publicly available data - your storefront is public, your product pages are public. They're not accessing private Shopify data. This is standard competitive intelligence.

How do I hide my store from spy tools?

You can't fully hide since your storefront is public. Some stores disable the JSON API endpoint, but this breaks some functionality. The best approach: accept that competitors can see your store just like you can see theirs.

How do I find Shopify stores without spy tools?

Use Google search operators. This finds Shopify stores in any niche for free:

site:myshopify.com "organic skincare"

Or find stores using specific apps:

site:myshopify.com "powered by Klaviyo"

See our full guide on how to find Shopify stores for 9 more methods.

Free vs paid spy tools - worth the upgrade?

For basic research, free tools like Store Inspector and Koala's free tier are sufficient. Paid tools add features like tracking over time, larger databases, and ad research. Worth it if you're doing research at scale.

Is PPSPY's 80.5% accuracy claim real?

It's measuring accuracy on detecting product changes, not revenue accuracy. The number is technically defensible but misleading. Revenue estimates from any tool are 30-50% accurate at best.

Koala Inspector vs PPSPY - which is better?

Koala Inspector has better user ratings (4.6 vs 3.9), more users (250k+), and a more reliable free tier. PPSPY offers more aggressive sales tracking features but with disputed accuracy. For most users, Koala is the safer choice.

What's the best free Shopify spy tool?

Store Inspector is completely free with no feature limits. Koala Inspector's free tier is also useful for basic analysis. Wappalyzer's free tier works for technology detection.

Can spy tools show competitor ad spend?

Not directly. They can show active ads (via Meta Ad Library integration) and estimate based on ad volume/longevity, but actual ad spend is private. A store running 50+ ad creatives for 6+ months is spending serious money - but the exact amount is unknown.

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Summary

Key takeaways:

1. Don't trust sales estimates. All spy tools face the same technical limitations. 30-50% accuracy is realistic.

2. Focus on verifiable signals. Apps, themes, pixels, and ad longevity tell you more than fake revenue numbers.

3. Use the right tool for the job. Koala for general research, Store Inspector for tech stack, BigSpy for ads, SEMrush for SEO.

4. Cross-check multiple sources. If multiple signals agree, you can be more confident.

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Want to analyze stores at scale?

StoreInspect has 4,898+ stores with verified tech stack data, traffic tiers, and founder contacts. Filter by category, apps, and growth signals - then export your leads.

Browse the Database →

Want to analyze any store for free?

Install Store Inspector - free Chrome extension. See apps, themes, pixels, and traffic tier in one click. No fake metrics.

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