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Tool Comparison

PageDiag vs Google PageSpeed Insights: Which Ecommerce Audit Tool Is Right for You?

Google PageSpeed Insights (PSI) is the go-to free tool for checking Core Web Vitals. It provides lab data from Lighthouse and real-user data from the Chrome UX Report. However, PSI is entirely generic - it has no understanding of ecommerce, cannot detect your platform, and provides the same recommendations for a store doing £1M/year as it does for a hobby blog. PageDiag builds on Core Web Vitals data and adds ecommerce-specific layers that PSI simply does not have.

Feature Comparison

Speed Testing
Core Web Vitals with ecommerce scoring
Core Web Vitals (lab + field data)
Ecommerce Detection
Auto-detects Shopify, WooCommerce, Magento, etc.
No platform awareness
Widget Health
Detects and scores third-party widget impact
Flags third-party code generically
Review Compliance
CMA/FTC review compliance checking
Not available
AI Shopping Score
Scores readiness for AI shopping assistants
Not available
LLM Visibility
Checks how LLMs see your product pages
Not available
PDF Reports
Branded PDF export
No export (screenshot only)
Monitoring
Scheduled monitoring with alerts
No monitoring
Price
Free tier with paid upgrades
Completely free

Where Google PageSpeed Insights Falls Short for Ecommerce

  • 1PageSpeed Insights provides generic recommendations like "reduce unused JavaScript" without telling you which Shopify app or WooCommerce plugin is responsible. For store owners, this makes the advice difficult to act on.
  • 2No ecommerce platform detection means PSI cannot provide platform-specific guidance. The difference between optimising a Shopify store and a Magento store is significant, but PSI treats them identically.
  • 3PSI has no concept of widget health - it might flag a chat widget as "third-party code" but cannot tell you if the widget is actually broken, rendering incorrectly, or failing to load.
  • 4No review compliance analysis. As regulations around fake reviews tighten globally, PSI offers no help in checking whether your review displays meet legal requirements.
  • 5No AI shopping readiness scoring. As AI assistants become a major product discovery channel, PSI provides no insight into how well your pages are structured for AI consumption.
  • 6No report export or monitoring capabilities. Every check is a one-off manual process with no way to track changes over time or receive alerts when performance degrades.

Why Ecommerce Stores Choose PageDiag

PageDiag identifies your ecommerce platform and provides tailored recommendations. Instead of "reduce unused JavaScript", you get "the Klaviyo app adds 340KB of JavaScript - consider lazy-loading it".
Widget health analysis checks whether your third-party tools (reviews, chat, loyalty programs) are actually working correctly, not just whether they impact load time.
Review compliance checking scans your store against CMA and FTC guidelines, flagging issues like unverified review badges, suspicious review patterns, and non-compliant display formats.
AI Shopping Score evaluates your product structured data, pricing markup, and availability signals to determine how well AI shopping assistants can understand and recommend your products.
PDF report export lets you share results with developers, agencies, or stakeholders without requiring them to visit the PageDiag website.
Scheduled monitoring tracks your store performance over time and sends alerts when key metrics degrade, so you catch problems before they impact revenue.

Frequently Asked Questions

Is PageDiag more accurate than Google PageSpeed Insights?

Both tools measure Core Web Vitals accurately. The difference is context. PageSpeed Insights gives you raw numbers and generic advice. PageDiag gives you the same performance data plus ecommerce-specific analysis - platform detection, widget health, review compliance, and AI shopping readiness. For an online store, PageDiag provides significantly more actionable information.

Should I use PageSpeed Insights or PageDiag?

If you run an ecommerce store, use PageDiag. It includes everything PageSpeed Insights offers plus ecommerce-specific features. If you are optimising a non-ecommerce website, PageSpeed Insights is a solid free option. Many store owners use both - PSI for a quick Core Web Vitals check and PageDiag for the full ecommerce diagnostic.

Does PageDiag use Lighthouse like PageSpeed Insights?

PageDiag performs its own comprehensive analysis that covers Core Web Vitals and goes beyond what Lighthouse measures. While Lighthouse focuses on general web performance, PageDiag adds ecommerce platform detection, widget health scoring, review compliance, and AI shopping readiness - metrics that Lighthouse does not include.

Can PageDiag export reports like PageSpeed Insights?

PageDiag offers branded PDF report export, which PageSpeed Insights does not provide. This is particularly useful for agencies reporting to clients or store owners sharing performance data with their development team.

Is Google PageSpeed Insights enough for my Shopify store?

PageSpeed Insights tells you your store is slow but not why in ecommerce terms. It cannot identify which Shopify apps are causing problems, whether your review widget is compliant with regulations, or how AI shopping assistants see your products. For a complete picture of your store health, you need an ecommerce-specific tool like PageDiag.

Other Comparisons

PageDiag vs GTmetrix

Generic speed testing vs ecommerce-focused diagnostics

PageDiag vs Pingdom

Uptime monitoring vs ecommerce performance diagnostics

PageDiag vs WebPageTest

Developer-focused testing vs actionable ecommerce insights

PageDiag vs Lighthouse

Raw audit data vs actionable ecommerce intelligence

Try PageDiag Free - See the Difference

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