Free website tool
Free Website Speed Test
MerchantFrame's free Website Speed Test checks one public website URL with a mobile-first Lighthouse score, lab metrics, prioritized recommendations, and real visitor data when available. You can test Shopify stores and other publicly accessible websites.
No login No site admin access No credentials
Test a public website
Enter the complete public website URL, including https://.
Lighthouse performance
Largest Contentful Paint
Cumulative Layout Shift
Total Blocking Time
Speed Index
Real visitor data
Prioritized improvements
What should I fix first?
Start with the highest-priority recommendations shown in your result. Address primary-content loading first, then review heavy scripts, third-party code, render-blocking resources, oversized media, unnecessary page weight, and layout instability where they apply. Make one meaningful change at a time and test again instead of trying to optimize every warning at once.
On Shopify, common examples include heavy theme sections, theme JavaScript, app embeds, and third-party apps. These are Shopify examples; the recommendations also apply to WooCommerce and other public websites through their equivalent templates, plugins, scripts, and media.
How the Website Speed Test works
A website speed test measures the loading and interaction performance of a public page. MerchantFrame tests one complete public HTTP or HTTPS website URL at a time, including Shopify stores and other public websites.
In production, MerchantFrame sends that public URL to Google PageSpeed Insights for a Lighthouse lab run and separately checks Chrome UX Report for real visitor data when available.
The first test uses the mobile strategy. Desktop testing is a separate request, and its result can differ because it uses a different Lighthouse strategy.
A single Lighthouse run is a snapshot. Results can change with network conditions, storefront content, theme code, and third-party scripts.
What the test measures
The Lighthouse result is a controlled lab snapshot. It includes a performance score, First Contentful Paint, Largest Contentful Paint, Cumulative Layout Shift, Total Blocking Time, and Speed Index.
Real visitor data comes from Chrome UX Report and summarizes eligible Chrome experiences. Interaction to Next Paint appears only when valid real visitor data exists. Lab and real visitor measurements are labeled separately and are not interchangeable.
The Lighthouse performance score is not a Google ranking score, a complete SEO audit, or a complete Core Web Vitals assessment. Recommendations identify practical starting points, not guaranteed ranking, conversion, or performance outcomes.
How to interpret your speed test result
The Lighthouse Performance score is a diagnostic summary from one controlled lab run. MerchantFrame labels scores from 90 to 100 as Good, 50 to 89 as Needs improvement, and 0 to 49 as Poor. The score can change between runs and does not guarantee a Google ranking outcome.
Lab data measures a page under controlled conditions, which makes it useful for reproducing performance bottlenecks. Real visitor data (field data) summarizes aggregated eligible Chrome experiences when Google has enough information. The two can differ because visitors use different devices, networks, locations, and page states from the controlled lab run.
Use the lab result and prioritized recommendations to identify changes you can test now. Use real visitor data, when available, to understand how eligible visitors experienced the page over its reported collection period.
- First Contentful Paint
- How quickly the first visible text or image appears.
- Largest Contentful Paint
- How quickly the largest primary piece of visible content appears.
- Cumulative Layout Shift
- How visually stable the page remains without unexpected layout movement.
- Total Blocking Time
- How much lab-measured main-thread blocking can delay interaction.
- Speed Index
- How quickly visible page content fills the screen during the lab run.
- Interaction to Next Paint
- Real visitor responsiveness shown only when valid real visitor data is available.
Website Speed Test FAQ
Is this the same as real visitor performance?
No. Lighthouse is a controlled lab snapshot. Chrome UX data, when available, summarizes real visitor experiences.
Why is real visitor data unavailable?
Google may not have enough eligible Chrome UX data for every URL or origin. Missing real visitor data does not prevent a complete Lighthouse result.
Does the test change my website?
No. It uses the public URL and does not access an admin area or modify website content.
Can I run a desktop test?
Yes. Complete the mobile-first test, then use the separate desktop action in the result.
Privacy and test limitations
Submit only a public website URL. The test does not require a login, site admin access, credentials, or permission to change the website. Do not submit private or authenticated URLs.
In production, the submitted public URL is sent to Google PageSpeed Insights and, when available, Chrome UX Report. MerchantFrame does not put the submitted URL in the page address, browser history, browser storage, or GA4.
GA4 does not receive the website URL, numeric score, performance metrics, recommendations, raw responses, or free-text values from the speed test.
- The test reads public performance data and does not modify the website.
- Results can vary between runs and should be treated as snapshots.
- Real visitor data may be unavailable, while the Lighthouse result remains complete.
- Desktop testing is a separate request from the mobile-first result.
- The result is not a guarantee of search ranking, conversion, or future performance and is not a substitute for professional diagnostics.