Synthetic Monitoring Reports use Lighthouse™ (v.13.3.0).
Instead of a single proprietary score, every new report shows four separate scores, each reflecting a distinct quality dimension of your web page.
How is the Performance score calculated?
This score and all performance metrics in this report are based on the Lighthouse™ scoring methodology. For more information, read Lighthouse™ scoring documentation.
Powered by Lighthouse™ (v.13.3.0). Lighthouse source code is copyright by Google LLC and licensed under the Apache License, 2.0. Lighthouse is a trademark of Google LLC. This product is not affiliated with nor endorsed by Google.
The four audit scores
Performance
The Performance score measures how fast and smooth your page loads for users. It is calculated from a weighted combination of five lab metrics:
| Metric | What it measures |
|---|---|
| Largest Contentful Paint (LCP) | When the largest visible content element finishes loading |
| Total Blocking Time (TBT) | How long the main thread is blocked and prevents user interaction |
| Cumulative Layout Shift (CLS) | How much the layout unexpectedly shifts during loading |
| First Contentful Paint (FCP) | When the first content appears on screen |
| Speed Index | How quickly content is visually populated |
Learn more about Lighthouse™ Performance scoring.
Accessibility
The Accessibility score measures how easy your page is to use for people with disabilities. It checks for compliance with WCAG guidelines across areas such as:
- Color contrast between text and backgrounds
- Presence of alt attributes on images
- Correct use of ARIA labels and semantic HTML
- Keyboard navigability
Learn more about Lighthouse™ Accessibility scoring.
Best Practices
The Best Practices score checks whether your page follows modern web development standards, including:
- Use of HTTPS
- Absence of browser console errors
- Use of modern, secure APIs
- Correct image aspect ratios and resolutions
Learn more about Lighthouse™ Best Practices audits.
SEO
The SEO score checks whether your page is optimized for search engine discovery, including:
- Presence of a <meta> description and <title> tag
- Correct use of robots.txt and canonical tags
- Text legibility (font size, tap target spacing)
- Mobile-friendliness
Learn more about Lighthouse™ SEO audits.
How scores are color-coded
All four scores follow the Lighthouse™ (v.13.3.0) color scale:
- 🟢 score 90⁃100 : Good
- 🟠 score 50 ⁃ 89 : Needs improvement
- 🔴 score 0 ⁃ 49 : Poor
What are audits?
Each score is broken down into individual audits – specific checks run against your page.
Audit status
An audit can have one of three statuses:
- ✅ Passed – the page meets this best practice
- ❌ Failed – the page does not meet this best practice; action is needed
-
To improve – the score could be improved with recommended action(s)
Estimated metric savings
Audits show an estimated metric saving – a projected improvement on a specific Core Web Vital by taking an action (e.g., "fixing this could reduce LCP by ~240ms").
Use these estimates to prioritize which issues to address first.
Third-party audits
The audit list identifies third-party resources like scripts, fonts, analytics tools, and shows their contribution to your page load time.
Use this to assess the performance cost of each third-party vendor at a glance.
Tips: How to prioritize performance fixes
A report can surface dozens of audits across four categories. Here's how to cut through the list and focus on what matters most.
Step 1. Start with the score banner
The ‘Performance score’ banner at the top of the report tells you immediately whether your page is in a good, needs-improvement, or poor state. A red or orange Performance score means there are high-impact issues to fix before looking at other categories.
If the Performance score is already green, move to Accessibility, Best Practices, or SEO based on your team's current priorities.
Step 2. Filter audits by Core Web Vitals
In the ‘Analyze performance issues’ section, use the filter by option to narrow the list to a single Core Web Vital (for example, LCP if your page is slow to load, or TBT if it feels unresponsive).
You can additionally filter the list by 'Failling' or 'Improve'.
This instantly removes noise and shows you only the audits you should focus on improving.
Step 3. Prioritize audits by estimated metric saving
Within the filtered list, audits display an estimated metric saving (the projected improvement on that Core Web Vital if the issue is resolved).
Focus on the audits with the highest estimated savings first: these are the fixes that will move the needle most.
Where to start if you're not sure?
A slow LCP is the most common issue and the one with the greatest impact on user experience and search rankings. Filter audits by LCP, sort by estimated metric saving, and start there.