Introduction to reports
A report is generated every time you run a web performance test in Synthetic Monitoring. It gives you a detailed view of how a page performed at the time of the test, from Core Web Vitals, other performance metrics, audit scores to video replay, waterfall, as well as detailed audit.
Use reports to understand what is slowing your pages down, prioritize the fixes with the highest impact on your Core Web Vitals, and track standardized scores over time.
There are two types of reports
Standalone reports: a full performance analysis of a single page (see How to run a web performance test in Synthetic Monitoring)
Comparison reports: a side-by-side view of two or more pages, including competitor pages (see How to create a web performance Comparison Report)
Access your Synthetic Monitoring Reports
- any web performance test you run (the report is available immediately after you execute the test)
- your Synthetic Monitoring Dashboard and Reports tabs
- any comparison report
- any graph in any Monitoring
Reports are rendered in either English or French, consistent with the language specified in your profile.
Manage your reports
Click to open one of the reports.
From the top left, you'll see the URL of the tested web page and the analysis context of the test.
- Click on the ‘...’ menu to access configuration.
- Select ‘Retest’ to launch a new test with the same configuration.
- Use the 'Monitor this page' button to create a new Monitoring.
- Click the Download icon to export the full report as a PDF
Performance indicators
Performance score banner
The Performance score banner appears at the top of the report and gives you an immediate read on your page's performance.
- The ‘Performance score’ is a weighted average of five Core Web Vitals: LCP, TBT, CLS, FCP, and Speed Index, measured under simulated load conditions.
- Jump directly to the Performance issues section so you can start investigating without scrolling, by clicking on the ‘View performance issues’ button.
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.
Performance metrics
This section gives you a full picture of your page's performance in one place. Metrics are interactive and clicking them takes you to the relevant section of the report or opens an additional view.
Core Web Vitals
Three Core Web Vitals are displayed with color coding:
| Metric | What it measures | Clicking it… |
|---|---|---|
| LCP (Largest Contentful Paint) | When the largest visible content element finishes loading | Scrolls to the video replay at the LCP moment and filters the Performance audits to LCP |
| TBT (Total Blocking Time) | How long the main thread is blocked by long tasks, delaying interactivity | |
| CLS (Cumulative Layout Shift) | How much the layout unexpectedly shifts | Scrolls down and filters the Performance audits to CLS |
Note that Contentsquare uses TBT as its interactivity metric as it remains a reliable lab metric to diagnose and improve interactivity performance.
Secondary metrics
Click ‘See more metrics’ to expand the secondary metrics panel.
| Metric | What it measures | Clicking it… |
|---|---|---|
| FCP (First Contentful Paint) | the time until the browser renders the first piece of visible content | Filters the Performance audits to FCP |
| Speed Index | How quickly the visible content of the page is populated during loading | Opens the Filmstrip |
| First Byte (Time to First Byte) | The time between the browser sending a request to the server and receiving the first byte of the response | Opens the Waterfall |
| Start Render | The moment the browser first paints anything visible on screen. | Scrolls to the video replay at the Start Render moment |
| Visually Complete | When all visible content in the viewport has finished rendering. | Scrolls to the video replay at the Visually Complete moment |
| Weight | Shows the total page weight split by resource type (HTML, CSS, JS, images, and others). | |
Video replay
This section displays the web performance metrics calculated from the video analysis of your page loading. Use it to see how the page loads and how users experience it.
- Click the metric name (Start Render, FCP, LCP, or Visually Complete) to jump to that point in the video.
- Clicking on LCP will additionally highlight the largest visible content element in the replay.
LCP event information
When you select LCP, the following details appear:
- Element: ID, class, or filename of the LCP element
- Size: Ratio computed relative to the viewport, based on the element's width and height
- HTML code: An extract of the HTML code to help you identify the LCP element
- Weight: Size of the image file (shown only if LCP is triggered by an image)
-
Path: Full path of the request triggering the LCP (shown only if LCP is triggered by an image)
Filmstrip
Click ‘Show filmstrip’ to view your page loading frame by frame at regular intervals.
Each frame displays the rate of rendering completion relative to the final state.
The 'Visually Complete' timestamp marks the point at which the visible content has finished rendering from the user's perspective, which typically corresponds to a rendering rate at or near 100%.
Waterfall
By clicking the ‘Network’ button, you access the waterfall lists all network requests (HTTP, etc.) required to load the page, including assets like images, JavaScript, and web service calls.
- The Timings section lists the values of all performance metrics for the page.
- The Long Tasks section shows where the browser is busy for more than 50ms and the Total Blocking Time.
- The Waterfall section displays the sequential list of all HTTP requests.
Waterfall AI Summary
Use the ✦ button to display an AI-based summary that translates complex network data into plain-language insights, issues and recommendations.
Analyze performance issues
This section lists all audits run on your page, grouped by the four categories, and gives you insights on how to act on them: Performance, Accessibility, Best Practices, and SEO, each measuring a distinct quality dimension of your web page.
Audit scores
| Score | What it measures |
|---|---|
| Performance | How fast and smooth the page loads for users, based on LCP, TBT, CLS, FCP, and Speed Index |
| Accessibility | How easy the page is to use for people with disabilities, following WCAG guidelines |
| Best Practices | Whether the page follows modern web development standards |
| SEO | How well the page is optimized for search engine discovery |
Each score is color-coded following the applicable threshold.
Each audit shows:
- A pass / fail / informational status indicator
- A description of the issue and guidance on how to fix it
- An estimated metric saving (where applicable): the projected impact on a Core Web Vitals (LCP, TBT, CLS, etc.) if the recommendation is applied.
See Understanding Lighthouse™ (v.13.3.0) Scores in Performance Audit Reportsfor a step-by-step approach.
Filter your audits
Use the ‘filter by’ option to focus on audits that impact a specific Core Web Vital.
You can also filter by the most critical issues, by selecting ‘Failing’ or ‘To improve’.
This helps you prioritize fixes with the highest impact on user experience.