Waterfall summary

The Waterfall summary page shows you the critical measurements for each step of a single test execution.

Drill down to the Waterfall summary page through the analysis workflows for these pages:

In the Waterfall summary page, data is available for all test executions within the same hour as the selected execution, even if the parent chart's time frame is longer than 1 hour. For example, from a test that ran at 11:40, you can go back or forward to other test executions (if any) between 11:00 and 12:00.

The Waterfall summary page provides the following information:

  1. The test name and measurement location.
  2. The date and time of the selected test execution.
    Click the previous or next icon to go to other test executions within the same hour. Click the timestamp for the Selected execution to see a list of all available test executions; click a timestamp in the list to go to that test execution. The value in parentheses after a timestamp is the UX time for the test execution. This value will be zero when Include client (non-network) time in results is disabled in the test settings.
  3. If the test failed, a brief description of the error that caused the failure is displayed below the timestamp.
  4. Summary statistics:
    • Total steps
    • Visually complete
    • Network time
    • UX time
    • Bytes downloaded
  5. If errors or performance problems occurred, a summary of the problem analysis.
  6. The number of steps completed. This number may be less than the Total steps if the test failed.
  7. Network time, interactive time, and UX time for the step.
  8. A timeline that graphically depicts the metrics collected for the step, using a different color for each metric.
    If the timeline is not displayed, click the the expand icon at the end of the step to display it.
    Hover over a color section of the timeline to view the metric and its value.

Waterfall summary metrics

  • Bytes downloaded – Total number of bytes for all the objects downloaded in all steps.
  • Interactive time – The time it takes for the page to load to the point the user can interact with the page. This metric corresponds to the W3C metric load event end.
  • Network time – The total time of all network traffic for a page, from the base page's DNS lookup through delivery of the last packet of the last resource.
  • UX time – Perceived load time of the page. This is the time it takes for the page to appear loaded to the user although the browser may still be downloading items in the background. UX time may be equal to or higher than network time if it includes times when there is no network activity, as when the system is processing resources.
  • Visually complete – The total time to render all the content in the browser's visible area, i.e. all the web page content that's visible without scrolling; content "below the fold" and non-visible content does not affect the metric. This metric is only available for Backbone tests that run on the Chrome 56 Agent.

Drilldowns for data analysis

From the Waterfall summary page, you can drill down to the Waterfall chart or the Problem analysis page. You can also view screen captures if Screen Capture on Error is enabled for the test and errors occurred.

Analyze in waterfall

Click a step name or click Analyze in waterfall below the step's timeline to drill down to the waterfall chart. The waterfall shows metrics for every object downloaded in the step. For details, see Waterfall chart.

Drill down to problem analysis

If errors or performance problems occurred, the Waterfall summary page includes an Analysis section that identifies the page (step) where the issues occurred, and provides summary information for the issues that contributed to the overall problem. Click Analyze problems to go to the Problem analysis page. For more information, see Problem analysis.

View screen captures

If an error occurred in the test execution and screen captures are enabled for the test, a thumbnail of the first screen captured in the step is displayed at the end of the timeline for each step. Click the thumbnail to view a larger image in a popup window.

To go to the Screen capture page to see more information for the screen captures, click View screen capture at the top of the Waterfall summary page. This button only appears when screen captures are available.