Introduction
Leverage the advanced Speed Analysis Lab settings to test a page with and without the service or resource and compare the results, to measure its impact on different metrics
Use case examples:
- I want to test the impact of a specific 3rd party resource
- I want to understand if a specific tag is impacting the experience of my users
- I want to ignore a resource that may tamper with the overall loading time of my web page
- I want to block consent manager to understand the impact
Set up the analysis
First you will need to test with a manual analysis to make sure one report is set up with the resource blocked and the other report without the blocked resource.
Set up the first report
1. Go to the Analyze tab
2. Enter the page URL
3. Select Blocklist from the settings tab
4. Enter the details of the resource to block and then select Analyze my page
5. Open the timeline in waterfall to make sure the resource is not loaded
Tip: Update the report name to make it easier to search for in the Reports dashboard. E.g. Homepage - With Blocking |
Set up the second report
1. Go to the Analyze tab
2. Enter the page URL
3. Select Analyze my page
Tip: Update the report name. E.g. Homepage Without Blocking |
Compare the results
1. Go to the reports menu and use the dashboard to see an overview of the core web vitals to see how the metrics are impacted with and without the resource.
2. Select the 2 reports using the checkboxes
3. Select Compare to view the comparison report to see the impact of the specific script on the page performance (often mainly Blocking Time).
Compare over time
We recommend creating monitors and compare them over time so you can ensure that the performance of one version is better than another. This is because web performance metrics are often volatile as they depend on a lot of factors.
1. Select the Monitoring tab and select Create a Group
2. Enter the name of your group
3. Select the pages to add to your group of monitors and select save.