Synthetic jobs will automatically take screenshots for you, but you might want to manually take screenshots to debug issues.
Where to Find Screenshots
The Session Details dialog shown below displays screenshots for each page, the last screenshot taken in the session, and a screenshot icon in the waterfall showing when the screenshot was taken. You can also view the larger version of the page screenshot from the Screenshots tab.
When to Use Screenshots to Debug
If interactions with a page are resulting in failures, you can use a screenshot to detect whether the UI component is on the page. For example, a screenshot can be used to determine if you are trying to click a button that isn't on the page or that is being overlapped by another HTML component. You may also want to manually take a screenshot if your job is timing out to diagnose an issue with the page because screenshots are not be automatically taken for timed out jobs.
How to Take Manual Screenshots
Although screenshots are taken by default, you can manually take screenshots at any point during the execution of your script using either of the following: