What is PLS by on-page errors
PLS by on-page errors compares Perceived Load Speed (PLS) across pageviews that experienced different types of client-side errors — including JavaScript errors, image load failures, missing fonts, or broken CSS. It helps you understand how visual glitches or execution issues impact how fast the page feels to load.
PLS (Perceived Load Speed) is Uxify’s real-user metric that reflects the moment the page looks visually complete to users, based on all visible and meaningful content.
Even small client-side issues can delay the visual readiness of a page. A missing image, blocked font, or broken script may stall the appearance of key content, shift layout positions, or degrade the initial visual experience. These effects slow perceived load even if the technical load completes quickly.
Healthy PLS by on-page errors sample
Should you worry
In a healthy PLS by on-page errors view, the majority of pageviews show no errors and have good perceived load times. When errors do occur, they have minimal impact on user-perceived speed — staying in the green zone.
Yes, if pageviews with errors show significantly worse PLS than error-free ones. This may point to brittle frontend code, unstable assets, or poor third-party script handling. These delays often go unnoticed in lab tools, but your real users feel them — and act on them.
Unhealthy PLS by on-page errors sample
A high volume of slow pageviews correlating with on-page errors is a clear signal. Even minor issues like failed image loads or late script execution can disrupt the visual flow and increase the time users wait before engaging.
Resolving unhealthy PLS by on-page errors
Go-to action plan to resolve an unhealthy PLS by on-page errors:
Ask Uxi to analyze your PLS by on-page errors and suggest improvements.
Use Filters to identify which page types or device/browser combinations are triggering errors.
Simulate LCP of the suspected lens to see if fixing it will resolve the PLS by on-page errors. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your PLS by on-page errors.
Once you’ve improved PLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
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