What is PLS by HTTP status code
PLS by HTTP status code breaks down your Perceived Load Speed (PLS) based on the HTTP status returned by the server for each pageview. This helps you understand how different response statuses — such as 200 OK, 301 Redirect, 404 Not Found, or 500 Server Error — affect how fast users perceive your pages to load.
Since server response behavior can significantly influence load time, this lens is particularly useful when tracking down invisible bottlenecks or backend misconfigurations.
Healthy PLS by HTTP status code sample
Should you worry
In a healthy case, most pageviews return 200 OK with fast perceived load speeds. Small amounts of redirects (301, 302) are expected, and ideally, they don’t drag down PLS significantly. However, large volumes of redirects or unexpected status codes like 404s and 500s can degrade performance and introduce delay in rendering.
If you notice slow PLS associated with non-200 status codes, it's time to dig into what’s happening server-side.
Unhealthy PLS by HTTP status code sample
Poor perceived load speed correlated with status codes like 301, 404, or 500 can point to:
Redirect chains that delay visual load
Pages linking to non-existent URLs
Backend instability or misconfigured APIs
While these errors might not always show up in frontend metrics, they can cause real frustration for users if the page appears broken, incomplete, or slow to finish loading.
Resolving unhealthy PLS by HTTP status code
Go-to action plan to resolve an unhealthy PLS by HTTP status code:
Ask Uxi to analyze your PLS by HTTP status code and suggest improvements.
Filter by high PLS sessions with unexpected codes (e.g., 301, 404, 500), then inspect trends by URL, browser, or referrer.
Simulate LCP of the suspected lens to see if fixing it will resolve the PLS by HTTP status code. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your PLS by HTTP status code.
Once you’ve improved PLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
Discover how your website performs with real user data.