What is PLS by FCP
PLS by FCP helps you understand how First Contentful Paint (FCP) relates to Perceived Load Speed (PLS). It shows whether a fast FCP (when the first visual element appears) actually results in a fast, perceived load for the user — or whether something later slows things down.
PLS is Uxify’s real-user performance metric that reflects the moment users feel the page is visually ready. FCP is a browser-native metric that marks when any content (like text or image) is first rendered. But just because something appears doesn’t mean the user thinks the page is ready.
FCP marks the very first visual change — often just a background, loader, or navbar. But users care more about when the full content they came for becomes visible.
By comparing PLS to FCP, you can:
Identify misleadingly “fast” pages (with quick FCP but slow PLS)
Detect content shifts, lazy-loaded elements, or layout delays after FCP
Uncover rendering bottlenecks that occur after initial paint
Healthy PLS by FCP sample
Should you worry
A healthy trend shows low PLS values on pages with fast FCP. That means the initial paint leads naturally to full content loading — so users feel like the page loaded quickly.
If FCP is fast but PLS is slow, users are seeing something — but not what they expect. That disconnect creates perceived slowness, even if technical metrics look fine.
This can happen when loaders, skeletons, or layout shifts delay full rendering. Users notice when visual progress stalls after the first paint.
Unhealthy PLS by FCP sample
A common pattern in unhealthy cases: FCP is under 1s, but PLS exceeds 2s. This suggests the page starts quickly, but full content — like banners, product grids, or hero images — takes longer to appear.
That gap between “something showed up” and “the page feels ready” breaks the illusion of speed.
Resolving unhealthy PLS by FCP
Go-to action plan to resolve an unhealthy PLS by FCP:
Ask Uxi to analyze your PLS by FCP and suggest improvements.
Use Filters to isolate these pages and explore contributing lenses (device, CPU, third-party).
Simulate LCP of the suspected lens to see if fixing it will resolve the PLS by FCP. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your PLS by FCP.
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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