What is TTFB by page zoom
TTFB by page zoom shows how Time to First Byte (TTFB) varies based on the browser’s zoom level during a page visit. While TTFB is primarily a server-side metric, zoom-related client conditions can sometimes create indirect effects — especially with client-side redirects or conditional logic.
Healthy TTFB by page zoom sample
Should you worry
In a healthy TTFB by page zoom lens:
TTFB values stay consistent regardless of zoom level
Zooming in or out doesn’t delay the server’s initial response
No signs of unnecessary re-navigation or layout-based fetching
This means your infrastructure is robust and zoom states aren’t triggering unexpected overhead.
Unhealthy TTFB by page zoom sample
If zoomed users have slower TTFB, possible causes include:
Client-side scripts triggering re-navigation or localization logic based on layout width
Conditional logic tied to viewport dimensions that indirectly delays request timing
Edge personalization logic that adapts content based on detected zoom-in page metrics
Although rare, zoom-induced layout changes can sometimes affect client behavior that impacts how quickly the request even starts.
Resolving unhealthy TTFB by page zoom
Go-to action plan to resolve an unhealthy TTFB by page zoom:
Ask Uxi to analyze your TTFB by page zoom values and suggest improvements.
Use Filters to focus on the zoom level with degraded TTFB.
Simulate TTFB of the suspected lens to see if fixing it will resolve the TTFB by page zoom. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by page zoom values.
Once you’ve improved TTFB, set an alert to be the first to know if it starts worsening again.
Try it yourself
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