What is TTFB by browser timezone
TTFB by browser timezone shows the Time to First Byte (TTFB) segmented by the timezone of the user’s browser. This lens is a powerful diagnostic for identifying backend or network slowness across regions — without needing precise location data.
Only timezones with active traffic during your selected range are displayed.
🕒 Timezone is based on the user's local system clock, not IP. This keeps the data lightweight and privacy-friendly, but still useful for understanding geographic TTFB variation.
Why it matters: TTFB reflects how quickly your server or CDN starts delivering the page. When TTFB varies heavily by timezone, it typically means you’re facing issues with:
Poor CDN placement.
Slow origin fetches.
Server location mismatches.
Healthy TTFB by browser timezone sample
Should you worry
In a healthy view, all browser timezones are green or light yellow. Minor delays can be expected in under-provisioned regions or during peak load, but nothing should hit red unless something's misconfigured.
This usually indicates:
Your CDN edges are doing their job.
Origin latency is under control.
You’re not overloading any specific region with backend logic.
Unhealthy TTFB by browser timezone sample
If certain timezones show consistently slow TTFB:
You may have missing edge nodes or underused CDN resources in that region.
Origin requests might be traveling too far due to bad routing.
There may be region-specific backend logic (e.g. translations, price localization) delaying response.
Backend errors or overloads could be causing slow cold starts.
These slowdowns hit users hardest in first-page loads and non-cached paths — often before INP or LCP even get a chance to play out.
Resolving unhealthy TTFB by browser timezone
Go-to action plan to resolve an unhealthy TTFB by browser timezone:
Ask Uxi to analyze your TTFB by browser timezone values and suggest improvements.
Filter by given timezone and look at other lenses to pinpoint the culprit.
Simulate TTFB of the suspected lens to see if fixing it will resolve the TTFB by browser timezone. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by browser timezone values.
Once you’ve improved TTFB, 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.