What is TTFB by visitor ID
TTFB by visitor ID lists anonymized visitor IDs and the Time to First Byte (TTFB) each experienced—color-coded to expose backend or routing delays that persist across visits for the same person.
Time to First Byte (TTFB) is the time from request start until the first byte of the response is received.
TTFB by visitor ID sample
Should you worry
Mostly green IDs show stable server responsiveness for both first and returning visits—even when authenticated or personalized.
Unhealthy TTFB by visitor ID sample
Yellow/red clusters point to recurring backend latency for certain IDs—often tied to region, authentication, cold starts, or heavy personalization queries.
Resolving unhealthy TTFB by visitor ID
Go-to action plan to resolve an unhealthy TTFB by visitor ID:
Ask Uxi to analyze your TTFB by visitor ID values and suggest improvements.
Use Filters to contrast first vs. repeat TTFB; confirm edge caching warms as expected.
Simulate TTFB of the suspected breakdown to see if fixing it will resolve the TTFB by visitor ID. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by visitor ID 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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