What is TTFB by color depth
TTFB by color depth shows the Time to First Byte (TTFB) across users segmented by their screen’s color depth.
At first glance, this might feel like an odd pairing — but it’s actually a subtle way to surface device-class-based backend slowness. Lower color depth often correlates with slower CPUs, older operating systems, or atypical browsing environments — all of which can delay request initiation or affect client networking.
💡 TTFB is a measure of how fast the first byte of your page is received after navigation. It captures DNS, connection setup, and server processing time.
Healthy TTFB by color depth sample
Should you worry
In a healthy case, TTFB remains green across all variations of color depth. That’s what you want — because network and server-side response should be largely device-agnostic.
Unhealthy TTFB by color depth sample
What to look for:
Higher TTFB on 16-bit clients may indicate:
Long DNS resolution times (often seen on enterprise or restricted networks).
Slow TLS negotiation due to outdated client stacks.
Cold starts caused by underused endpoints (possibly test bots or legacy clients).
Weird color depths with high TTFB often point to automated testing tools or emulated environments.
Enterprise traffic spikes might bring in legacy machines or browser setups that delay requests.
While not always user-impacting, it’s smart to watch these cases if they also show high bounce or session drop rates.
Resolving unhealthy TTFB by color depth
Go-to action plan to resolve an unhealthy TTFB by color depth:
Ask Uxi to analyze your TTFB by color depth values and suggest improvements.
Filter by given color depth 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 color depth. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by color depth 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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