What is TTFB by third party
TTFB by third party shows how different external services impact Time to First Byte (TTFB) — the time it takes for your server to start responding to a request.
This lens helps you catch cases where third-party integrations (e.g., redirects, authentication, personalization APIs, or server-side tags) are slowing down the backend response.
Only third-party sources that were active and measurable during the selected period are shown.
Why it matters: TTFB is the first impression of speed. If a third party delays server response — even before your content starts loading — the entire page can feel sluggish.
Healthy TTFB by third party sample
Should you worry
In a healthy TTFB by third party view, external services either have no impact or run in parallel without blocking the server response.
This often reflects:
No synchronous third-party calls in the request chain.
Server-side logic is lean and independent.
Proper caching of third-party responses or fallbacks when slow.
If your TTFB remains fast regardless of integrations, you’re well-positioned.
Unhealthy TTFB by third party sample
If certain third parties appear consistently with high TTFB impact, it usually indicates:
Blocking requests to personalization or consent APIs.
Synchronous server calls to marketing or analytics tools.
Dependencies that slow down dynamic rendering.
Top offenders include:
Identity verification tools.
Personalization or geo-targeting scripts.
Server-side A/B testing frameworks.
In these cases, even users with fast internet may wait a long time before your page even begins loading.
Resolving unhealthy TTFB by third party
Go-to action plan to resolve an unhealthy TTFB by third party:
Ask Uxi to analyze your TTFB by third party values and suggest improvements.
Use Filters to isolate affected pages, user types, or routes.
Simulate TTFB of the suspected lens to see if fixing it will resolve the TTFB by third party. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by third party 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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