What is TTFB by device memory
TTFB by device memory shows the Time to First Byte (TTFB) value across different levels of user device memory (e.g. 2GB, 4GB, 8GB). This lens helps you understand how the device’s memory capacity affects the time it takes to receive the first byte of a page from the server.
Only device memory configurations that generated traffic during the selected period will be listed.
While TTFB is mostly a server-side metric, weaker devices with lower memory can delay request execution or increase DNS/connection times — especially in edge cases or poor network environments.
Healthy TTFB by device memory sample
Should you worry
A healthy TTFB by device memory lens is all green. That means your site’s server or CDN responds fast, regardless of how powerful or limited the user’s device is.
Unhealthy TTFB by device memory sample
In this example, devices with 2GB or less memory show noticeably slower TTFB. This suggests performance bottlenecks are affecting users on entry-level or older hardware — possibly due to initial connection delays or unoptimized backend logic that performs poorly under constrained conditions.
Resolving unhealthy TTFB by device memory
Go-to action plan to resolve an unhealthy TTFB by device memory:
Ask Uxi to analyze your TTFB by device memory values and suggest improvements.
Use Filters to isolate the struggling memory segment. Then pivot to TTFB by country or TTFB by page to identify deeper patterns (e.g. geographic latency or heavy pages).
Simulate TTFB of the suspected lens to see if fixing it will resolve the TTFB by device memory. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your TTFB by device memory 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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