First Byte Time (back-end processing): NA

Web Performance Discuss Test Results
1

What does this mean? I normally get a letter but for some of my pages I am getting

First Byte Time (back-end processing): NA

I googled it an came up with nothing.

2

Do you have an example test? N/A just means that WebPagetest didn’t think it could calculate a grade but I’d like to see why.

3

Hi thanks for you for your reply. I have tested this same page numerous times and keep getting the same result.

Here is the test http://www.webpagetest.org/result/150115_2R_T6C/

the page being testing is Order Driving Records Nationwide - Instant Results

4

Looks like it’s an issue with Chrome SSL testing (specifically Chrome’s reporting of the timings) where the beginning of the test gets clipped so I don’t have a TTFB. It’s caused by some internal races in Chrome and dev tools doesn’t record accurate times in this case. It’s on my list to see if I can either fix in Chrome or find a better way to capture the data (likely the latter).