Improving your site server’s Time to First Byte (TTFB) is key to fast a performant site. A slow TTFB will cause site users to experience a blank screen whilst the site then loads.
Expected server TTFB times would be between 200 and 500 milliseconds. Some of the reasons why the TTFB could be over 500 milliseconds can be down to a high load on the site server, server infrastructure issues, and high latencies between DNS servers.
TTFB slower than 1 second or even higher should be a cause of concern and worth looking into what is causing such a high TTFB on your WordPress site.
Optimize the TLS handshake since slow TLS handshakes will cause slow site load issues and will contribute to slow TTFB on your site. If your site is using Lets Encrypt for the site’s SSL certificate it will not contribute to having a slower SSL chain.
The best way to test TTFB of a website is to check a static HTML file and then run through it on popular website performance testing tools like GTmetrix or WebPageTest.
If you have not deleted the default readme.html file on your WordPress install you can use that static HTML file as a site’s URL to test.
To find the TTFB when testing your site in GTmetrix, you will need to look in the Performance tab of the results then scroll down to the browser timings section.
Improving the TTFB of a website will definitely contribute to a faster website loading experience for website visitors.