Before a browser can show anything, the server has to answer. Time to First Byte measures that wait: DNS lookup, connecting, any redirects, and the time the server spends building the page, up to the moment the first piece of the response arrives.
TTFB isn’t one of the Core Web Vitals, but it sits underneath all of them. Every millisecond of TTFB is a millisecond added to Largest Contentful Paint. Google’s web.dev guidance suggests aiming for 0.8 seconds or less at the 75th percentile of real visits.
Why it matters
Coastline Plumbing’s WordPress site runs on cheap shared hosting with no page caching. Every visit makes WordPress run dozens of database queries to build the page from scratch, and the server is in another country. TTFB sits around 1.8 seconds. That means the page can’t pass the 2.5-second LCP target on most phones, no matter how well the images are optimized.
Slow responses also affect crawling. When a server responds slowly, Googlebot reduces how much it crawls to avoid overloading it, which matters on larger sites with a tight crawl budget.
What makes TTFB slow
- No page caching, so every request is built from scratch
- Underpowered or overloaded hosting
- Heavy plugins running slow database queries on every page
- Visitors far from the server with no CDN
- Redirect chains, since each hop adds a full round trip before the real response
How to reduce it
- Turn on full-page caching. On WordPress, many hosts provide it, or plugins like WP Rocket, LiteSpeed Cache or W3 Total Cache can.
- Use a CDN that caches HTML, not just images, so pages are served from a location near the visitor.
- Upgrade hosting if the server is consistently slow even with caching.
- Find and replace slow plugins. Query Monitor shows which ones run the most database queries.
- Link straight to final URLs so visitors don’t pass through redirects.
How to check
curl -o /dev/null -s -w "TTFB: %{time_starttransfer}s\n" https://www.example.com/Run it a few times, since the first request may miss the cache. PageSpeed Insights reports field TTFB from real Chrome users, which is the more reliable number. Search Console’s Crawl Stats report shows the average response time Googlebot sees. RankThat’s Site Audit includes server response time in its speed checks.
Common mistake
Testing only from your office, close to the server, with a warm cache. Real visitors arrive from everywhere on mobile networks, and many hit uncached pages.