TTFB (Time to First Byte)
The time elapsed from request to receiving the first byte of the page response from the server.
What is TTFB?
Time to First Byte (TTFB) measures the duration from when a user's browser sends an HTTP request to when it receives the first byte of the response from the server. TTFB encompasses DNS lookup, TCP connection, TLS negotiation, and server processing time. While not officially a Core Web Vital, TTFB is a critical diagnostic metric because it sets the baseline for all other loading metrics — you cannot have a fast LCP if your TTFB is slow.
Google recommends a TTFB under 800ms. For optimal performance, aim for under 200-400ms. TTFB varies significantly based on the user's geographic distance from the server, the server's processing time, and network conditions.
Why It Matters for Publishers
TTFB is the starting gun for page loading. Every millisecond of TTFB delay pushes back LCP, INP, and the time until ads can begin loading. A publisher with a 2-second TTFB is starting the race 2 seconds behind a publisher with a 200ms TTFB, making it nearly impossible to achieve competitive LCP scores.
For publishers, TTFB issues often stem from slow shared hosting, unoptimized CMS databases (especially WordPress with excessive plugins), lack of caching, or serving users from geographically distant servers. Addressing these foundational issues has a cascading positive effect on all performance metrics.
Tips for Optimization
- Use a CDN: A Content Delivery Network serves content from edge servers geographically close to users, dramatically reducing TTFB for visitors far from your origin server.
- Implement full-page caching: Cache rendered HTML pages so the server doesn't need to rebuild them for every request. WordPress sites should use caching plugins like WP Super Cache or W3 Total Cache.
- Upgrade hosting: Shared hosting often produces TTFB of 1-3 seconds. Upgrading to a managed WordPress host or VPS can reduce TTFB to 200-500ms immediately.
- Optimize database queries: Slow database queries are a common cause of high TTFB in CMS-powered sites. Audit and optimize your most frequently run queries.
- Reduce redirect chains: Each redirect adds a full round-trip to your TTFB. Minimize redirects and ensure www/non-www and HTTP/HTTPS redirects are handled efficiently.