The symptom
- PageSpeed Insights reports *Reduce initial server response time*; TTFB 1–3 seconds.
- Shared hosting, no object cache, 40+ active plugins, or WooCommerce cart fragments firing on every page.
Why it matters
Crawlers scale how much they fetch to how fast you answer; slow stores get fewer pages crawled and refreshed. Shoppers on mobile abandon after ~3 seconds. Core Web Vitals (LCP) is directly delayed by TTFB.
How to check it yourself
- PageSpeed Insights → Diagnostics → Initial server response time; or
curl -o /dev/null -s -w "%{time_starttransfer} " https://yourstore.com/. - Test a product page and a category page, not just the home page.
How to fix it
- Full-page cache for guests (LiteSpeed Cache, WP Rocket, FlyingPress or host-level cache) with WooCommerce exclusions for cart, checkout, my-account.
- Object cache (Redis/Memcached) — most managed hosts offer it; huge win for category pages and search.
- Disable *cart fragments* on non-shop pages; audit plugins with Query Monitor and remove the heavy ones.
- PHP 8.2+, HTTP/2 or HTTP/3, and a CDN (Cloudflare) in front. If the host cannot deliver TTFB < 500 ms with caching, move.