“How fast is fast enough?” is the first question every B2B marketing lead asks us, usually after a board member complains the site feels sluggish. We benchmarked 12 client B2B sites — SaaS, manufacturing, logistics, and distribution — and can now give numbers instead of opinions.
The numbers from production traffic
Across the 12 sites, median mobile LCP on landing pages was 1.9s; the best performer sat at 1.2s, the worst at 4.1s. The two slowest sites shared one trait: a heavyweight page builder layered on a heavy theme. After a cleanup pass (theme diet plus caching — the process in our slow-theme guide), the worst site dropped to 1.8s without a redesign.
The budget we set for B2B builds
- LCP under 2.0s on cached lead pages, mobile 4G.
- TTFB under 400ms uncached, under 200ms cached.
- Under 500 KB total page weight before hero images.
- Under 200 KB from theme assets specifically.
These are stricter than Google’s “good” thresholds on purpose: B2B landing pages carry tracking scripts and CRM embeds that eat budget after launch. Start lean or the tag manager will finish the job of slowing you down — see our Core Web Vitals guide for the measurement workflow.
What actually moves the needle
Ranked by impact across those 12 cleanups:
- Removing unused theme modules and demo assets (average 0.4s LCP improvement).
- Proper full-page caching with role-safe exclusions (0.3–0.6s; see the caching guide).
- Hero image discipline — WebP, sized to the slot (0.2–0.5s).
- Hosting upgrades — last, because it only helps once the page is light.
Why B2B speed matters beyond SEO
Sales demos run through your site on whatever network the meeting room has. Ad landing pages compete against three other vendors’ tabs. In our client data, lead pages that improved from ~3s to under 2s saw form completion rates rise 8–15% — the same pattern we measured in the B2B theme lead-gen test.
Want your own numbers before committing to work? The free WordPress site audit returns your LCP, TTFB, and the three biggest page-weight offenders, with the fixes ranked by effort.
Under 2.0 seconds on mobile for cached landing pages. Google's 'good' threshold is 2.5s, but B2B pages accumulate tracking scripts after launch, so build with margin. Yes. In our client data, lead pages that improved from ~3s to under 2s saw form completion rates rise 8–15% on similar traffic. Fix the theme first — it is cheaper and usually the bigger lever. Hosting upgrades help most once page weight is under control. Use field data from real users (Search Console CWV report) plus lab tests on your top three landing pages with WebPageTest on mobile 4G, both cached and uncached.What is a good LCP for a B2B website?
Does B2B site speed affect lead generation?
Should we upgrade hosting or fix the theme first?
How do I measure my B2B site's real speed?
