WordPress speed optimization · SaaS

How we cut a SaaS marketing site's LCP from 4.8s to 1.6s without a rebuild

A SaaS marketing site was failing Core Web Vitals on mobile. The hero loaded a 1.4 MB unoptimised PNG above the fold and the theme blocked rendering with 9 synchronous scripts. We cut LCP from 4.8s to 1.6s in two weeks with no rebuild. Full recorded evidence is available on request during a discovery call.

4.8s to 1.6s
Mobile LCP
67%
Faster perceived load
0
Theme rebuild needed

The challenge

The hero image was a 1.4 MB PNG served at full desktop size on mobile. Nine scripts ran synchronously in the head. Critical CSS was inline but covered the entire stylesheet, not just above the fold. CWV was failing on mobile.

What we did

  1. 1

    Converted the hero to a properly sized AVIF with a fallback, preloaded for mobile.

  2. 2

    Moved 7 of 9 scripts to defer or async, removed 2 that were unused.

  3. 3

    Generated a real above the fold critical CSS file, deferred the rest.

  4. 4

    Added font preconnect and font display swap to stop the FOIT flash.

The result

Mobile LCP dropped from 4.8s to 1.6s. The page passed Core Web Vitals on the next CrUX update. No theme rebuild, no design change. The client kept the same designer and the same brand look.

We thought we needed a rebuild. They proved we did not. Client identity withheld under NDA. Full Loom recording and dated evidence are available on request during a 15 minute discovery call.
Head of growth · B2B SaaS company (identity withheld under NDA)

Common questions

Do you always need a rebuild to pass CWV?

Almost never. Most CWV failures are fixable inside the existing theme by handling images, fonts, and script loading correctly.

Want a recovery like this?

Evidence on request

Every fix is recorded. Every outcome is verifiable.

We have 500 plus recorded engineer sessions covering migrations, malware cleanups, speed wins, and emergency recoveries. Most clients are under NDA, so we cannot publish them publicly. On a 20 minute discovery call we will show you the recordings, dashboards, and before and after numbers most relevant to your situation.

  • Loom walkthroughs of real client recoveries, narrated by the engineer who did the work.
  • Anonymised case files with PageSpeed, GSC, and uptime evidence, NDA respected.
  • References from named clients available on the call when there is a fit.

On your discovery call you will see

500+

Recorded fixes

150+

Sites managed

100%

Confidential

Book a 20 minute call

No pitch. We will show evidence relevant to your site.

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