Digital Marketing
Website Speed & Conversions: The Simple Wins That Move Revenue
By Dominik Kowalski · Updated 21 Aug 2025 · 10–14 min read
Purpose: Turn faster rendering and lower interaction latency into measurable conversion gains—especially for Australian users on mobile.
TL;DR: Fix what impacts LCP (hero image, render‑blocking CSS/JS) and INP (heavy JavaScript, third‑party scripts) for AU users first. Aim for LCP < 2.5s, INP < 200ms, CLS < 0.1, and AU TTFB < 800ms (preferably < 500ms). Measure with field data (CrUX) and annotate changes in analytics.
Why speed moves conversions
Speed reduces abandonment and increases the number of people who reach and complete your key journeys. Whether you collect leads or run ecommerce, shaving seconds off the first meaningful paint and keeping interactions snappy is one of the highest‑ROI changes you can make.
- LCP: Faster hero/product render increases scroll depth and CTA views.
- INP: Snappy taps and forms reduce drop‑off post‑click.
- CLS: Stable layouts keep users focused on the task.
References: web.dev, Chrome UX Report (CrUX).
AU field-data targets (practical)
| Metric | Good | Okay | Action |
|---|---|---|---|
| LCP | < 2.5s | 2.5–4.0s | Optimise hero image, reduce render‑blocking, inline critical CSS |
| INP | < 200ms | 200–500ms | Cut JS, defer non‑critical, reduce third‑parties |
| CLS | < 0.1 | 0.1–0.25 | Set image/video dimensions, reserve space for embeds |
| TTFB | < 500ms | 500–800ms | Cache pages, move origin to AU, enable HTTP/3 |
If most of your audience is in AU, consider an AU origin for dynamic pages. See our guide: AU hosting & SEO.
Quick wins you can ship today (30–90 minutes)
- Convert hero images to AVIF/WebP and serve responsive sizes (srcset). Compress to ~60–80% visual quality.
- Lazy‑load all below‑the‑fold images/iframes. Avoid lazy‑loading the hero.
- Defer non‑critical JS and remove unused libraries. Inline only tiny, critical scripts.
- Preconnect to critical third‑party origins (fonts, CDN) and use
rel=preloadfor the hero image. - Cache pages for anonymous traffic and serve via CDN POPs in AU.
Then retest with PageSpeed Insights and WebPageTest (Sydney). Track field improvements over the next few days.
One-day implementation plan
- Image strategy: AVIF/WebP, responsive sizes, lossless logos, remove oversized assets.
- CSS: Extract critical CSS for above‑the‑fold, defer the rest, remove unused styles (purge).
- JS: Split bundles, defer analytics until user interaction where acceptable, cap total JS.
- Caching: Public cache for HTML where safe; strong caching for static assets; validate vary headers.
- Network: HTTP/3, TLS 1.3, Anycast DNS; minimise redirects and resolve long chains.
Related reading: Top hosting mistakes that kill performance and Shared vs VPS vs Cloud.
Proving impact (analytics + RUM)
- Annotate changes in analytics (date/time, pages affected).
- Segment AU mobile traffic and track conversion rate, bounce, and time to first action.
- Ingest Core Web Vitals into analytics or use a RUM library; monitor LCP/INP/CLS distributions.
- Compare before/after windows, controlling for seasonality and promo periods.
Tip: If you can, A/B test heavy vs. optimised variants on high‑traffic templates.
Pragmatic support: If you need help prioritising where performance meets ROI, the team at Dominik Digital Marketing provides technical SEO and CRO guidance. Start with a performance assessment or visit the site directly: https://domdigitalmarketing.com.au/.