High-speed website design – Faster sites sell better

Why does website speed matter?

Research from Google and other reputable organisations shows that 53% of mobile users leave a site that takes more than 3 seconds to load. Every extra second cuts conversion by 7%. A slow website doesn't just lose customers — Google also penalises its search rankings.

In an age when people are used to the instant experience of TikTok, Instagram and modern apps, customers have almost zero patience for slow websites. They don't wait and they don't come back — they go to a competitor with a faster site. That's the harsh reality, but also a big opportunity: when your site is faster than your competitors', you keep the customers they lose.

Website speed isn't just a technical issue — it's a business issue. Every millisecond of delay can be measured in money: fewer customers, fewer orders, higher ad costs and lower Google rankings. Conversely, investing in speed delivers direct, clear returns.

Mohy's speed optimisation techniques

Speed doesn't come from a single "trick" but from dozens of optimisation techniques applied together. Mohy takes a holistic approach, optimising images, code, caching, servers and the CDN.

Image optimisation – Speed's enemy number one

Images make up 50–70% of the weight of most websites — the biggest factor in load time. Mohy applies a range of image optimisation techniques:

• WebP/AVIF formats – Modern image formats 30–50% lighter than JPEG/PNG at equal or better quality, supported by all modern browsers. Megabytes saved without customers noticing any loss in quality.
• Responsive images – The right image size for each device: small images (800px) for mobile, medium (1200px) for tablets and large (1920px) for desktops. No wasting bandwidth loading 4K images on a 6-inch phone screen.
• Lazy loading – Images load only when the visitor scrolls to them. Images at the bottom don't load with those at the top — saving significant bandwidth and initial load time. A page with 50 images loads only 5–10 at first.
• Image CDN – Images served from the server nearest the visitor. A visitor in Ho Chi Minh City gets images from Singapore, one in Hanoi from Hong Kong — much faster than from the US or Europe.
• Placeholders & progressive loading – A blurred placeholder (blur-up) or grey frame shows while images load, avoiding layout shift when images suddenly appear.

Clean, thoroughly optimised code

Code is the skeleton of a website. Clean, lean code = a fast site. Bloated code = a slow site. Mohy follows strict code optimisation principles:

• Minified CSS/JS – Compress code by removing whitespace, comments and unnecessary characters. A 100KB CSS file can shrink to 60KB — 40% less with identical functionality.
• Tree shaking – Ship only the code actually used. No loading a 500KB library when you need one 5KB function — especially important with modern JavaScript frameworks.
• Critical CSS – The CSS needed to render the top of the page (above the fold) is inlined in the HTML and loads instantly; the rest loads asynchronously. Result: the top of the page appears extremely fast.
• Async/defer scripts – JavaScript doesn't block rendering. Non-critical scripts load after the page appears (defer) and independent scripts load in parallel (async). Users see content immediately without waiting for JS.
• Code splitting – Code split into small files, loading only what the current page needs. The homepage doesn't load cart code; product pages don't load checkout code.

Smart multi-layer caching

Caching stores already-loaded data so the next visit doesn't load it again. Mohy sets up a 3-layer caching system:

• Browser caching – The browser stores CSS, JS, images and fonts. Second visits load almost instantly because the data is already on the visitor's device.
• CDN caching – Site content is stored on hundreds of servers worldwide. Each region has a nearby copy, cutting transfer time significantly.
• Server-side caching – Server results are stored. Later requests for the same content return immediately without reprocessing — less server load, faster responses.

Result: return visits load almost instantly (under 0.5 seconds). Coming back again and again = a great experience.

High-quality servers & hosting

A good server is the foundation of a fast site. Mohy uses stable hosting with 99.9% uptime, with servers close to Vietnamese users (Singapore, Hong Kong) to reduce latency. HTTP/2 loads many resources in parallel, and Brotli compression cuts transfer size by a further 15–20% over traditional Gzip.

For high-traffic sites, Mohy uses edge computing — processing at the nearest server rather than sending requests to the origin. Result: responses 3–5 times faster than ordinary hosting.

Core Web Vitals – The 3 metrics Google measures

Since 2021, Google has used Core Web Vitals as an official ranking factor. These 3 metrics measure real user experience:

• LCP (Largest Contentful Paint) – How long the main content (the largest image or main text block) takes to appear. Mohy's target: under 2.5 seconds, aiming for under 1.5. Influenced by image size, server speed and render-blocking resources.
• INP (Interaction to Next Paint) – Time from a user interaction (click, tap, keypress) to the page's visual response. Target: under 200ms. It replaced FID in March 2024 and measures every interaction, not just the first.
• CLS (Cumulative Layout Shift) – Layout stability: the page doesn't "jump" when images, ads or fonts load. Target: under 0.1. Techniques: set image width/height, preload fonts and reserve space for ads.

Speed directly affects business

This isn't empty theory — these figures are backed by real data from leading companies worldwide:

• Each second of delay = 7% fewer conversions. A site loading in 5 seconds loses about 35% of customers compared with one loading in 1 second. At 100 million VND monthly revenue, speed optimisation could add 20–35 million VND just by keeping visitors on the page.
• Amazon: internal research found every 100ms of delay cut revenue by 1%. At Amazon's scale, 100ms ≈ 1.6 billion USD a year — proof that every millisecond counts.
• Google: speed is an official ranking factor. Faster sites are favoured in search = more free traffic = more customers.
• Google Ads: a fast landing page = higher Quality Score = lower cost per click (CPC) = higher ROI. Slow sites are "penalised" by Google Ads with CPC 20–50% higher.
• Mobile commerce: 79% of shoppers unhappy with a slow mobile purchase are less likely to return. With over 70% of traffic on mobile, phone speed is vital.

Comparison: Fast vs. slow websites

Criteria	Fast site (under 2s)	Slow site (over 4s)
Bounce rate	20–30%	50–70%
Conversion rate	High and stable	Down 7% per second of delay
Google SEO	Favoured in rankings	Penalised in rankings
User experience	Smooth and professional	Frustrating, loses trust
Google Ads cost	High Quality Score → low CPC	Low Quality Score → high CPC
Time on site	3–5 minutes on average	Under 1 minute
Pages per session	4–6 pages	1–2 pages
Brand impression	Professional and trustworthy	Amateur and untrustworthy
Return likelihood	High (60–70%)	Low (20–30%)

Competitive advantage – When speed creates a virtuous circle

Most small and medium-sized business websites in Vietnam load slowly and aren't optimised for mobile. Surveys show over 70% of SME websites score under 50/100 on mobile PageSpeed. That's your advantage.

When your site is faster than competitors', a virtuous circle begins: customers have a better experience → stay longer → buy more → Google receives positive signals (low bounce rate, high dwell time) → ranks you higher → even more customers. And the circle continues.

Competitors with slow sites fall into a vicious circle: visitors leave quickly → Google rates them lower → rankings drop → less traffic → more spending on ads → lower ROI. Your website's speed decides which circle you're in.

Technology Mohy uses

Speed optimisation by industry

Future automation of speed optimisation

• AI performance optimisation – AI analyses user behaviour to predict the next page and preload it. Result: near-instant page transitions with no sense of waiting.
• Adaptive loading – The site adjusts content quality to network speed and device. Slow 3G → smaller images, less animation. Fast Wi-Fi → full quality and rich effects. Everyone gets the best possible experience.
• Edge computing – Site logic processed at the server nearest the user instead of a distant origin, keeping every response under 50ms.
• Automated performance testing – A CI/CD pipeline tests speed on every change. New code that slows the site → automatic alert and blocked deployment, so speed never degrades over time.
• HTTP/3 & QUIC – The next-generation transport protocol, faster than HTTP/2 especially on networks with packet loss. Mohy sites are ready to upgrade as HTTP/3 spreads.

Speed optimisation process

Mohy doesn't just "build fast from the start" — we have a process of measuring, optimising and continuous monitoring to keep speed up to standard.

1. Audit – Measure current speed with Google PageSpeed Insights, Lighthouse, GTmetrix and WebPageTest. Analyse every bottleneck: heavy images, render-blocking CSS/JS, slow servers and slow fonts. Prioritise by highest impact.
2. Complete image optimisation – Compress all images, convert to WebP/AVIF and configure lazy loading, responsive images and an image CDN. Set up an automatic pipeline for new uploads. Image weight cut by 50–70%.
3. Thorough code optimisation – Minify CSS/JS, tree-shake unused code, inline critical CSS, async/defer JavaScript and split code by page. Remove unnecessary plugins and libraries. Code weight cut by 40–60%.
4. Caching & CDN – Configure optimal browser caching (cache headers), deploy a CDN with edge caching and server-side caching for dynamic content, with automatic cache invalidation when content changes.
5. Passing Core Web Vitals – Measure and optimise LCP, INP and CLS on mobile and desktop. Target: every metric "Good" (green) in Google PageSpeed Insights, tested across devices and network speeds.
6. Monitoring & continuous improvement – 24/7 speed monitoring with automatic alerts and monthly Core Web Vitals reports. Continuous optimisation using real data from Google Search Console and CrUX (Chrome User Experience Report).

Mohy's speed commitment