Web Design & Development · ServiceMOFU
Website speed optimisation measured on real phones
The short answer
A Lighthouse score of 95 on a developer's laptop means very little. What matters is field data — how real visitors on real phones and networks experience the site. For most Indian audiences, that's a mid-range Android phone on a variable 4G or 5G connection.
PMG optimises against field Core Web Vitals and mobile conversion rate, because a site that's fast in the lab and slow in reality helps nobody.
The three metrics
- LCP (Largest Contentful Paint) — when the main content appears. Target under 2.5 seconds. Usually a hero image or headline.
- INP (Interaction to Next Paint) — how quickly the page responds to taps. Target under 200ms. Usually heavy JavaScript.
- CLS (Cumulative Layout Shift) — how much content jumps around. Target under 0.1. Usually images without dimensions or late-loading banners.
The usual culprits
- Uncompressed hero images served at desktop size to phones
- Third-party scripts — chat widgets, heatmaps, multiple pixels — loading before content
- Heavy page builders and unused CSS
- Web fonts blocking text rendering
- Images and embeds without reserved dimensions
- Too many apps or plugins each adding their own scripts
- No CDN, or a server far from Indian users
How we fix it
- Measure field data by template and device.
- Find the LCP element on key templates and make it fast — modern formats, right size, priority loading.
- Cut and defer scripts — remove what's unused, delay what isn't critical, move tracking server-side.
- Reserve space for images, embeds and banners.
- Optimise fonts — subset, preload and swap.
- Cache and CDN configuration.
- Re-measure field data after the 28-day window updates.
The usual causes of a slow site
- Uncompressed, oversized images and no modern formats
- Many third-party scripts — chat widgets, trackers, heatmaps, pop-ups
- Heavy themes and page builders loading unused code
- Render-blocking CSS and JavaScript
- Web fonts loaded inefficiently
- Slow server response and no caching or CDN
- Layout shifts from ads, embeds or late-loading images without dimensions
How we fix speed
- Measure field data (Search Console, CrUX) and lab data (Lighthouse) for key templates.
- Prioritise templates and pages by traffic and revenue.
- Quick wins — image compression, lazy loading, caching, script clean-up.
- Deeper fixes — critical CSS, code splitting, font strategy, server improvements.
- Protect — performance budgets and checks so speed doesn't regress.
Why lab and field scores differ
Lab tools (like PageSpeed Insights' Lighthouse section) run a single simulated test, so scores vary between runs. Field data reflects real users' devices and networks over 28 days. Decisions should be based on field data where available, using lab tests to diagnose causes.
Speed fixes by platform
| Platform | Common fixes |
|---|---|
| WordPress | Plugin cleanup, caching, image optimisation |
| Shopify | App reduction, theme code, images |
| JavaScript apps | Server rendering, code splitting |
| Custom sites | CDN, compression, critical CSS |
A worked example
A lead-generation site loaded slowly on mobile because of heavy images and third-party scripts. Compressing images, delaying non-essential scripts and adding a CDN brought load times down sharply, and form submissions rose.
Before speed optimisation
- Core Web Vitals field data
- List of third-party scripts
- Hosting and CDN details
- Pages that matter most
How a Website Speed Optimisation engagement with PMG runs
- Audit (week 0–1). Accounts, analytics, tracking, website, CRM flow and competitors reviewed, with a written list of what's broken, what's wasted and the three moves we'd make first.
- Plan (week 1–2). Break-even ROAS or a target cost per lead, a measurement plan and a 90-day roadmap for Website Speed Optimisation, with owners and dates.
- Launch (week 2–4). Clean structures, verified conversion signals, the first creative sprint and landing-page fixes.
- Optimise (months 2–3). A weekly test cadence, with budget following the cheapest incremental results rather than platform-reported ones.
- Scale (month 3 onwards). New channels, geographies and retention loops, added only when the economics hold.
Every week you get a one-page scorecard, a change log, the test board and a 30-minute call with your strategist. See how we work and pricing for details.
Why teams choose PMG for Website Speed Optimisation
- Measurement first. Unit economics and clean tracking come before any increase in spend.
- You own everything. Ad accounts, data and creative stay in your name; ad spend goes straight to the platforms.
- Senior hands on the account. The strategist you speak to is the person running it.
- Weekly transparency. Scorecard, change log and test board — every week.
- Short minimum terms. We keep clients with results, not contracts.
- India and international. One Mumbai team running campaigns across Indian cities and overseas markets, Mon–Sat, 7am–9pm IST.
Where we run Website Speed Optimisation
We manage Website Speed Optimisation for businesses across India — including Mumbai, Delhi NCR, Bengaluru, Pune, Hyderabad, Chennai, Kolkata and Ahmedabad — and for companies in the UAE, Saudi Arabia, the United States, the United Kingdom, Canada, Australia, Singapore and Germany. Campaigns are planned market by market, with language, currency, platform mix and privacy rules matched to each. See all Indian locations and international markets.
Free growth audit
Get a written audit for Website Speed Optimisation.
No sales call required. Tell us where to look; a strategist replies within working hours and sends the written audit within 72 hours.
- Tracking check
- Pixels, Conversions API, GA4 events and offline conversions — what is firing, what is double-counted, what is missing.
- Wasted spend
- Search terms, placements, audiences and overlap that cost money without producing qualified leads or sales.
- Conversion path
- Landing page speed, message match, form friction and follow-up time — where interested people drop off.
- 90-day priorities
- The three changes we would make first, with the metric each one should move.
Frequently asked questions
How much does speed affect conversions?
Meaningfully, especially on mobile. Slower pages lose visitors before they see your offer. The exact effect varies by site, which is why we measure conversion before and after.
Can you fix speed without a redesign?
Usually yes. Images, scripts, fonts and caching account for most problems and can be fixed in place.
Why does PageSpeed Insights show different numbers each time?
Lab tests vary run to run. Field data from real users is more stable and is what matters for search.
Does page speed affect Google rankings?
Page experience, including Core Web Vitals, is one of many signals. Speed rarely overrides relevance, but it can make a difference between similar pages — and it strongly affects conversion.
Which is more important: mobile or desktop speed?
Mobile, for most Indian audiences and because Google uses mobile-first indexing.
How much faster can our site get?
It depends on the causes. Image and script clean-ups often produce significant improvements; platform limitations may cap gains.
What is a good page load time?
Aim for Google's "good" Core Web Vitals, such as LCP under 2.5 seconds on mobile.
Do third-party scripts slow sites?
Often — chat widgets, trackers and embeds are common causes.
Will speed improvements increase conversions?
Faster pages generally convert better, especially on mobile.
How long does Website Speed Optimisation take to show results?
Tracking fixes and search campaigns often show improvement within two to four weeks; prospecting on Meta or YouTube usually needs three to six weeks of creative testing; SEO compounds over three to nine months. We agree leading indicators up front so progress is visible early.
Is there a long contract?
No. Minimum terms are short, because we would rather keep clients with results than with contracts.
Will we own the ad accounts and data?
Yes. Everything runs in your own accounts with partner access for PMG, and you can see it all at any time.
What do you need from us to start?
Access to ad accounts and analytics, your margins and order values (or deal values), brand assets, and a decision-maker available for a weekly 30-minute call.
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Find out where your budget is leaking.
Send us your ad account, analytics or site. Within 72 hours you get a written audit: tracking gaps, wasted spend, and the three moves we'd make first. No pitch deck.