Performance

How I got Wax London's homepage on screen sooner

On a phone, the hero went from 3.0s to 2.2s, which meets Google's good mark. On a computer it went from 3.2s to 2.8s. The header jump on a phone went to zero.

Client
Wax London
Lab
WebPageTest
Page
Homepage
Dates
Mar to May 2025
Live site
waxlondon.com
−12.5%
Desktop Largest Contentful Paint
3.2s to 2.8s
0
Mobile Cumulative Layout Shift
0.003 to 0
0.002
Desktop Cumulative Layout Shift
0.002 to 0.002
  • WebPageTest
  • Shopify
  • Liquid
  • JavaScript

Problem The first screen was late

I worked with Wax London on a homepage that had one job before anything else: show the hero. If that photo is late, or the top of the page jumps, people wait, then the brand feels slow.

That is a common first-screen problem on fashion homepages. The hero is the largest paint. Two announcement bars with different heights make the header drop. Third-party scripts for analytics, consent, and tests then compete with that first screen.

I measured the homepage in WebPageTest, on a phone and on a computer, then shipped the changes that would move Largest Contentful Paint and Cumulative Layout Shift. The live page is waxlondon.com.

If the hero lands sooner and the announcement bar keeps a steady height, the first screen should feel stable and ready, instead of late and twitchy.

On a phone, Largest Contentful Paint went from 3.0s to 2.2s. That is 26.7% faster, and it meets Google’s good threshold of 2.5s. The hero is now on screen by three seconds. That frame was missing in the before filmstrip.

On a computer, Largest Contentful Paint went from 3.2s to 2.8s. That is 12.5% faster. It is closer to 2.5s. It is not there yet.

These figures are lab runs, not Chrome User Experience Report field data.

Work What I changed

This was not a theme rewrite. I went after the first screen.

01

Got the hero on screen sooner

Largest Contentful Paint moved on both devices. On a phone the hero is now visible by three seconds, which the old filmstrip never showed.

02

Matched the announcement bars

The theme bar and the global bar had different heights. When one replaced the other, the page jumped. Same height on both, and the jump stopped.

03

Left desktop shift alone

Desktop Cumulative Layout Shift was already 0.002. CookieScript still adds a little. I did not chase a number that was already inside the budget.

04

Checked the leftover script cost

A blocked-script run showed Triple Whale, CookieScript, and Convert still cost Speed Index and Largest Contentful Paint. That is leftover work, not a live change.

Results What moved

WebPageTest on the homepage. Phone and computer. The phone now meets the Largest Contentful Paint bar. Desktop is closer. Layout shift on a phone is gone.

Phone

2.2s

Largest paint

from 3.0s

Computer

2.8s

Largest paint

from 3.2s

Phone

0

Layout shift

from 0.003

Computer

0.002

Layout shift

already inside budget

Largest paint

Largest Contentful Paint is the moment the main content shows up. On this homepage that is the hero. Mobile now meets Google's good mark. Desktop is still 0.3s over 2.5s.

Metric
Before
After
Difference
Mobile Largest Contentful Paint
3.0s
2.2s
−26.7%
Desktop Largest Contentful Paint
3.2s
2.8s
−12.5%

Mobile after is 27 March to 28 March 2025. Lab data, not field data.

Phone · Largest paint

WebPageTest mobile comparison: homepage Largest Contentful Paint moves from 3.0s before to 2.2s after, with the hero on screen by three seconds.

2.2s on a phone

Before, the first meaningful hero frame sat at 3.0s. After, it sits at 2.2s. That is inside Google's 2.5s good mark. People see the jacket, not a blank phone screen.

26.7% faster

Computer · Largest paint

WebPageTest desktop comparison: homepage Largest Contentful Paint moves from 3.2s before to 2.8s after.

2.8s on a computer

The same hero moved from 3.2s to 2.8s. That is better. It is still 0.3s over the 2.5s target. Desktop still needs image and script work to close that gap.

12.5% faster

Layout shift

The theme announcement bar and the global announcement bar were not the same height. When the global bar took over, the page dropped. Matching the heights removed the mobile jump. Desktop shift was already 0.002, well inside the 0.1 budget.

Metric
Before
After
Difference
Mobile Cumulative Layout Shift
0.003
0
Resolved
Desktop Cumulative Layout Shift
0.002
0.002
No change

CookieScript still adds a little desktop shift. I did not spend the next week shaving 0.002.

Phone · Layout shift

Bar chart of Cumulative Layout Shift on the homepage phone run. Before is about 0.003, after is near zero as of 28 March.

The jump is gone

Same height on the theme bar and the global bar. The first screen stays put. People can tap a link without the header sliding out from under their thumb.

0 layout shift on a phone

Takeaway What this means

This is the kind of homepage work I do for Shopify stores. I get the hero on screen, keep the header still, then measure what third-party scripts still cost.

Triple Whale, CookieScript, and Convert still sit on this homepage. I blocked them in a WebPageTest diagnostic, not on the live site. Speed Index dropped from 6.603s to 2.838s. Largest Contentful Paint dropped from 3.129s to 2.375s. That leftover cost is why a store can win the hero and still feel unfinished.

The domains were api.config-security.com, whale.camera, geo.cookie-script.com, cdn-4.convertexperiments.com, and conf.config-security.com. Start render stayed at 1.400s either way. The tax is visual completeness and largest paint, not the first pixel. Stores that have to keep those tools can still load them after the first screen.

Metric
Scripts on
Scripts blocked
Difference
Speed Index
6.603s
2.838s
−57.0%
Largest Contentful Paint
3.129s
2.375s
−24.1%
Cumulative Layout Shift
0.002
0
Resolved
Total Blocking Time
0.387s
0.352s
−9.0%

Before · Scripts on

WebPageTest with Triple Whale, CookieScript, and Convert still loading. Speed Index 6.603s, Largest Contentful Paint 3.129s, Cumulative Layout Shift 0.002.

With the third parties

Speed Index 6.603s. Largest Contentful Paint 3.129s. Cumulative Layout Shift 0.002. Total Blocking Time 387ms. The filmstrip is still filling in at 3 seconds.

6.603s Speed Index

After · Scripts blocked

WebPageTest with Triple Whale, CookieScript, and Convert blocked. Speed Index 2.838s, Largest Contentful Paint 2.375s, Cumulative Layout Shift 0.

Without those three

Speed Index 2.838s. Largest Contentful Paint 2.375s. Cumulative Layout Shift 0. Total Blocking Time 352ms. The hero is in the filmstrip by 2.5 seconds.

2.838s Speed Index

Work with me

Is your first screen late too?

I audit Shopify pages and ship loading work that makes the first screen usable.

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