Marketplace speed

What moved

Mobile

First Contentful Paint

6.2s→2.1s−4.1s

Cumulative Layout Shift

0.318→0.002−0.316

Page transfer

4.9MB→4.0MB−0.9MB

Speed Index

15.5s→7.2s−8.3s

Desktop

First Contentful Paint

1.7s→0.7s−1.0s

Largest Contentful Paint

5.6s→1.4s−4.2s

Page transfer

5.0MB→4.4MB−0.6MB

Total Blocking Time

170ms→150ms−20ms

What we changed

Open one for tickets, mechanism and files.

The space photo is the biggest thing on the screen. The browser now knows that before it starts fetching, and phones get a phone-sized file instead of a desktop one.

Session recording and the marketing chat widget were doing work on the main thread while the page was still trying to render. Both now wait their turn.

The font stack was serving formats no current browser asks for. Separately, hashed build files were being re-downloaded on every visit instead of reused.

Opening a space with stale server-rendered data used to request the same space twice, once from the page and once from the store.

How we measured

Lighthouse 13.4.1 · navigation mode · /space/north-perth-town-hall · fetched 10 September 2026

Caveats

This is not a clean A/B. The staging reports warned that IndexedDB may have affected the run, which can mean a repeat-visit cache. The develop reports carried no such warning.
Different hosts and environments, same space slug. Staging and develop are not identical infrastructure.
Mobile Total Blocking Time got worse, 1,230ms to 1,400ms. Work moved off the critical path, but the main thread is still busy.
Mobile Time to Interactive is still about 24 seconds. Down from 34, and nowhere near fixed.
Desktop time to first byte is still slow. The root document went from roughly 1.14s to 0.91s.

Before: client-staging.spaceto.co/space/north-perth-town-hall
After: spacetoco.dev/space/north-perth-town-hall

Lighthouse 13.4.1 · one run per environment
Metric	Before · staging	After · develop
Mobile
Performance	15	57
First Contentful Paint	6.2s	2.1s
Largest Contentful Paint	25.0s	3.5s
Total Blocking Time	1,230ms	1,400ms
Cumulative Layout Shift	0.318	0.002
Speed Index	15.5s	7.2s
Time to Interactive	34.3s	24.2s
Transfer	4,922 KiB	4,022 KiB
Unused JS (est.)	792 KiB	610 KiB
Main-thread work	11.0s	4.8s
Accessibility	83	93
Desktop
Performance	57	87
First Contentful Paint	1.7s	0.7s
Largest Contentful Paint	5.6s	1.4s
Total Blocking Time	170ms	150ms
Cumulative Layout Shift	0.063	0.054
Speed Index	3.4s	2.3s
Time to Interactive	5.6s	4.4s
Transfer	4,964 KiB	4,446 KiB
Accessibility	73	94

What moved

What we changed

01 The hero image loads first, and at phone size

02 Third-party scripts no longer run during the first paint

03 Less CSS on the first visit, real caching on the next

04 One data fetch on a cold load, not two

How we measured

Caveats