Cornerstone Bold
Cornerstone Bold is a BigCommerce theme by BigCommerce (Free). Tested on 2026-11-08 with Google Lighthouse via PageSpeed Insights on its own demo store, it scores 88 for mobile speed and 99 for desktop speed, 51/51 for SEO and 94/95 for accessibility (mobile/desktop, 0–100).
Mobile88

Desktop99

Scores
| Mobile | Desktop | |
|---|---|---|
| Speed | 88 | 99 |
| SEO | 51 | 51 |
| Accessibility | 94 | 95 |
| Best practices | 100 | 100 |
Single preset · measured 54 times since 2026-09-11 · Lighthouse via PageSpeed Insights · 0–100, 90+ is good.
Why not 100 — Cornerstone-Bold home page
Mobile
Speed 88 · 12 points to gain
- −11 Largest Contentful Paint medium effort
- −0.6 Speed Index medium effort
- −0.5 First Contentful Paint medium effort
- 150 ms Reduce unused JavaScript high effort
SEO 54 · 46 points to gain
- −31 Page is blocked from indexing low effort
- −7.7 Document does not have a meta description low effort
- −7.7 Links do not have descriptive text low effort
Accessibility 88 · 12 points to gain
- −3.4 Background and foreground colors do not have a sufficient contrast ratio. medium effort
- −3.4 Links do not have a discernible name medium effort
- −3.4 Touch targets do not have sufficient size or spacing. medium effort
- −1.5 Document does not have a main landmark. medium effort
Desktop
Speed 99 · 1 points to gain
- −0.8 Largest Contentful Paint medium effort
SEO 54 · 46 points to gain
- −31 Page is blocked from indexing low effort
- −7.7 Document does not have a meta description low effort
- −7.7 Links do not have descriptive text low effort
Accessibility 92 · 8 points to gain
- −3.4 Links do not have a discernible name medium effort
- −3.4 Touch targets do not have sufficient size or spacing. medium effort
- −1.5 Document does not have a main landmark. medium effort
Presets and pages
| Preset / page | Speed | SEO | A11y | Speed | SEO | A11y | Tested |
|---|---|---|---|---|---|---|---|
| mobile | desktop | ||||||
| Cornerstone-Bold default demo ↗ | 88 | 51 | 94 | 99 | 51 | 95 | 2026-11-07 |
| category ↗ | 86 | 54 | 97 | 99 | 54 | 97 | 2026-11-08 |
| home ↗ | 88 | 54 | 88 | 99 | 54 | 92 | 2026-11-07 |
| product ↗ | 90 | 46 | 96 | 100 | 46 | 96 | 2026-11-08 |