Casper
Casper is a Astro theme by Antony Leons (Free). Tested on 2026-09-12 with Google Lighthouse via PageSpeed Insights on its own demo store, it scores 77 for mobile speed and 97 for desktop speed, 100/100 for SEO and 90/89 for accessibility (mobile/desktop, 0–100).
Mobile77
Desktop97
Scores
| Mobile | Desktop | |
|---|---|---|
| Speed | 77 | 97 |
| SEO | 100 | 100 |
| Accessibility | 90 | 89 |
| Best practices | 96 | 96 |
Single preset · measured 2 times since 2026-09-12 · Lighthouse via PageSpeed Insights · 0–100, 90+ is good.
Why not 100 — Casper home page
Mobile
Speed 77 · 23 points to gain
- −15.8 Largest Contentful Paint medium effort
- −6 First Contentful Paint medium effort
- −0.9 Speed Index medium effort
- 1.1 s Reduce unused JavaScript high effort
Accessibility 90 · 10 points to gain
- −3.4 Elements use prohibited ARIA attributes medium effort
- −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
Best practices 96 · 4 points to gain
- −3.8 Browser errors were logged to the console medium effort
Desktop
Speed 97 · 3 points to gain
- −3.5 Largest Contentful Paint medium effort
- 170 ms Reduce unused JavaScript high effort
Accessibility 89 · 11 points to gain
- −3.4 Elements use prohibited ARIA attributes medium effort
- −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
Best practices 96 · 4 points to gain
- −3.8 Browser errors were logged to the console medium effort
Presets and pages
| Preset / page | Speed | SEO | A11y | Speed | SEO | A11y | Tested |
|---|---|---|---|---|---|---|---|
| mobile | desktop | ||||||
| Casper default demo ↗ | 77 | 100 | 90 | 97 | 100 | 89 | 2026-09-12 |
| home ↗ | 77 | 100 | 90 | 97 | 100 | 89 | 2026-09-12 |
Show this score on your site
A live badge: it always shows Casper's current score and links back here. Paste this where the theme is sold or documented.
<a href="https://themestested.com/theme/astro/casper"><img src="https://themestested.com/badge/astro/casper.svg" alt="Casper speed score on Themestested" height="20"></a>
Add ?device=d for the desktop score, or ?metric=seo / ?metric=a11y for SEO or accessibility.