Masthead + EmDash CMS
Masthead + EmDash CMS is a Astro theme by ondelva (Free). Tested on 2026-11-10 with Google Lighthouse via PageSpeed Insights on its own demo store, it scores 99 for mobile speed and 100 for desktop speed, 100/100 for SEO and 100/100 for accessibility (mobile/desktop, 0–100).
Mobile99
Desktop100
Scores
| Mobile | Desktop | |
|---|---|---|
| Speed | 99 | 100 |
| SEO | 100 | 100 |
| Accessibility | 100 | 100 |
| Best practices | 100 | 100 |
Single preset · measured 6 times since 2026-09-26 · Lighthouse via PageSpeed Insights · 0–100, 90+ is good.
Why not 100 — Masthead + EmDash CMS home page
Mobile
Speed 99 · 1 points to gain
- −0.8 Largest Contentful Paint medium effort
Desktop
Every score is 100.
Presets and pages
| Preset / page | Speed | SEO | A11y | Speed | SEO | A11y | Tested |
|---|---|---|---|---|---|---|---|
| mobile | desktop | ||||||
| Masthead + EmDash CMS default demo ↗ | 99 | 100 | 100 | 100 | 100 | 100 | 2026-11-10 |
| home ↗ | 99 | 100 | 100 | 100 | 100 | 100 | 2026-11-10 |
Show this score on your site
A live badge: it always shows Masthead + EmDash CMS's current score and links back here. Paste this where the theme is sold or documented.
<a href="https://themestested.com/theme/astro/masthead"><img src="https://themestested.com/badge/astro/masthead.svg" alt="Masthead + EmDash CMS speed score on Themestested" height="20"></a>
Add ?device=d for the desktop score, or ?metric=seo / ?metric=a11y for SEO or accessibility.