sternglas.de website review

10 files are served with short cache lifetimes, so returning visitors download them again (313 KiB).

Your mobile performance score is 70. Pages that score under 90 lose visitors before the first paint.

8 third-party services load with your homepage (Google Tag Manager, Cookiebot and Clarity and others), adding 1.1 MB and 837 ms of main-thread time.

14 files block the first paint until they finish downloading. Deferring or inlining them could save about 850 ms.

12 images could be 216 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 400 ms faster on a phone.

Google Tag Manager costs a phone 368 ms of main-thread work and 532 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

A phone's processor spends 3.4 s on main-thread work while loading, 2.1 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

The page has 1,693 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

About 194 KiB of JavaScript is downloaded but never used on this page.

6 long tasks block the main thread while loading, the longest for 145 ms. During a long task the page ignores taps.

Polyfills for old browsers add 19 KiB JavaScript that modern phones do not need.

Critical files load one after another instead of in parallel (3 chains). Preconnecting to key origins and preloading the hero image shortens the chain.

3 KiB JavaScript is shipped twice across bundles.

Your largest element takes 6.8 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image.

The page becomes fully interactive after 15.2 s. Good is under 3.8 s.

Scripts block taps and scrolling for 262 ms in total while the page loads. Good is under 200 ms.

Visually, the page fills in at 3.7 s (Speed Index). Good is under 3.4 s.

6 images have no width and height attributes, so the layout jumps as each one loads.

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' tap response (inp) went from 103 ms to 96 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' largest content (lcp) went from 1.3 s to 1.1 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 3.3 MB in 308 requests on a phone: scripts 1.4 MB (94), other files 1.1 MB (155) and images 546 KiB (20). Under 2 MB keeps phones on slow connections fast.

1 image (79 KiB) is JPEG, PNG or GIF. The same pictures as WebP or AVIF are usually much smaller at the same quality, and every current browser shows them.

By the Sustainable Web Design model, a visit to your homepage emits about 0.92 g of CO₂e: 110.8 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

2 images have no alt text, which hurts accessibility and image search.

21 visible links have no text or label, so screen readers cannot say where they go.

Elements with visible text labels do not have matching accessible names. (6 elements).

The homepage links to 176 pages on sternglas.de and 15 external pages.

There is no https://www.sternglas.de/llms.txt, a short Markdown guide to your key pages for AI tools (llmstxt.org). It is optional and few AI tools read it yet, so treat it as a cheap extra.

We fetched 15 pages linked from your homepage (of 67 found) and read each the way a search engine does.

10 of 39 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

4 errors were logged to the browser console while the page loaded, for example “Failed to load resource: net::ERR_TUNNEL_CONNECTION_FAILED”.

On a phone, there is no call to action on the first screen: visitors have to scroll to find out what to do next.

We found no call-to-action buttons or links (such as “Book a demo” or “Get a quote”) anywhere on the homepage.

No guarantee or risk reducer (money-back, free trial, no credit card) is mentioned, which is often what tips a hesitant visitor.

The homepage carries about 418 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, Klaviyo and Meta Pixel and 1 more (measured from a US location before any click). A consent tool (Cookiebot) is installed; check it blocks these until visitors agree where the law requires it.

Opening the homepage sets 20 cookies (measured from a US location before any click).

Loading the homepage contacts 36 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.