cerascreen.com website review

3 files block the first paint until they finish downloading. Deferring or inlining them could save about 3.4 s.

About 400 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 1.2 s faster on a phone.

Your mobile performance score is 59. Pages that score under 90 lose visitors before the first paint.

8 third-party services load with your homepage (Google Tag Manager, Shopify and Clarity and others), adding 1.6 MB and 689 ms of main-thread time.

16 files are served with short cache lifetimes, so returning visitors download them again (151 KiB).

A phone's processor spends 3.7 s on main-thread work while loading, 1.5 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

Google Tag Manager costs a phone 259 ms of main-thread work and 298 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.

24 images could be 264 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

Shopify costs a phone 124 ms of main-thread work and 853 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.

The page has 2,075 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

6 long tasks block the main thread while loading, the longest for 190 ms. During a long task the page ignores taps.

8 KiB could be saved by minifying JavaScript.

About 61 KiB of CSS is downloaded but never applied on this page.

11 KiB JavaScript is shipped twice across bundles.

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

Scripts make the browser recalculate the layout repeatedly while the page loads, which wastes processor time on phones.

Your largest element takes 10.4 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “Wir verwenden Cookies, um dir das bestmögliche Erlebnis auf…”. Most of its time is element render delay (6.2 s).

Visually, the page fills in at 10.6 s (Speed Index). Good is under 3.4 s.

The page becomes fully interactive after 11.3 s. Good is under 3.8 s.

The first text or image appears after 3.1 s on a phone. Good is under 1.8 s.

Over the last 25 four-week periods to 2026-11-07, real Chrome visitors' largest content (lcp) went from 2.1 s to 1.9 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 2.9 MB in 203 requests on a phone: scripts 1.1 MB (76), images 780 KiB (53) and other files 681 KiB (64). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 0.81 g of CO₂e: 97.4 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

1 element use ARIA attributes their role does not allow, which confuses screen readers.

28 text elements don't have enough contrast against the background to read easily, especially outdoors on a phone.

4 tap targets are too small or too close together to hit reliably with a finger.

[role="img"] and [role="image"] elements must have alternative text: 1 element on the page fails this check, rated serious by axe-core.

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

All page content should be contained by landmarks: 74 elements on the page fail this check, rated moderate by axe-core.

2 form fields have no label, so screen readers announce an empty box and autofill guesses.

ARIA role should be appropriate for the element: 5 elements on the page fail this check, rated minor by axe-core.

Headings skip levels (h1 → h3 and h3 → h6), which makes the page harder to scan with a screen reader.

Elements with visible text labels do not have matching accessible names. (9 elements).

There are 2 <h1> headlines (“Moderne Laboranalyse.Klarheit für deine Gesundhei…” and “Müde? Bauchbeschwerden?Finde heraus, was dahinter…”). One clear main headline is easier for people and search engines.

1 link has no real href, so search engines can't follow it.

The homepage links to 293 pages on cerascreen.com and 15 external pages.

/pages/versand-zahlung, /collections/testkits, /products/vitamin-d-test, /products/omega-3-test, /products/aminosaeuren-test and /products/cortisol-test and 9 others have no <h1> headline, so visitors and search engines get no clear main topic.

/pages/versand-zahlung, /products/vitamin-d-test, /products/omega-3-test, /products/aminosaeuren-test, /products/cortisol-test and /products/histamin-intoleranz-test and 8 others have under 150 words in the HTML. Thin pages rarely rank; if the text loads with JavaScript, crawlers that don't run it see even less.

We fetched 15 pages linked from your homepage (of 83 found) and read each the way a search engine does.

HSTS is set, but max-age is 91 days; one year is the recommended minimum.

1 link go through two or more redirects, for example https://mail.google.com/mail/u/0/.

No Referrer-Policy header, so full URLs can leak to the sites you link to.

No Permissions-Policy header to switch off camera, microphone and location for embedded content.

X-XSS-Protection is set to “1; mode=block”; the header is deprecated and can introduce bugs. Use 0 or remove it.

There is no /.well-known/security.txt telling researchers how to report a security problem to you.

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 702 words of visible text.

DMARC is set to p=none, so mail pretending to be cerascreen.com is still delivered. Reports are on, so moving to quarantine is the next step.

Email authentication: SPF record 25 points, plus 15 when it ends in -all (10 for ~all); DMARC record 25, plus 25 for a reject policy (15 for quarantine); a DKIM key on a common selector 10.

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

Opening the homepage sets 10 cookies (measured from a US location before any click).

Loading the homepage contacts 34 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.