dennerle.com website review

Your mobile performance score is 83. Pages that score under 90 lose visitors before the first paint.

2 files block the first paint until they finish downloading. Deferring or inlining them could save about 500 ms.

8 images could be 427 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

6 long tasks block the main thread while loading, the longest for 262 ms. During a long task the page ignores taps.

A phone's processor spends 2.5 s on main-thread work while loading, 821 ms of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

The page has 1,776 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

6 third-party services load with your homepage (Google Tag Manager, Shopify and shop.app and others), adding 367 KiB and 351 ms of main-thread time.

About 37 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 260 ms faster on a phone.

About 101 KiB of JavaScript is downloaded but never used on this page.

3 files are served with short cache lifetimes, so returning visitors download them again (5 KiB).

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.

3 KiB could be saved by minifying JavaScript.

The page becomes fully interactive after 8.1 s. Good is under 3.8 s.

Your largest element takes 4.0 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image.

Visually, the page fills in at 3.6 s (Speed Index). Good is under 3.4 s.

1 image 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 88 ms to 105 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 0.9 s to 0.9 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 2.3 MB in 191 requests on a phone: other files 889 KiB (121), images 776 KiB (22) and scripts 465 KiB (39). Under 2 MB keeps phones on slow connections fast.

3 images (110 KiB) are 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 0.65 g of CO₂e: 77.6 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

1 text element doesn't have enough contrast against the background to read easily, especially outdoors on a phone.

All page content should be contained by landmarks: 1 element on the page fails this check, rated moderate by axe-core.

12 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. (3 elements).

No structured data (JSON-LD), so Google can't show rich results such as your logo, ratings or FAQs.

The homepage links to 82 pages on dennerle.com and 8 external pages.

There is no Organization (or LocalBusiness) JSON-LD, so search engines and AI assistants have no machine-readable facts about who runs the site: its name, logo, profiles and contact details.

/customer_authentication/redirect has no <title>, so Google invents the link text in results.

/customer_authentication/redirect is marked noindex but linked from your homepage. If it is meant to be found, remove the noindex.

/customer_authentication/redirect, /en/blogs/guide and /en/blogs/recipe-aquarium have no meta description, so Google writes the search snippet from whatever text it finds.

Your homepage links to 1 page by a URL that isn't its canonical one, for example /blogs/ratgeber/das-ultimative-aquascape, whose canonical is /en/blogs/guide/das-ultimative-aquascape. Linking straight to the canonical URL saves crawlers a detour and keeps ranking signals on one address.

/customer_authentication/redirect and /en/pages/new-nano have no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 41 found) and read each the way a search engine does.

4 of 14 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

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

3 links go through two or more redirects, for example https://dennerle.com/customer_authentication/redirect?locale=en&region_country=DE.

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.

dennerle.com has no CAA record, so any certificate authority may issue a certificate for it. A CAA record naming your provider (for example letsencrypt.org) closes that door.

dennerle.com's DNS answers are not signed. DNSSEC stops attackers forging them to send visitors or email elsewhere; most registrars switch it on in a click, though most sites still run without it.

No testimonials, customer logos, ratings or customer counts on the homepage: nothing tells a new visitor that others already trust you.

No analytics or tag manager detected in the HTML, so you can't measure whether any of these fixes work.

No phone number or email link on the homepage, so ready-to-buy visitors have one fewer way to reach you.

The homepage has only about 157 words of visible text; thin pages give Google and first-time buyers little to go on.

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

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 Analytics, Google Tag Manager and Meta Pixel (measured from a US location before any click). No consent tool was detected. Visitors from the EU, UK and several US states must be asked first.

Opening the homepage sets 12 cookies (measured from a US location before any click).

No known cookie consent tool loads with the page. Some sites build their own banner, and some only show one to visitors from the EU.

Loading the homepage contacts 14 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.