rotronic.com website review

5 files block the first paint until they finish downloading. Deferring or inlining them could save about 1.3 s.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 1.1 s).

Your mobile performance score is 37 (desktop: 68). Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

8 files are served with short cache lifetimes, so returning visitors download them again (198 KiB).

About 160 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 900 ms faster on a phone.

2 images could be 146 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 750 ms faster on a phone.

1 long task block the main thread while loading, the longest for 750 ms. During a long task the page ignores taps.

A phone's processor spends 2.0 s on main-thread work while loading, 1.4 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

Desktop scores 68 but mobile only 37. A gap that wide usually means heavy scripts and images that hit phones hardest.

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

Real Chrome users on phones do not pass Google's Core Web Vitals on this page (28-day field data from the Chrome UX Report (opens in a new tab)). Google uses this in ranking.

Real visitors wait 5.5 s for the largest content to appear (75th percentile). Good is under 2.5 s.

Real visitors see the first content after 4.8 s (75th percentile). Good is under 1.8 s.

Real visitors wait 4.0 s for your server to start answering (75th percentile). Good is under 800 ms.

Your largest element takes 7.4 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image “Rotronic is Part of DwyerOmega”. Most of its time is element render delay (3.8 s).

The layout shifts by 0.484 while loading, so content jumps under the reader's thumb. Good is under 0.1.

The page becomes fully interactive after 11.7 s. Good is under 3.8 s.

Visually, the page fills in at 8.1 s (Speed Index). Good is under 3.4 s.

Scripts block taps and scrolling for 350 ms in total while the page loads. Good is under 200 ms.

The first text or image appears after 2.3 s on a phone. Good is under 1.8 s.

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

Over the last 25 four-week periods to 2026-10-17, real Chrome visitors' tap response (inp) went from 119 ms to 127 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-17, real Chrome visitors' largest content (lcp) went from 4.6 s to 5.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

1 image (168 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 0.31 g of CO₂e: 37.2 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

3 buttons have no accessible name, so screen readers announce just “button”.

Certain ARIA roles must contain particular children: 1 element on the page fails this check, rated critical by axe-core.

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

Interactive controls must not be nested: 2 elements on the page fail this check, rated serious by axe-core.

ARIA dialog and alertdialog nodes should have an accessible name: 1 element on the page fails this check, rated serious by axe-core.

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

All page content should be contained by landmarks: 3 elements on the page fail this check, rated moderate by axe-core.

The viewport tag blocks pinch-zoom, which low-vision visitors rely on.

No meta description, so Google writes its own snippet from whatever text it finds.

There is no <h1>, so neither visitors nor Google get a clear main headline.

Your title is 96 characters, so Google will cut it off around 60: “Measurement Solutions - Humidity, Temperature, CO2 and Differential Pressure Measurement …”.

Structured data found (WebPage and WebSite) but with 2 problems, for example “WebSite: missing name”.

No Open Graph image (also missing: og:description), so links shared on LinkedIn, Slack or Facebook show no preview picture.

No XML sitemap at https://www.rotronic.com/sitemap.xml, so Google discovers your pages only by following links.

No twitter:card tag. X falls back to Open Graph, which is incomplete here.

The homepage links to 125 pages on rotronic.com and 19 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.

There is no https://www.rotronic.com/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.

https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/standard-high-precision-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/industrial-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/high-temperature-handheld-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/usb-probe and https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/miniature-probes and 4 others all use the title “Humidity Probes | Humidity Sensors | Relative Humidity Probe”. Search engines can't tell which page to show for a search, so each competes with the others.

https://www.rotronic.com/en, https://www.rotronic.com/en-us/catalogsearch/advanced and https://www.rotronic.com/en-us/about-us/about-rotronic-ueber-rotronic have no meta description, so Google writes the search snippet from whatever text it finds.

https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/standard-high-precision-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/industrial-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/high-temperature-handheld-probes, https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/usb-probe and https://www.rotronic.com/en-us/humidity-measurement-feuchtemessung-temperaturmessungs/humidity-measurement-feuchte-messung/probes-filters/miniature-probes and 4 others use the same meta description. A description written for each page earns more clicks.

https://www.rotronic.com/en has no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 116 found) and read each the way a search engine does.

14 of 37 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

The page uses 1 deprecated browser API that will stop working in future browsers (“Synchronous `XMLHttpRequest` on the main thread is deprecated because of its detrimental effects to…”).

7 images are displayed at the wrong aspect ratio, so they look stretched or squashed.

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

Your homepage shows a street address but no LocalBusiness JSON-LD, so Google and AI assistants have to guess your address, hours and phone from the page text.

The homepage has only about 222 words of visible text; thin pages give Google and first-time buyers little to go on.

The homepage shows no opening hours. If customers visit or call, show when.

There is no link to Google or Apple Maps. A directions link is one tap for a phone visitor.

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

Opening the homepage sets 8 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.