winterthur.org website review

16 images could be 5.3 MB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 3.3 s faster on a phone.

71 files block the first paint until they finish downloading. Deferring or inlining them could save about 3.5 s.

About 456 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 2.4 s faster on a phone.

32 files are served with short cache lifetimes, so returning visitors download them again (416 KiB).

Your mobile performance score is 36 (desktop: 48). Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

8 third-party services load with your homepage (Google Tag Manager, Facebook and Brightcove and others), adding 1.1 MB and 1.5 s of main-thread time.

About 106 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 750 ms faster on a phone.

Google Tag Manager costs a phone 461 ms of main-thread work and 518 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.

Facebook costs a phone 377 ms of main-thread work and 307 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 3.9 s on main-thread work while loading, 2.0 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

Brightcove costs a phone 258 ms of main-thread work and 39 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.

Polyfills for old browsers add 42 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 200 ms faster on a phone.

13 long tasks block the main thread while loading, the longest for 191 ms. During a long task the page ignores taps.

25 KiB could be saved by minifying JavaScript.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 50 ms).

16 KiB could be saved by minifying CSS.

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 56.9 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “What's Happening …”.

The page becomes fully interactive after 60.2 s. Good is under 3.8 s.

The first text or image appears after 6.7 s on a phone. Good is under 1.8 s.

Visually, the page fills in at 9.5 s (Speed Index). Good is under 3.4 s.

Scripts block taps and scrolling for 892 ms in total while the page loads. Good is under 200 ms.

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' tap response (inp) went from 99 ms to 137 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 16.8 MB in 244 requests on a phone: images 14.7 MB (48), scripts 1.3 MB (82) and fonts 478 KiB (10). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 4.76 g of CO₂e: 570.7 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

11 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.

ARIA input fields must have an accessible name: 1 element on the page fails this check, rated serious by axe-core.

Links must have discernible text: 1 element on the page fails this check, rated serious by axe-core.

All page content should be contained by landmarks: 4 elements on the page fail this check, rated moderate by axe-core.

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

Landmarks should have a unique role or role/label/title (i.e. accessible name) combination: 1 element on the page fails this check, rated moderate by axe-core.

ARIA role should be appropriate for the element: 2 elements on the page fail this check, rated minor by axe-core.

Elements marked as presentational should be consistently ignored: 2 elements on the page fail this check, rated minor by axe-core.

No Open Graph image, so links shared on LinkedIn, Slack or Facebook show no preview picture.

4 links have no real href, so search engines can't follow them.

1 link use generic text like “click here” or “learn more”, which tells Google nothing about the page behind it.

The homepage links to 97 pages on winterthur.org and 14 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.winterthur.org/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.winterthur.org/family-2 has 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 https://www.winterthur.org/family-2, whose canonical is https://www.winterthur.org/fun-for-families. Linking straight to the canonical URL saves crawlers a detour and keeps ranking signals on one address.

https://www.winterthur.org/exhibitions-and-collections/library and https://www.winterthur.org/family-2 took over 3 s to send their HTML from our server.

We fetched 15 pages linked from your homepage (of 61 found) and read each the way a search engine does.

7 of 21 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

2 errors were logged to the browser console while the page loaded, for example “Cannot set properties of null (setting 'innerHTML')”.

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

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 1,086 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, Hotjar and Meta Pixel and 3 mores (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 27 cookies, 1 of them by other companies (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 36 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.