cisl.cam.ac.uk website review

6 files are served with short cache lifetimes, so returning visitors download them again (533 KiB).

7 files block the first paint until they finish downloading. Deferring or inlining them could save about 3.1 s.

Your mobile performance score is 57. Pages that score under 90 lose visitors before the first paint.

About 229 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 460 ms faster on a phone.

Google Tag Manager costs a phone 388 ms of main-thread work and 536 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.

3 images could be 90 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 300 ms faster on a phone.

3 third-party services load with your homepage (Google Tag Manager, Google Analytics and Google/Doubleclick Ads), adding 538 KiB and 388 ms of main-thread time.

4 long tasks block the main thread while loading, the longest for 171 ms. During a long task the page ignores taps.

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

About 15 KiB of CSS is downloaded but never applied on this page.

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.

Your largest element takes 7.3 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image “A group of seven people sit in a bright, modern workspace, …”.

The first text or image appears after 3.5 s on a phone. Good is under 1.8 s.

The page becomes fully interactive after 8.9 s. Good is under 3.8 s.

Real visitors see the first content after 2.1 s (75th percentile). Good is under 1.8 s.

Real visitors wait 1.6 s for your server to start answering (75th percentile). Good is under 800 ms.

The layout shifts by 0.183 while loading, so content jumps under the reader's thumb. Good is under 0.1.

Visually, the page fills in at 3.5 s (Speed Index). Good is under 3.4 s.

Scripts block taps and scrolling for 202 ms in total while the page loads. Good is under 200 ms.

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

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' largest content (lcp) went from 2.4 s to 2.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

6-883x431.webp is on the first screen but marked loading="lazy", so the browser waits before fetching it and the page looks finished later. Load it eagerly (and give it fetchpriority="high" if it is the main image).

2 images are downloaded at several times the size a phone draws them, for example ucam-logo-colour-text-black.svg at 2,363 px wide, shown at 84 px. Resized copies would save about 301 KiB.

1 image further down the page (148 KiB) download before anyone scrolls to it. Adding loading="lazy" lets the first screen load first.

By the Sustainable Web Design model, a visit to your homepage emits about 0.46 g of CO₂e: 55.8 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

1 form field has no label, so screen readers announce an empty box and autofill guesses.

Elements with visible text labels do not have matching accessible names. (21 elements).

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

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

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

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

The homepage links to 226 pages on cisl.cam.ac.uk and 21 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 /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.

/contact-us-0 has no meta description, so Google writes the search snippet from whatever text it finds.

/innovation, /policy-and-finance, /community, /resources, /contact-us-0 and /cop-climate-change-conference and 4 others took over 3 s to send their HTML from our server.

We fetched 15 pages linked from your homepage (of 132 found) and read each the way a search engine does.

2 of 9 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

2 links to other sites are dead, for example https://web.cisl.cam.ac.uk/cn/arm1c/cislbrochure (404).

No Content-Security-Policy header, the main browser-side defence against injected scripts.

HSTS is set, but max-age is 0 days; one year is the recommended minimum.

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.

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

cam.ac.uk 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.

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

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.

A local customer looking to call finds no phone number on the homepage. Add one, ideally as a tap-to-call link.

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

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.

The homepage carries about 576 words of visible text.

Your SPF record doesn't end in -all or ~all, so it doesn't stop other servers sending as you: “v=spf1 include:mx.cam.ac.uk include:spf.protection.outlook.com include:spf.officernd.com include:spf.protection.outlook…”.

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 and Google Tag Manager (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.

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