cerus.com website review

6 files block the first paint until they finish downloading. Deferring or inlining them could save about 4.0 s.

About 254 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 1.5 s faster on a phone.

Your mobile performance score is 55 (desktop: 80). Pages that score under 90 lose visitors before the first paint.

11 files are served with short cache lifetimes, so returning visitors download them again (157 KiB).

Google Tag Manager costs a phone 196 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.

A phone's processor spends 2.0 s on main-thread work while loading, 1.1 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

7 third-party services load with your homepage (Google Tag Manager, Optanon and Hubspot and others), adding 596 KiB and 384 ms of main-thread time.

Polyfills for old browsers add 22 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 200 ms faster on a phone.

6 long tasks block the main thread while loading, the longest for 209 ms. During a long task the page ignores taps.

About 45 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 150 ms faster on a phone.

Web fonts hide text while they load. Setting font-display: swap shows text immediately (about 150 ms).

13 KiB could be saved by minifying JavaScript.

Desktop scores 80 but mobile only 55. 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.

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

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 see the first content after 3.1 s (75th percentile). Good is under 1.8 s.

Real visitors wait 2.0 s for your server to start answering (75th percentile). Good is under 800 ms.

Your largest element takes 17.2 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “Pathogen Reduced Cryoprecipitated Fibrinogen Complex VISIT …”.

The first text or image appears after 6.1 s on a phone. Good is under 1.8 s.

The page becomes fully interactive after 17.2 s. Good is under 3.8 s.

Visually, the page fills in at 6.4 s (Speed Index). Good is under 3.4 s.

Real visitors wait 3.9 s for the largest content to appear (75th percentile). Good is under 2.5 s.

Real visitors wait 230 ms for the page to respond to a tap (75th percentile). Good is under 200 ms.

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' tap response (inp) went from 96 ms to 219 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' largest content (lcp) went from 2.2 s to 3.9 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Scripts block taps and scrolling for 237 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.

Your homepage downloads 2.5 MB in 49 requests on a phone: images 1.6 MB (11), scripts 707 KiB (17) and fonts 200 KiB (6). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 0.72 g of CO₂e: 86.5 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

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

Form elements should have a visible label: 1 element on the page fails this check, rated serious by axe-core.

All page content should be contained by landmarks: 6 elements on the page fail this check, rated moderate by axe-core.

The page has no <main> landmark, so screen-reader users cannot jump straight to the content.

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

Page should contain a level-one heading: 1 element on the page fails this check, rated moderate by axe-core.

Elements with visible text labels do not have matching accessible names. (1 element).

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.

5 links use generic text like “click here” or “learn more”, which tells Google nothing about the page behind them.

The homepage links to 32 pages on cerus.com and 57 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.

/careers/the-cerus-commitment-to-our-employees is marked noindex but linked from your homepage. If it is meant to be found, remove the noindex.

/about-cerus, /mission-and-values, /blood-matters, /leadership, /board-of-directors and /map-directions and 7 others have no meta description, so Google writes the search snippet from whatever text it finds.

/products, /cookie-notice, /legal-policy and /privacy-policy have no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 13 pages linked from your homepage and read each the way a search engine does.

13 of 50 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 read properties of null (reading '0')”.

http://cerus.com does not redirect to https, so some visitors land on the insecure version.

1 link go through two or more redirects, for example https://interceptbloodsystem.com/en.

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

cerus.com is registered until Dec 2026. Make sure auto-renew is on and the card on file is current.

cerus.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.

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.

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

Your phone number appears as text but isn't a tel: link, so phone visitors can't tap to call.

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 592 words of visible text.

We found no DKIM key on the selectors the big email providers use. If you send through one of them, turning on DKIM signing improves delivery.

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 HubSpot (measured from a US location before any click). A consent tool (OneTrust) is installed; check it blocks these until visitors agree where the law requires it.

Opening the homepage sets 8 cookies (measured from a US location before any click).

Loading the homepage contacts 15 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.