pacb.com website review

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

Your mobile performance score is 29. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 7.4 s on main-thread work while loading, 3.9 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

About 3.1 MB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 450 ms faster on a phone.

4 images could be 3.4 MB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

8 third-party services load with your homepage (Google CDN, Google Tag Manager and pacificbiosciences.com and others), adding 3.4 MB and 3.1 s of main-thread time.

Google CDN costs a phone 937 ms of main-thread work and 1.2 MB 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.

33 files are served with short cache lifetimes, so returning visitors download them again (520 KiB).

Google Tag Manager costs a phone 814 ms of main-thread work and 531 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.

pacificbiosciences.com costs a phone 477 ms of main-thread work and 667 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.

490 KiB could be saved by minifying JavaScript.

20 long tasks block the main thread while loading, the longest for 456 ms. During a long task the page ignores taps.

About 140 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 300 ms faster on a phone.

Accessibe Accessibility Overlay costs a phone 258 ms of main-thread work and 243 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.

The page has 1,960 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

FontAwesome CDN costs a phone 150 ms of main-thread work and 302 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.

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

Polyfills for old browsers add 32 KiB JavaScript that modern phones do not need.

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 CSS.

The page becomes fully interactive after 42.5 s. Good is under 3.8 s.

Your largest element takes 8.6 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the element shown below.

Scripts block taps and scrolling for 2.3 s in total while the page loads. Good is under 200 ms.

The first text or image appears after 4.2 s on a phone. Good is under 1.8 s.

Visually, the page fills in at 7.5 s (Speed Index). Good is under 3.4 s.

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

Over the last 25 four-week periods to 2026-10-24, real Chrome visitors' tap response (inp) went from 123 ms to 117 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 1.8 s to 1.7 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 19.6 MB in 238 requests on a phone: media 8.9 MB (1), scripts 4.8 MB (97) and images 4.6 MB (43). Under 2 MB keeps phones on slow connections fast.

3 images weigh 3.5 MB together. On a phone connection a single image that size takes seconds.

3 images are downloaded at several times the size a phone draws them, for example HiFi-BioFx-Bootcamp-HP-Card-scaled.png at 2,560 px wide, shown at 364 px. Resized copies would save about 2.6 MB.

5 images further down the page (3.3 MB) download before anyone scrolls to them. Adding loading="lazy" lets the first screen load first.

By the Sustainable Web Design model, a visit to your homepage emits about 5.54 g of CO₂e: 665.3 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

Elements must only use permitted ARIA attributes: 2 elements on the page fail this check, rated serious by axe-core.

2 links inside paragraphs rely on colour alone to stand out.

1 element hidden from screen readers can still receive keyboard focus.

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: 4 elements on the page fail this check, rated moderate by axe-core.

Main landmark should not be contained in another landmark: 1 element on the page fails this check, rated moderate by axe-core.

Document should not have more than one main landmark: 1 element on the page fails this check, rated moderate by axe-core.

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.

8 visible links have no text or label, so screen readers cannot say where they go.

Headings should not be empty: 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.

Headings skip levels (h1 → h3), which makes the page harder to scan with a screen reader.

Your meta description is 215 characters; Google truncates after about 160, so the end of your pitch is cut.

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

1 link has no real href, so search engines can't follow it.

Your <h1> is empty.

The homepage links to 433 pages on pacb.com and 33 external pages.

Your Organization JSON-LD is missing sameAs (social profiles), description and contact details. These are the facts AI assistants use to describe a business and to tell it apart from others with a similar name.

There is no https://www.pacb.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.pacb.com/products-and-services/consumables/application-kits 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.pacb.com/products-and-services/sequencing-systems, whose canonical is https://www.pacb.com/sequencing-systems. Linking straight to the canonical URL saves crawlers a detour and keeps ranking signals on one address.

We fetched 15 pages linked from your homepage (of 133 found) and read each the way a search engine does.

2 third-party cookies are set on load; browsers are restricting these, so whatever relies on them breaks.

5 errors were logged to the browser console while the page loaded, for example “Failed to load resource: net::ERR_FAILED”.

Chrome logged issues while loading the page (“Cookie”).

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 732 words of visible text.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, Hotjar and LinkedIn Insight and 4 mores (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 20 cookies (measured from a US location before any click).

Loading the homepage contacts 55 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.