bostonscientific.com website review

About 685 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 5.4 s faster on a phone.

32 files are served with short cache lifetimes, so returning visitors download them again (511 KiB).

Your mobile performance score is 45. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

8 third-party services load with your homepage (Vimeo, Google Tag Manager and Optanon and others), adding 1.7 MB and 865 ms of main-thread time.

About 171 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 600 ms faster on a phone.

5 files block the first paint until they finish downloading. Deferring or inlining them could save about 750 ms.

A phone's processor spends 3.6 s on main-thread work while loading, 1.8 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

Vimeo costs a phone 256 ms of main-thread work and 769 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 50 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 150 ms faster on a phone.

14 long tasks block the main thread while loading, the longest for 182 ms. During a long task the page ignores taps.

6 images could be 173 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

13 KiB could be saved by minifying CSS.

12 KiB could be saved by minifying JavaScript.

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 wait 4.6 s for the largest content to appear (75th percentile). Good is under 2.5 s.

Real visitors see the first content after 4.5 s (75th percentile). Good is under 1.8 s.

Your largest element takes 19.9 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “Advancing science for more morning runs Watch Lamburtus’s s…”.

The page becomes fully interactive after 19.9 s. Good is under 3.8 s.

Visually, the page fills in at 9.1 s (Speed Index). Good is under 3.4 s.

The first text or image appears after 3.3 s on a phone. Good is under 1.8 s.

Scripts block taps and scrolling for 633 ms in total while the page loads. Good is under 200 ms.

Real visitors wait 1.1 s for your server to start answering (75th percentile). Good is under 800 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 2026-11-07, real Chrome visitors' tap response (inp) went from 125 ms to 136 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-11-07, real Chrome visitors' largest content (lcp) went from 3.6 s to 4.0 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 3.4 MB in 71 requests on a phone: scripts 1.9 MB (22), fonts 776 KiB (7) and images 426 KiB (21). Under 2 MB keeps phones on slow connections fast.

old-men-running-in-yellow-tshirt-and-blue-shorts.jpg 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).

1 image (66 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 0.96 g of CO₂e: 115.1 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

1 frame has no title, so screen-reader users cannot tell what it contains.

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.

Elements with visible text labels do not have matching accessible names. (3 elements).

There are 2 <h1> headlines (“Advancing science for more morning runs” and “Advancing science for more family dinners”). One clear main headline is easier for people and search engines.

2 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.

The homepage links to 174 pages on bostonscientific.com and 17 external pages.

There is no https://www.bostonscientific.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.bostonscientific.com/en-US/home.html and / all use the title “Advancing Science for Life - US - Boston Scientific”. Search engines can't tell which page to show for a search, so each competes with the others.

Your homepage links to 2 pages by a URL that isn't their canonical one, for example /, whose canonical is https://www.bostonscientific.com/en-US/home.html. 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 138 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.

The page uses 1 deprecated browser API that will stop working in future browsers (“Unload event listeners are deprecated and will be removed.”).

1 error was logged to the browser console while the page loaded, for example “Cannot read properties of undefined (reading 'getAttribute')”.

1 image is served at too low a resolution for sharp phone screens.

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

Large scripts ship without source maps.

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

Social proof on the homepage: 1 trust badge. Pairing it with named testimonials or customer logos makes it far more convincing.

There is no form on the homepage, so every lead has to click through to another page first.

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 414 words of visible text.

Before a visitor clicks anything, the page loads Google Tag Manager (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 7 cookies, 4 of them by other companies (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.