vsl3.com website review

About 1.0 MB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 3.8 s faster on a phone.

18 files are served with short cache lifetimes, so returning visitors download them again (388 KiB).

Your mobile performance score is 32. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 6.1 s on main-thread work while loading, 3.3 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

8 third-party services load with your homepage (Google Tag Manager, alia-prod.com and Klaviyo and others), adding 2.8 MB and 2.3 s of main-thread time.

Google Tag Manager costs a phone 881 ms of main-thread work and 1.1 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.

About 84 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 450 ms faster on a phone.

alia-prod.com costs a phone 451 ms of main-thread work and 335 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 52 KiB JavaScript that modern phones do not need. Google estimates it would make the page about 300 ms faster on a phone.

Klaviyo costs a phone 262 ms of main-thread work and 522 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.

1 image could be 5 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.

rechargecdn.com costs a phone 154 ms of main-thread work and 297 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.

Shopify costs a phone 93 ms of main-thread work and 387 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.

6 files block the first paint until they finish downloading. Deferring or inlining them could save about 250 ms.

20 long tasks block the main thread while loading, the longest for 205 ms. During a long task the page ignores taps.

38 KiB could be saved by minifying CSS.

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

6 KiB JavaScript is shipped twice across bundles.

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 JavaScript.

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

The page becomes fully interactive after 26.7 s. Good is under 3.8 s.

Visually, the page fills in at 11.9 s (Speed Index). Good is under 3.4 s.

The first text or image appears after 5.2 s on a phone. Good is under 1.8 s.

Scripts block taps and scrolling for 893 ms in total while the page loads. Good is under 200 ms.

Real visitors wait 3.0 s for the largest content to appear (75th percentile). Good is under 2.5 s.

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

Real visitors wait 1.1 s for your server to start answering (75th percentile). Good is under 800 ms.

The layout shifts by 0.123 while loading, so content jumps under the reader's thumb. Good is under 0.1.

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 153 ms to 148 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 2.7 s to 2.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 4.7 MB in 427 requests on a phone: scripts 2.8 MB (118), other files 1.2 MB (249) and images 379 KiB (27). Under 2 MB keeps phones on slow connections fast.

By the Sustainable Web Design model, a visit to your homepage emits about 1.33 g of CO₂e: 159.7 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

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

Some lists contain elements other than list items, which screen readers announce wrongly.

All page content should be contained by landmarks: 10 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.

Elements use prohibited ARIA attributes (1 element).

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

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

ARIA role should be appropriate for the element: 8 elements on the page fail this check, rated minor by axe-core.

There is no <h1>, so neither visitors nor Google get a clear main headline.

Your title is only 14 characters: “VSL Probiotics”. Between 30 and 65 characters leaves room to say what you do and for whom.

Your meta description is 188 characters; Google truncates after about 160, so the end of your pitch is cut.

The homepage links to 45 pages on vsl3.com and 2 external pages.

Your homepage links to https://www.vsl3.com/pages/the-vsl-3-difference, which answers with an error. Visitors hit a dead end and search engines drop it.

https://www.vsl3.com/collections/vsl-collection and https://www.vsl3.com/collections/vsl-3-collection are marked noindex but linked from your homepage. If they are meant to be found, remove the noindex.

https://www.vsl3.com/pages/subscribe-and-save, https://www.vsl3.com/pages/for-health-care-providers, https://www.vsl3.com/pages/fsa and https://www.vsl3.com/pages/where-to-buy have no meta description, so Google writes the search snippet from whatever text it finds.

https://www.vsl3.com/pages/subscribe-and-save, https://www.vsl3.com/pages/for-health-care-providers, https://www.vsl3.com/pages/fsa and https://www.vsl3.com/pages/contact have no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 20 found) and read each the way a search engine does.

The page uses 1 deprecated browser API that will stop working in future browsers (“Synchronous `XMLHttpRequest` on the main thread is deprecated because of its detrimental effects to…”).

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

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.

Social proof on the homepage: 6 testimonial or review blocks. Pairing it with named testimonials or customer logos makes it far more convincing.

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

The homepage has only about 55 words of visible text; thin pages give Google and first-time buyers little to go on.

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.

Before a visitor clicks anything, the page loads Google Tag Manager, Klaviyo, Meta Pixel, Microsoft Ads and Reddit Pixel (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 11 cookies, 7 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 22 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.