kosbiotic.com website review

Your mobile performance score is 63. Pages that score under 90 lose visitors before the first paint.

8 third-party services load with your homepage (Klaviyo, Shopify and openai.com and others), adding 569 KiB and 512 ms of main-thread time.

About 286 KiB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 150 ms faster on a phone.

A phone's processor spends 3.7 s on main-thread work while loading, 1.9 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

14 files are served with short cache lifetimes, so returning visitors download them again (347 KiB).

The page has 2,103 HTML elements. Above 1,500, rendering and every interaction get slower on phones.

7 long tasks block the main thread while loading, the longest for 238 ms. During a long task the page ignores taps.

2 images could be 44 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen.

40 KiB could be saved by minifying JavaScript.

Polyfills for old browsers add 19 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.

The page becomes fully interactive after 14.1 s. Good is under 3.8 s.

The first text or image appears after 4.3 s on a phone. Good is under 1.8 s.

Visually, the page fills in at 6.8 s (Speed Index). Good is under 3.4 s.

Your largest element takes 4.3 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the text “Ce site web utilise des cookies pour vous garantir une expé…”. Most of its time is element render delay (2.6 s).

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' tap response (inp) went from 144 ms to 205 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Scripts block taps and scrolling for 346 ms in total while the page loads. Good is under 200 ms.

Over the last 25 four-week periods to 2026-10-31, real Chrome visitors' largest content (lcp) went from 1.3 s to 1.6 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 2.5 MB in 276 requests on a phone: scripts 1.0 MB (87), other files 791 KiB (106) and images 373 KiB (22). Under 2 MB keeps phones on slow connections fast.

2 images (69 KiB) are 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 0.70 g of CO₂e: 83.9 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

3 text elements don't have enough contrast against the background to read easily, especially outdoors on a phone.

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

All page content should be contained by landmarks: 1 element on the page fails this check, rated moderate by axe-core.

3 form fields have no label, so screen readers announce an empty box and autofill guesses.

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

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

Your title is only 9 characters: “Kosbiotic”. Between 30 and 65 characters leaves room to say what you do and for whom.

Structured data found (ItemList, Organization and WebSite) but with 1 problem, for example “Organization: logo is not an absolute URL ("//kosbiotic.com/cdn/shop/t/37/assets/logo.svg?v=7425199…”.

The homepage links to 74 pages on kosbiotic.com and 5 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.

https://kosbiotic.com/pages/notre-philosophie, https://kosbiotic.com/blogs/journal, https://kosbiotic.com/policies/privacy-policy and https://kosbiotic.com/collections/pack-bundle use the same meta description. A description written for each page earns more clicks.

https://kosbiotic.com/pages/etudes-cliniques, https://kosbiotic.com/products/probiotiques-ventre-plat-slim-my-body, https://kosbiotic.com/products/probiotique-anti-stress-calm-my-mind, https://kosbiotic.com/products/probiotiques-flore-intestinale-digest-delight, https://kosbiotic.com/products/pack-slim-my-body-digest-delight and https://kosbiotic.com/products/pack-slim-my-body-calm-my-mind and 7 others have no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 19 found) and read each the way a search engine does.

26 of 56 tappable elements near the top of the page are smaller than 24 px, hard to hit with a thumb.

1 third-party cookie is set on load; browsers are restricting these, so whatever relies on them breaks.

4 errors were logged to the browser console while the page loaded, for example “Failed to load resource: the server responded with a status of 500 ()”.

Large scripts ship without source maps.

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

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: 2 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.

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 392 words of visible text.

Before a visitor clicks anything, the page loads Klaviyo, Meta Pixel and TikTok 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 13 cookies (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 14 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.