Lighthouse Desktop

· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
www.gsk.com/nuxtassets/fonts/icons.woff?e79pko	230 ms

A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Top function call valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:3.07 source:map[column:7928 line:1 type:source-location url:https://www.gsk.com/_nuxt/BQU67Am4.js urlProvider:network]]]

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:12.096 source:map[column:5272 line:0 type:source-location url:https://www.gsk.com/_nuxt/BQU67Am4.js urlProvider:network]] map[reflowTime:5.65 source:map[column:11165 line:0 type:source-location url:https://www.gsk.com/_nuxt/BQU67Am4.js urlProvider:network]] map[reflowTime:0.943 source:map[column:574 line:0 type:source-location url:https://www.gsk.com/_nuxt/BqecXCzj.js urlProvider:network]] map[reflowTime:12.729 source:map[column:1371 line:0 type:source-location url:https://www.gsk.com/_nuxt/DZbqBako.js urlProvider:network]] map[reflowTime:1.568 source:map[column:51432 line:0 type:source-location url:https://www.gsk.com/_nuxt/BQU67Am4.js urlProvider:network]] map[reflowTime:0.244 source:map[column:4855 line:0 type:source-location url:https://www.gsk.com/_nuxt/mTP6XGUH.js urlProvider:network]]]

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

value: No additional origins are good candidates for preconnecting

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
tags.tiqcdn.com/utag/gsk/profile-rx-gb/prod/utag.js	300.0 s	446.8 KiB
/media/ecyh5hhh/be-yourself.jpg?width=640&height=512&form...	604800.0 s	176.8 KiB
/media/le2hcwqq/01_viiv_zim_zvandri_high_res-75.png?width...	604800.0 s	155.9 KiB
/media/41gko4fi/img_7357-1-1.png?width=300&height=375&for...	604800.0 s	137.0 KiB
/media/402poet1/do-you-best-work.jpg?width=640&height=512...	604800.0 s	123.6 KiB
/media/hsvd0wpk/make-a-difference.jpg?width=640&height=51...	604800.0 s	110.8 KiB
/media/1z2p5lsy/tony-hero.png?rxy=0.4164980085996022,0.28...	604800.0 s	78.1 KiB
/media/hi0l5coq/viiv_nairobi029_24938.jpg?width=300&heigh...	604800.0 s	68.2 KiB
/media/zifco4go/img_6141.jpeg?width=300&height=375&format...	604800.0 s	48.0 KiB
/media/3hzkli1f/adobestock_227664167.jpeg?width=300&heigh...	604800.0 s	45.3 KiB
/utag/gsk/profile-rx-gb/prod/utag.v.js?a=gsk/profile-rx-g...	300.0 s	441 B
/media/0jwou3xu/gsk-logo.png?width=104&format=webp&qualit...	604800.0 s	1.5 KiB

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Resource Size	Est Savings
GSK Homepage `header > div.site-header-desktop > div.site-header-desktop__gsk-logo > a.site-header-desktop__gsk-logo-link`	www.gsk.com/nuxtassets/images/gif_logo_opt.gif	338.7 KiB	206.6 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/le2hcwqq/01_viiv_zim_zvandri_high_res-75.png?width...	155.8 KiB	137.5 KiB
Be yourself `div.culture__item-img > div.image > picture > img`	/media/ecyh5hhh/be-yourself.jpg?width=640&height=512&form...	176.7 KiB	123.4 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/41gko4fi/img_7357-1-1.png?width=300&height=375&for...	137.0 KiB	118.7 KiB
women walking with a laptop in her hand `div.culture__item-img > div.image > picture > img`	/media/402poet1/do-you-best-work.jpg?width=640&height=512...	123.5 KiB	70.2 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/1z2p5lsy/tony-hero.png?rxy=0.4164980085996022,0.28...	78.0 KiB	59.7 KiB
man standing and facing the camera `div.culture__item-img > div.image > picture > img`	/media/hsvd0wpk/make-a-difference.jpg?width=640&height=51...	110.7 KiB	57.4 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/hi0l5coq/viiv_nairobi029_24938.jpg?width=300&heigh...	68.1 KiB	49.8 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/zifco4go/img_6141.jpeg?width=300&height=375&format...	47.9 KiB	29.6 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/3hzkli1f/adobestock_227664167.jpeg?width=300&heigh...	45.2 KiB	26.9 KiB
GSK dark mode static background `div#main-content > main > div.culture > img`	www.gsk.com/nuxtassets/img/bg_gsk.png	240.4 KiB	22.0 KiB

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
www.gsk.com/_nuxt/entry.DFP45Lr9.css	3.8 KiB
www.gsk.com/nuxtassets/fonts/fonts.css	352 B
www.gsk.com/_nuxt/swiper.CKPHODKt.css	1.3 KiB

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 806 ms

URL	Time Spent
gsk.com/	394 ms
gsk.com/en-gb/	412 ms
www.gsk.com/en-gb/	0.0 ms

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Diagnostics

Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
Internal error.	Not actionable

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 31.9 KiB

URL	Transfer Size	Est Savings
@charset "UTF-8";:root{--gsk-orange:#f36633;--sans-serif-bold:"GSK bold",arial,helvetica,sans-serif; … } …	21.1 KiB	19.1 KiB
:root{--gsk-orange:#f36633;--sans-serif-bold:"GSK bold",arial,helvetica,sans-serif; … } …	13.8 KiB	12.8 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 247.0 KiB

URL	Transfer Size	Est Savings
tags.tiqcdn.com/utag/gsk/profile-rx-gb/prod/utag.js	445.1 KiB	150.7 KiB
www.googletagmanager.com/gtag/js	84.6 KiB	54.2 KiB
www.gsk.com/_nuxt/BQyzoT6n.js	103.7 KiB	42.2 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
www.gsk.com/media/t53gemap/antibody-drug-conjugate-animation-5x4.mp4	9.3 MiB
/media/j5lfzjwz/respiratory-syncytial-virus-rsv-science-a...	4.7 MiB
tags.tiqcdn.com/utag/gsk/profile-rx-gb/prod/utag.js	446.8 KiB
www.gsk.com/nuxtassets/images/gif_logo_opt.gif	338.8 KiB
www.gsk.com/nuxtassets/img/bg_gsk.png	240.5 KiB
/media/ecyh5hhh/be-yourself.jpg?width=640&height=512&form...	176.8 KiB
/media/le2hcwqq/01_viiv_zim_zvandri_high_res-75.png?width...	155.9 KiB
/media/41gko4fi/img_7357-1-1.png?width=300&height=375&for...	137.0 KiB
/media/402poet1/do-you-best-work.jpg?width=640&height=512...	123.6 KiB
www.gsk.com/en-gb/	112.0 KiB

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Layout shift culprits

●Optimize DOM size

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●JavaScript execution time 0.6 s

●Minimizes main-thread work 1.7 s

●Avoid long main-thread tasks 3 long tasks found

●Avoid non-composited animations 5 animated elements found

●Image elements have explicit `width` and `height`

●Network Requests

●Network Round Trip Times 40 ms

●Server Backend Latencies 210 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 180 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○LCP request discovery

○User Timing marks and measures

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Global `div.site-header-desktop > nav.top-bar > ul.top-bar__list > li.top-bar__item-location--global`
Read our magazine `div.magazine-article-carousel > div.magazine-article-carousel__panel > div.magazine-article-carousel__foot > a.button`
Careers at GSK `div.culture > div.culture__panel > div.culture__foot > a.button`
Global health and health security `div.nav > ul > li > button.btn-no-style`
Environment `div.nav > ul > li > button.btn-no-style`
Inclusion `div.nav > ul > li > button.btn-no-style`
Ethical standards `div.nav > ul > li > button.btn-no-style`
Product governance `div.nav > ul > li > button.btn-no-style`

These are opportunities to improve the legibility of your content.

Names and labels

Labels ensure that form controls are announced properly by assistive technologies, like screen readers. Learn more about form element labels.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
details.cookie_description__container_analytics > summary > label.cookie_banner_checkbox_analytics > input#toggle_cat1 `details.cookie_description__container_analytics > summary > label.cookie_banner_checkbox_analytics > input#toggle_cat1`
details.cookie_description__container_analytics > summary > label.cookie_banner_checkbox_analytics > input#toggle_cat3 `details.cookie_description__container_analytics > summary > label.cookie_banner_checkbox_analytics > input#toggle_cat3`

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Navigation

A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more about the `tabindex` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
We use cookies `body.light-theme > div#__tealiumGDPRcpPrefs > div#privacy_prompt > div.privacy_prompt_title_analytics`
GSK values your privacy and your trust is important to us. We use cookies to en… `div#privacy_prompt > div.privacy_prompt_content_analytics > p > span`
Cookie Policy `div#privacy_prompt > div.privacy_prompt_content_analytics > p > a.privacy_policy_url_analytics`
Always active Strictly Necessary Cookies ❮ Necessary for the website to functi… `div#__tealiumGDPRcpPrefs > div#privacy_prompt > div.privacy_prompt_content_analytics > div#show_more_description`
Always active Strictly Necessary Cookies ❮ Necessary for the website to functi… `div#show_more_description > ul.cookie_description_analytics > li > details.cookie_description__container_analytics`
Strictly Necessary Cookies `li > details.cookie_description__container_analytics > summary > span.cookie_description__title_analytics`
Necessary for the website to function appropriately, such as store session data… `ul.cookie_description_analytics > li > details.cookie_description__container_analytics > p.cookie_description_paragraph_analytics`
Performance cookies ❮ `div#show_more_description > ul.cookie_description_analytics > li > details.cookie_description__container_analytics`
Performance cookies `li > details.cookie_description__container_analytics > summary > span.cookie_description__title_analytics`
Advertising Cookies ❮ `div#show_more_description > ul.cookie_description_analytics > li > details.cookie_description__container_analytics`
Advertising Cookies `li > details.cookie_description__container_analytics > summary > span.cookie_description__title_analytics`
CUSTOMIZE `div#privacy_prompt > div.privacy_prompt_footer_analytics > div.prompt_button_analytics > button#preferences_prompt_customize`
ACCEPT ALL `div#privacy_prompt > div.privacy_prompt_footer_analytics > div.prompt_button_analytics > button#preferences_prompt_submit`

These are opportunities to improve keyboard navigation in your application.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●ARIA attributes are used as specified for the element's role

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●Links have a discernible name

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●Touch targets have sufficient size and spacing.

●Heading elements appear in a sequentially-descending order

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●`<video>` elements contain a `<track>` element with `[kind="captions"]`

●Uses ARIA roles only on compatible elements

●Elements with visible text labels have matching accessible names.

○`[accesskey]` values are unique

○`button`, `link`, and `menuitem` elements have accessible names

○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

○`[role]`s are contained by their required parent element

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○Image elements do not have `[alt]` attributes that are redundant text.

○Identical links have the same purpose.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

User Experience

Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Displayed size	Actual size	Expected size
Hide cookie banner `div.preferences_prompt_control_analytics > div.configuration_icon_analytics > div#configuration_icon_selected > img`		12 x 12	10 x 10	12 x 12

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Page has the HTML doctype

●Properly defines charset

●No browser errors logged to the console

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

Content Best Practices

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Link destination	Link Text
www.gsk.com/en-gb/digital-sustainability/#	More info

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`