Lighthouse Mobile

· 0 checks — Mobile 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	560 ms

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 `div.site-header-mobile > div.site-header-mobile__inner > div.site-header-mobile__gsk-logo > a.site-header-mobile__gsk-logo-link`	www.gsk.com/nuxtassets/images/gif_logo_opt.gif	338.7 KiB	206.6 KiB
GSK dark mode static background `div#main-content > main > div.culture > img`	www.gsk.com/nuxtassets/img/bg_gsk.png	240.4 KiB	160.9 KiB
Be yourself `div.culture__item-img > div.image > picture > img`	/media/ecyh5hhh/be-yourself.jpg?width=640&height=512&form...	176.7 KiB	142.6 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
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	89.4 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	76.6 KiB
div.swiper-slide > a > div.magazine-article-carousel__item-img > img `div.swiper-slide > a > div.magazine-article-carousel__item-img > img`	/media/1z2p5lsy/tony-hero.png?rxy=0.4164980085996022,0.28...	78.0 KiB	59.7 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

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-11-DIV

nodeLabel: 0:08

path: 1,HTML,2,BODY,0,DIV,39,DIV,2,DIV,0,MAIN,15,DIV,1,DIV,0,DIV,1,DIV,0,DIV,1,DIV

selector: div.hero--v2 > div.hero__body > div.hero__body-body > div.hero__media--with-twist

snippet: <div class="hero__media--with-twist hero__media">

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

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	Duration
www.gsk.com/_nuxt/swiper.CKPHODKt.css	1.3 KiB
www.gsk.com/_nuxt/entry.DFP45Lr9.css	3.8 KiB	971 ms
www.gsk.com/nuxtassets/fonts/fonts.css	346 B

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	137.1 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	438 B
/media/0jwou3xu/gsk-logo.png?width=104&format=webp&qualit...	604800.0 s	1.5 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: 2.4 s

URL	Time Spent
gsk.com/	1.1 s
gsk.com/en-gb/	1.3 s
www.gsk.com/en-gb/	0.0 ms

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.

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

Diagnostics

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: 670 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	54.1 KiB
www.gsk.com/_nuxt/BQyzoT6n.js	103.7 KiB	42.2 KiB

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Total CPU Time	Script Evaluation	Script Parse
Unattributable	2.3 s	163 ms	0.0 ms
tags.tiqcdn.com/utag/gsk/profile-rx-gb/prod/utag.js	1.7 s	1.3 s	314 ms
www.gsk.com/en-gb/	1.5 s	118 ms	2.6 ms
www.gsk.com/_nuxt/BQyzoT6n.js	476 ms	421 ms	2.2 ms
www.gsk.com/_nuxt/DDlvirwQ.js	241 ms	20 ms	0.6 ms
www.gsk.com/_nuxt/D5-xqjRT.js	232 ms	217 ms	1.4 ms
www.googletagmanager.com/gtag/js	119 ms	81 ms	36 ms
www.gsk.com/_nuxt/BQU67Am4.js	73 ms	11 ms	0.5 ms

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work

Why this matters

Performance issues directly impact user engagement and conversion rates.

Category	Time Spent
Other	2.8 s
Script Evaluation	2.4 s
Style & Layout	841 ms
Script Parsing & Compilation	363 ms
Rendering	349 ms
Parse HTML & CSS	163 ms
Garbage Collection	40 ms

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 33.0 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	19.3 KiB
:root{--gsk-orange:#f36633;--sans-serif-bold:"GSK bold",arial,helvetica,sans-serif; … } …	13.8 KiB	13.7 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...	137.1 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

●Forced reflow

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoid long main-thread tasks 11 long tasks found

●Avoid non-composited animations 5 animated elements found

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

●Network Requests

●Network Round Trip Times 0 ms

●Server Backend Latencies 520 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 200 ms

○INP breakdown

○User Timing marks and measures

○Avoid large layout shifts

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
Read the article `div.hero__head-body > div.hero__head-content > div.hero__head-body-foot > a.button`
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`

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`

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Change location `div.site-header-mobile > div.site-header-mobile__inner > div.site-header-mobile__links > a.site-header-mobile__link`

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.

●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	18 x 18

●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
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`