Skip to content
https://kew.org

Lighthouse Mobile

· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
SCORE
0
GRADE
FIX
0
REVIEW
0
PASS
0
INFO
0

Detailed Report

Audit breakdown by category with detailed findings.

60

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.

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.

RequestCache TTLTransfer Size
/sites/default/files/styles/shop_item_image_750w/public/2...300.0 s125.4 KiB
/sites/default/files/styles/highlights_module_main_image_...300.0 s81.2 KiB
/sites/default/files/styles/highlights_module_main_image_...300.0 s79.3 KiB
/sites/default/files/styles/shop_item_image_750w/public/2...300.0 s76.8 KiB
/sites/default/files/styles/shop_item_image_750w/public/2...300.0 s75.9 KiB
/sites/default/files/styles/shop_item_image_750w/public/2...300.0 s49.6 KiB
/sites/default/files/styles/read_watch_listing/public/202...300.0 s30.4 KiB
/sites/default/files/styles/read_watch_listing/public/202...300.0 s28.9 KiB
www.kew.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1209.0 s27.3 KiB
/sites/default/files/styles/highlights_module_main_image_...300.0 s26.2 KiB
/sites/default/files/css/css_OM_7jI2EYA8GXeg0nEQNZWP4pGN_...300.0 s25.8 KiB
web.cmp.usercentrics.eu/ui/TvGdprCmpView.35a2009d.js3600.0 s29.6 KiB
/sites/default/files/js/js_wIeOFjg-CzyadXkR9T7fRkwfrJTVOT...300.0 s20.0 KiB
/sites/default/files/styles/read_watch_listing/public/202...300.0 s16.0 KiB
/sites/default/files/styles/read_watch_listing/public/202...300.0 s15.3 KiB
web.cmp.usercentrics.eu/ui/loader.js3600.0 s15.2 KiB
/sites/default/files/styles/read_watch_listing/public/202...300.0 s11.5 KiB
/sites/default/files/css/css_LO_FkWUxtXwrGKesfrCSIywikhnx...300.0 s8.7 KiB
/sites/default/files/styles/read_watch_listing/public/201...300.0 s7.4 KiB
/sites/default/files/js/js_Z0dAkOWBky61naq4t0mWcPs84PU-gE...300.0 s3.4 KiB
www.kew.org/themes/custom/kew_gardens/js/src/slider.js?tdky8u300.0 s2.7 KiB
/sites/default/files/styles/section_image_mobile/public/2...300.0 s2.6 KiB
www.kew.org/themes/custom/kew_gardens/js/src/site-nav.js?tdky8u300.0 s1.9 KiB
web.cmp.usercentrics.eu/tcf/stub.js3600.0 s1.9 KiB
www.kew.org/themes/custom/kew_gardens/js/src/search.js?tdky8u209.0 s1.4 KiB
www.kew.org/themes/custom/kew_gardens/js/src/main.js?tdky8u209.0 s1.2 KiB
app.usercentrics.eu/session/1px.png?settingsId=gdkzoAfLCGpK2e1800.0 s1.0 KiB
www.kew.org/modules/contrib/google_tag/js/gtag.js?tdky8u300.0 s898 B
www.kew.org/modules/contrib/google_tag/js/gtm.js?tdky8u208.0 s822 B
www.kew.org/themes/custom/kew_gardens/assets/nav-back.svg300.0 s774 B
www.kew.org/themes/custom/kew_gardens/assets/nav-expandable.svg300.0 s764 B
www.kew.org/themes/custom/kew_gardens/assets/arrow-right.svg300.0 s684 B
/sites/default/files/js/js_JCv9eGr5Sbr8GO9o-fRgZHq_Nl4kqy...300.0 s522 B
/fire?pixelId=e855dd1a-f835-49a2-9765-9045f84091f5&type=s...0.0 ms175 B
/eu01/v.gif?cd=0&a=1061784&d=kew.org&u=DD71B48C38F75F4DA1...43200.0 s147 B

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.

URLEst Savings
fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff245 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.

URLResource SizeEst Savings
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...125.0 KiB102.5 KiB
A view of the path leading to the Temperate House with cherry blossom trees eit… div.highlights > div.highlights__content > div.highlights__image-wrapper > img
/sites/default/files/styles/highlights_module_main_image_...80.9 KiB65.4 KiB
View of the trees surrounding Wakehurst's Mansion Pond being reflected in the w… div.highlights > div.highlights__content > div.highlights__image-wrapper > img
/sites/default/files/styles/highlights_module_main_image_...79.0 KiB63.5 KiB
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...76.5 KiB57.7 KiB
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...75.6 KiB57.0 KiB
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...49.3 KiB37.2 KiB
main > div.layout-content > section.home-hero > div.home-hero__background--mobile main > div.layout-content > section.home-hero > div.home-hero__background--mobile
/sites/default/files/styles/original/public/2026-03/17051...84.7 KiB27.3 KiB
Three deep purple slipper orchids with striped petals and inflated pouches grow… div.c-card__inner > div.c-card__top > figure.c-card__image > img
/sites/default/files/styles/read_watch_listing/public/202...30.2 KiB18.8 KiB
Botanical Propagation Assistant, Eliana Van Der Schraft, is scarifying seed und… div.highlights > div.highlights__content > div.highlights__image-wrapper > img
/sites/default/files/styles/highlights_module_main_image_...26.0 KiB18.1 KiB
Full ginkgo biloba tree with yellow leaves in autumn div.c-card__inner > div.c-card__top > figure.c-card__image > img
/sites/default/files/styles/read_watch_listing/public/202...28.6 KiB17.3 KiB
Image of a cherry blossom tree on a sunny day, with the Palm House in the backg… div.c-card__inner > div.c-card__top > figure.c-card__image > img
/sites/default/files/styles/read_watch_listing/public/202...15.7 KiB4.7 KiB
Kew scientist in coat holding jar of seeds div.c-card__inner > div.c-card__top > figure.c-card__image > img
/sites/default/files/styles/read_watch_listing/public/202...15.0 KiB4.5 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-6-DIV
nodeLabel: main > div.layout-content > section.home-hero > div.home-hero__background--mobile
path: 1,HTML,1,BODY,2,DIV,0,DIV,2,MAIN,1,DIV,0,SECTION,1,DIV
selector: main > div.layout-content > section.home-hero > div.home-hero__background--mobile
snippet: <div class="home-hero__background--mobile home-hero__background-image" style="--bg-image-mobile: url('https://www.kew.org/sites/default/files/styles/ori…;">

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
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

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.

URLTransfer SizeDuration
/sites/default/files/js/js_JCv9eGr5Sbr8GO9o-fRgZHq_Nl4kqy...522 B
/sites/default/files/css/css_OM_7jI2EYA8GXeg0nEQNZWP4pGN_...25.8 KiB302 ms
/sites/default/files/css/css_LO_FkWUxtXwrGKesfrCSIywikhnx...8.7 KiB
www.kew.org/modules/contrib/google_tag/js/gtag.js?tdky8u898 B
web.cmp.usercentrics.eu/tcf/stub.js1.9 KiB802 ms
/css?family=Roboto:300,300i,400,400i,500,500i,700,700i,90...2.7 KiB831 ms
www.kew.org/modules/contrib/google_tag/js/gtm.js?tdky8u822 B

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: 850 ms
URLTime Spent
kew.org/850 ms
www.kew.org/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

Diagnostics

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: 300 ms 35.7 KiB
URLTransfer SizeEst Savings
/sites/default/files/css/css_OM_7jI2EYA8GXeg0nEQNZWP4pGN_...25.6 KiB23.3 KiB
.overlay { --color-cmp-overlay: #262626; --feature-overlay-opacity: 0.7; } …15.6 KiB12.4 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: 750 ms 102.6 KiB
URLTransfer SizeEst Savings
www.googletagmanager.com/gtm.js?id=GTM-WHZGP8176.4 KiB71.5 KiB
web.cmp.usercentrics.eu/ui/v/3.117.0/WebSdk.lib.4c6726a9.js56.0 KiB31.1 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...
li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img li.shop-listing > div.shop-listing__inner > figure.shop-listing__image > img
/sites/default/files/styles/shop_item_image_750w/public/2...

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

●Max Potential First Input Delay 130 ms
●Layout shift culprits
●Optimize DOM size
●Forced reflow
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Minify CSS
●Minify JavaScript
●Avoids enormous network payloads Total size was 1,232 KiB
●JavaScript execution time 0.6 s
●Minimizes main-thread work 1.3 s
●Avoid long main-thread tasks 6 long tasks found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 30 ms
●Server Backend Latencies 150 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 10 ms
○INP breakdown
○User Timing marks and measures
○Avoid non-composited animations
○Avoid large layout shifts
93

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.

Tables and lists

Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. Learn more about proper list structure.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Back Kew Gardens Visit Kew What’s on What’s in the Gardens Families School visi… nav#block-mainnavigation > ul.nav > li > ul.nav
Back Wakehurst Visit Wakehurst What’s on What’s in the gardens Families School … nav#block-mainnavigation > ul.nav > li > ul.nav
Back Kew Science Read & watch Our science Collections & resources Science train… nav#block-mainnavigation > ul.nav > li > ul.nav
Back Read & watch Plant profiles Virtual Kew Unearthed podcast nav#block-mainnavigation > ul.nav > li > ul.nav
Back Learning Schools at Kew Schools at Wakehurst Study with Kew Science School… nav#block-mainnavigation > ul.nav > li > ul.nav
Back Membership Become a Kew member Become a Wakehurst member Join in Kew membe… nav#block-mainnavigation > ul.nav > li > ul.nav

These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.

Best practices

Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Accessibility nav#block-footerbottom > ul > li > a

These items highlight common accessibility best practices.

○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
●Form elements have associated labels
●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
●`button`, `link`, and `menuitem` elements have accessible names
●ARIA attributes are used as specified for the element's role
●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●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
●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
●No element has a `[tabindex]` value greater than 0
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
●ARIA IDs are unique
●Uses ARIA roles only on compatible elements
●Identical links have the same purpose.
●Elements with visible text labels have matching accessible names.
○`[accesskey]` values are unique
○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
○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.
○Skip links are focusable.
○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
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○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.
○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.
100

Best Practices

●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
●Serves images with appropriate resolution
●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
92

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.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
Back ul.nav > li > ul.nav > a.nav__item
Back ul.nav > li > ul.nav > a.nav__item
Back ul.nav > li > ul.nav > a.nav__item
Back ul.nav > li > ul.nav > a.nav__item
Back ul.nav > li > ul.nav > a.nav__item
Back ul.nav > li > ul.nav > a.nav__item

To appear in search results, crawlers need access to your app.

○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 have descriptive text
●robots.txt is valid
●Image elements have `[alt]` attributes
●Document has a valid `hreflang`
●Document has a valid `rel=canonical`

Send Feedback