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.

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
www.taylorfrancis.com/main.467036cc4525a890d30b.js	86392.0 s	581.6 KiB
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/tcf/ui.js	60.0 s	84.7 KiB
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/airgap.js	60.0 s	77.7 KiB
platform.twitter.com/widgets.js	1800.0 s	27.3 KiB
www.taylorfrancis.com/styles.096dfd72296b0061727a.css	86392.0 s	27.2 KiB
www.taylorfrancis.com/OpenSans-Semibold-webfont.e57adecb3a8973e1e0d7.woff?v=1	86392.0 s	23.3 KiB
www.taylorfrancis.com/OpenSans-Regular-webfont.4f6ec530947c73b0c1dd.woff?v=1	86392.0 s	23.0 KiB
www.taylorfrancis.com/OpenSans-Bold-webfont.7721ba0909593fb4c700.woff?v=1	86392.0 s	22.8 KiB
www.taylorfrancis.com/tf-icon-font.1c8aa49b38a468863785.ttf	86392.0 s	13.4 KiB
www.taylorfrancis.com/polyfills.9dd1173e3b9fbfecac89.js	86392.0 s	13.0 KiB
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/tcf/tcf.css	60.0 s	3.4 KiB
www.taylorfrancis.com/assets/images/tfgroup-logo-white.svg	86393.0 s	8.1 KiB
www.taylorfrancis.com/assets/images/ubx.svg	86393.0 s	7.5 KiB
www.taylorfrancis.com/runtime.6e966365d15ffaa0ee3d.js	86392.0 s	1.7 KiB
www.taylorfrancis.com/assets/icon/scroll-top.svg	86393.0 s	1.4 KiB

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.taylorfrancis.com/tf-icon-font.1c8aa49b38a468863785.ttf	140 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
Humanities `div.container > div.img-container > div.image-holder > img`	assets.taylorfrancis.com/wp-content/uploads/2020/08/24160803/Humanities.jpg	98.5 KiB	87.7 KiB
UBX `div.carousel-slide > a.carousel-link > div.custom-focus > img`	/wp-content/uploads/2020/08/19222049/Titile-Banner-M-comp...	77.5 KiB	31.7 KiB
Sustainable Development Goals Online `li.col-lg-4 > div.product > div.p-cover > img`	/wp-content/uploads/2020/08/29085317/ERL22DIG012-ubx-744x...	58.0 KiB	17.2 KiB
19th century British Empire `div.carousel-slide > a.carousel-link > div.custom-focus > img`	/wp-content/uploads/2020/08/01185231/GMEB24-2760-ubx-2048...	61.9 KiB	16.0 KiB
Welcome to Routledge Resources Online- The Cold War `div.carousel-slide > a.carousel-link > div.custom-focus > img`	/wp-content/uploads/2020/08/28031035/LMEB24-4005-ubx-2048...	56.4 KiB	10.6 KiB
Plant Systematics `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978100318/9781003183464.jpg	12.1 KiB	10.2 KiB
Beyond the Code `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978131564/9781315643816.jpg	11.6 KiB	9.7 KiB
Learn about Europa World `div.carousel-slide > a.carousel-link > div.custom-focus > img`	assets.taylorfrancis.com/wp-content/uploads/2020/08/04053039/EW_Cover.jpg	20.9 KiB	9.5 KiB
Archaeology and its Discontents `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978100309/9781003096115.jpg	11.3 KiB	9.5 KiB
Digital Fascism `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978100325/9781003256090.jpg	10.8 KiB	8.9 KiB
OPEN ACCESS `div.carousel-slide > a.carousel-link > div.custom-focus > img`	/wp-content/uploads/2020/08/25141758/ERL23-1850-ubx-2048x...	53.1 KiB	7.3 KiB
Big Data Applications in Industry 4.0 `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978100317/9781003175889.jpg	8.5 KiB	6.6 KiB
CRC Press `div.row > div.routledge-image > a.imprint-images > img`	assets.taylorfrancis.com/wp-content/uploads/2020/09/01105733/CRC_Press_Logo.png	6.9 KiB	6.2 KiB
Pledge to Open `div.carousel-slide > a.carousel-link > div.custom-focus > img`	/wp-content/uploads/2020/08/24130337/HEEB26-6746-ubx-mob-...	51.9 KiB	6.1 KiB
Routledge `div.row > div.routledge-image > a.imprint-images > img`	assets.taylorfrancis.com/wp-content/uploads/2020/09/01105934/Routledge_Logo.png	5.5 KiB	4.7 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-15-IMG

nodeLabel: Pledge to Open

path: 1,HTML,2,BODY,3,UBX-HOME-ROOT,0,DIV,2,MAIN,3,UBX-HOME-HOME,0,CORE-LIB-IMAGE-CAROUSAL,0,DIV,1,DIV,0,OWL-CAROUSEL-O,0,DIV,0,DIV,0,OWL-STAGE,0,DIV,0,DIV,10,DIV,0,DIV,0,A,0,DIV,0,IMG

selector: div.carousel-slide > a.carousel-link > div.custom-focus > img

snippet: <img _ngcontent-ubx-home-page-c50="" data-gtm="gtm-carousel-click" src="https://assets.taylorfrancis.com/wp-content/uploads/2020/08/24130337/HEEB2…" alt="Pledge to Open" loading="auto" style="height: 400px;">

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

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
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/airgap.js	77.7 KiB	1.4 s

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: 1.2 s

URL	Time Spent
taylorfrancis.com/	1.2 s
www.taylorfrancis.com/	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 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 25.6 KiB

URL	Transfer Size	Est Savings
www.taylorfrancis.com/styles.096dfd72296b0061727a.css	27.0 KiB	25.6 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: 1.9 s 616.8 KiB

URL	Transfer Size	Est Savings
www.taylorfrancis.com/main.467036cc4525a890d30b.js	580.7 KiB	345.0 KiB
www.googletagmanager.com/gtag/destination?id=AW-11468783382&cx=c&gtm=4e64h1	145.7 KiB	69.3 KiB
www.googletagmanager.com/gtm.js?id=GTM-5XMJVLGN&gtm=4e64h1	125.0 KiB	61.7 KiB
/gtm.js?id=GTM-NSWZ4WX&gtm_auth=RdH6vmSGiXahuYVxcLqliQ&gt...	166.2 KiB	56.8 KiB
www.googletagmanager.com/gtag/js?id=G-0HYE8YG0M6&cx=c&gtm=4e64h1	183.0 KiB	56.5 KiB
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/tcf/ui.js	84.4 KiB	27.5 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
www.taylorfrancis.com/	1.4 s	835 ms	18 ms
www.taylorfrancis.com/main.467036cc4525a890d30b.js	775 ms	486 ms	219 ms
Unattributable	716 ms	166 ms	0.0 ms
www.googletagmanager.com/gtag/js?id=G-0HYE8YG0M6&cx=c&gtm=4e64h1	580 ms	522 ms	52 ms
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/airgap.js	479 ms	404 ms	23 ms
/gtm.js?id=GTM-NSWZ4WX&gtm_auth=RdH6vmSGiXahuYVxcLqliQ&gt...	444 ms	379 ms	59 ms
www.googletagmanager.com/gtm.js?id=GTM-5XMJVLGN&gtm=4e64h1	334 ms	295 ms	31 ms
transcend-cdn.com/cm/ef49a3f1-d8c1-47d6-88fc-50e41130631f/tcf/ui.js	216 ms	176 ms	33 ms
www.googletagmanager.com/gtag/destination?id=AW-11468783382&cx=c&gtm=4e64h1	181 ms	144 ms	36 ms
www.taylorfrancis.com/polyfills.9dd1173e3b9fbfecac89.js	119 ms	104 ms	3.2 ms
platform.twitter.com/widgets.js	88 ms	61 ms	24 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
Script Evaluation	3.7 s
Other	619 ms
Script Parsing & Compilation	512 ms
Style & Layout	373 ms
Garbage Collection	113 ms
Rendering	98 ms
Parse HTML & CSS	52 ms

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 2.0 KiB

URL	Transfer Size	Est Savings
inline: ; window.NREUM \|\| (NREUM = {}); NR…	11.9 KiB	2.0 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
19th Century British Society `div.primary-product > div.row > div.col-lg-6 > img`	assets.taylorfrancis.com/wp-content/uploads/2023/06/12134145/British-society.jpg
ROUTLEDGE SUBJECT COLLECTIONS `shared-lib-general-collection.ng-star-inserted > div.featured-gac-collections > div.featured-gac-banner > img.gac-banner`	/wp-content/uploads/2020/08/24155655/General-Academic-Col...
Taylor & Francis Group Logo `div.navbar-header > core-lib-header-logo > a#gtm-header-logo > img`	www.taylorfrancis.com/assets/images/ubx.svg
Taylor & Francis Group Logo `div.logo-container > core-lib-header-logo > a#gtm-footer-logo > img`	www.taylorfrancis.com/assets/images/tfgroup-logo-white.svg

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

●Avoids enormous network payloads Total size was 2,543 KiB

●User Timing marks and measures 41 user timings

●Avoid long main-thread tasks 20 long tasks found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 50 ms

●Server Backend Latencies 430 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 270 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○Avoid non-composited animations

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.

ARIA

Some ARIA roles have required attributes that describe the state of the element to screen readers. Learn more about roles and required attributes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.hidden-lg > div > div.input-group > input#searchTerm-mobile `div.hidden-lg > div > div.input-group > input#searchTerm-mobile`

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Names and labels

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn how to make buttons more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Next `div.container > div.img-container > div.arrows > button.prev-nextBtn`

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
li > core-lib-user-menu > div > a `li > core-lib-user-menu > div > a`
core-lib-sub-header.ng-star-inserted > nav.mobilemenu > div.mobile-menu > a.dots `core-lib-sub-header.ng-star-inserted > nav.mobilemenu > div.mobile-menu > a.dots`

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.

○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]` values are valid

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

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

●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.

●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

●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

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

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

●No element has a `[tabindex]` value greater than 0

●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

●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

○Links are distinguishable without relying on color.

○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

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

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

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

○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 display dimensions should match natural aspect ratio. Learn more about image aspect ratio.

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Aspect Ratio (Displayed)	Aspect Ratio (Actual)
Humanities `div.container > div.img-container > div.image-holder > img`	assets.taylorfrancis.com/wp-content/uploads/2020/08/24160803/Humanities.jpg	150 x 145 (1.03)	722 x 756 (0.96)
Plant Systematics `div.row > div.col-md-2 > a.feat-product-ref > img.cover-images`	images.tandf.co.uk/common/jackets/crclarge/978100318/9781003183464.jpg	50 x 76 (0.66)	180 x 255 (0.71)

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

Source	Description
www.taylorfrancis.com/assets/manifest.json	`Failed to load resource: the server responded with a status of 404 ()`
www.taylorfrancis.com/	`Manifest fetch from https://www.taylorfrancis.com/assets/manifest.json failed, code 404`

Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
www.taylorfrancis.com/main.467036cc4525a890d30b.js

●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

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

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

●Ensure CSP is effective against XSS attacks

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

○Use a strong HSTS policy

○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.

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
View More `ubx-home-discover-products.ng-star-inserted > div.discover-products-container > div.view-more-container > a.ng-star-inserted`

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`