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Lighthouse Desktop

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

Audit breakdown by category with detailed findings.

98

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.

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-0-IMG
nodeLabel: Watch calibre in action
path: 1,HTML,1,BODY,1,DIV,1,DIV,0,DIV,0,DIV,0,IMG
selector: div#content-wrapper > div#content > div#left > img
snippet: <img src="/resources/img/home-feature.jpg" alt="Watch calibre in action">

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.

URLTransfer SizeDuration
calibre-ebook.com/resources/js/jquery.tools.min.js35.3 KiB263 ms
calibre-ebook.com/resources/styles/base.css1.4 KiB
calibre-ebook.com/resources/styles/yui.css862 B
a.pub.network/calibre-ebook-com/cls.css612 B271 ms

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
a.pub.network/calibre-ebook-com/prebid.js1800.0 s183.7 KiB
www.paypalobjects.com/api/checkout.min.js3600.0 s169.3 KiB
www.paypalobjects.com/api/checkout.min.js3600.0 s169.2 KiB
a.pub.network/calibre-ebook-com/pubfig.engine.js1800.0 s140.2 KiB
cmp.inmobi.com/tcfv2/cmp2.js?referer=calibre-ebook.com3600.0 s116.4 KiB
www.paypalobjects.com/api/xo/button.js?date=2026-3-223600.0 s67.5 KiB
cmp.inmobi.com/tcfv2/61/cmp2ui-en.js172800.0 s125.3 KiB
a.pub.network/calibre-ebook-com/pubfig.min.js1800.0 s26.2 KiB
calibre-ebook.com/favicon.png?qc-size=256,2560.0 ms16.6 KiB
calibre-ebook.com/resources/js/jquery.tools.min.js604800.0 s35.3 KiB
calibre-ebook.com/resources/img/home-feature.jpg604800.0 s23.9 KiB
cmp.inmobi.com/choice/593Yp13RM2k2D/calibre-ebook.com/choice.js?tag_version=V3900.0 s2.0 KiB
/tagmanager/pptm.js?id=calibre-ebook.com&source=checkoutj...3600.0 s1.7 KiB
calibre-ebook.com/resources/img/logo.png604800.0 s13.2 KiB
calibre-ebook.com/resources/img/home-tag.png604800.0 s7.3 KiB
calibre-ebook.com/resources/img/spinner.gif604800.0 s6.8 KiB
a.pub.network/calibre-ebook-com/cls.css1800.0 s612 B
calibre-ebook.com/resources/img/button-download.png604800.0 s2.7 KiB
calibre-ebook.com/resources/img/button-getinvolved.png604800.0 s2.0 KiB
calibre-ebook.com/resources/styles/base.css604800.0 s1.4 KiB
calibre-ebook.com/resources/styles/yui.css604800.0 s862 B
calibre-ebook.com/resources/img/bg.png604800.0 s553 B
calibre-ebook.com/resources/img/blank.png604800.0 s266 B
download.calibre-ebook.com/videos/grand-tour.mp40.0 ms0 B

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
Publisher Logo div > figure > div.logo-container > img
calibre-ebook.com/favicon.png?qc-size=256,25616.5 KiB11.8 KiB

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

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 reasonFailure type
The page has an unload handler in the main frame.Actionable
The page has an unload handler in a sub frame.Actionable

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 676.0 KiB
URLTransfer SizeEst Savings
a.pub.network/calibre-ebook-com/prebid.js183.1 KiB149.7 KiB
/pagead/managed/js/gpt/m202604160201/pubads_impl.js187.7 KiB143.7 KiB
a.pub.network/calibre-ebook-com/pubfig.engine.js139.6 KiB110.9 KiB
www.googletagmanager.com/gtag/js?id=G-YMW4X5CSKP154.0 KiB77.4 KiB
cmp.inmobi.com/tcfv2/61/cmp2ui-en.js124.8 KiB59.3 KiB
cmp.inmobi.com/tcfv2/cmp2.js?referer=calibre-ebook.com115.9 KiB57.3 KiB
www.paypalobjects.com/api/checkout.min.js163.7 KiB56.2 KiB
calibre-ebook.com/resources/js/jquery.tools.min.js35.1 KiB21.4 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
Watch calibre in action div#content-wrapper > div#content > div#left > img
calibre-ebook.com/resources/img/home-feature.jpg
calibre is the one stop solution to all your e-book needs div#content-wrapper > div#content > div#right > img#one_stop
calibre-ebook.com/resources/img/home-tag.png

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

●Time to Interactive 2.4 s
●Layout shift culprits
●Document request latency
●Optimize DOM size
●Font display
●Forced reflow
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Max Potential First Input Delay 70 ms
●Minify CSS
●Minify JavaScript
●Reduce unused CSS
●Avoids enormous network payloads Total size was 1,699 KiB
●User Timing marks and measures 4 user timings
●JavaScript execution time 0.5 s
●Minimizes main-thread work 0.8 s
●Avoid long main-thread tasks 4 long tasks found
●Avoid non-composited animations 1 animated element found
●Network Requests
●Network Round Trip Times 90 ms
●Server Backend Latencies 230 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Avoid multiple page redirects
●Initial server response time was short Root document took 90 ms
●Avoid large layout shifts 1 layout shift found
○INP breakdown
100

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.

○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
●ARIA attributes are used as specified for the element's role
●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
●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 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
●No element has a `[tabindex]` value greater than 0
●Touch targets have sufficient size and spacing.
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○`[aria-hidden="true"]` elements do not contain focusable descendents
○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
○Form elements have associated labels
○Links are distinguishable without relying on color.
○The document does not use `<meta http-equiv="refresh">`
○`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
○`<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.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Identical links have the same purpose.
○Elements with visible text labels have matching accessible names.
○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.
77

Best Practices

General

Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / WarningSource
Unload event listeners are deprecated and will be removed.
www.paypalobjects.com/api/checkout.min.js line 1, col 46549
Topics
a.pub.network/calibre-ebook-com/prebid.js line 90, col 1157
Specifying overflow: visible on img, video and canvas tags may cause them to produce visual content outside of the element bounds. See https://github.com/WICG/shared-element-transitions/blob/main/debugging_overflow_on_images.md.
cmp.inmobi.com/tcfv2/61/cmp2ui-en.js line 1, col 449154

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.

SourceDescription
/tagmanager/pptm.js?client_id=AbVJy1AqjPTncpdEQteWqVN-DdU...
Failed to load resource: the server responded with a status of 410 ()
●Uses HTTPS
●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 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 clickjacking with XFO or CSP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
91

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
body > div#grid > div#donate_box > a.close body > div#grid > div#donate_box > a.close

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

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