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.

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.delta.com/content/dam/delta-tnt/homepage/card-cd/brycecanyon-ut-slc-945.webp	0.0 ms	151.2 KiB
www.delta.com/content/dam/delta-tnt/homepage/btf/wf-3383622-01-1050x600.webp	0.0 ms	140.4 KiB
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	0.0 ms	128.6 KiB
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	0.0 ms	125.0 KiB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	21600.0 s	172.8 KiB
/content/dam/delta-com/products/delta-experiences/main-ca...	0.0 ms	91.6 KiB
/content/dam/delta-tnt/homepage/card-cd/premium-cabin-dea...	0.0 ms	73.0 KiB
/content/dam/delta-com/products/delta-experiences/delta-p...	0.0 ms	60.3 KiB
www.delta.com/content/dam/delta-tnt/homepage/btf/wf-3175001-02-1050x600.webp	0.0 ms	56.5 KiB
cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js	86400.0 s	115.9 KiB
www.delta.com/content/dam/delta-com/products/map/fda-homepage-700x425.webp	0.0 ms	39.2 KiB
www.delta.com/ruxitagentjs_ICA27NVfghjqrx_10285240307101407.js	86400.0 s	75.3 KiB
www.delta.com/content/dam/delta-tnt/homepage/covid/icon-flight-changes-1000.webp	0.0 ms	9.2 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RC955d0ae6fa194fa...	3600.0 s	4.3 KiB
/logos/6b6d972e-480d-4bb2-96d3-4bf62b3d9551/0191fd5a-9aa4...	86400.0 s	3.6 KiB
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RC6d20ec2c5bbb40d...	3600.0 s	1.5 KiB
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RC5618ada8bb5b47d...	3600.0 s	1.4 KiB
cdn.cookielaw.org/logos/static/powered_by_logo.svg	86400.0 s	2.1 KiB
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RCe7c3c47950ce471...	3600.0 s	1.0 KiB
/usage.gif?token=40c5d1df6a8049dfa571d3e4324bef72&correla...	0.0 ms	273 B
/usage.gif?token=40c5d1df6a8049dfa571d3e4324bef72&correla...	0.0 ms	273 B
cdn.cookielaw.org/logos/static/ot_close.svg	86400.0 s	643 B
www.delta.com/homepage/26.3.8/mach-core/browser/main.js	10606.0 s	0 B
www.delta.com/homepage/26.3.8/mach-core/browser/styles.css	86400.0 s	0 B
/NxvV2/ISv/V5F2/Si/veeSUD/wb7hbLaQ/K0ciPAE/UHQfJX/dcDxdt?...	21600.0 s	0 B
assets.adobedtm.com/3b29aa0834b1/0e49b4a4297a/launch-ab7c06f028a9.min.js	3600.0 s	0 B
www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e	600.0 s	0 B
s.go-mpulse.net/boomerang/PWV8J-R2M7Y-67AAN-EA9TD-6DRAX	604800.0 s	0 B
www.delta.com/content/dam/delta-tnt/homepage/card-cd/brycecanyon-ut-slc-945.webp	0.0 ms	0 B
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	0.0 ms	0 B
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	0.0 ms	0 B
/content/dam/delta-com/products/delta-experiences/main-ca...	0.0 ms	0 B
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/wb/d1V3OwE/UmB7Xj/cGAGcp	86400.0 s	0 B
p11.techlab-cdn.com/e/65226_747628124.js	600.0 s	0 B
p11.techlab-cdn.com/e/65319_1825172608.js	600.0 s	0 B
www.delta.com/content/dam/delta-tnt/homepage/btf/wf-3175001-02-1050x600.webp	0.0 ms	0 B
www.delta.com/content/dam/delta-com/products/map/fda-homepage-700x425.webp	0.0 ms	0 B
www.delta.com/homepage/26.3.8/mach-core/browser/polyfills.js	10599.0 s	0 B
www.delta.com/content/dam/delta-applications/login/assets/tracker-3.10.1.js	604800.0 s	0 B
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	0 B
p11.techlab-cdn.com/e/65257_1825202461.js	600.0 s	0 B
www.delta.com/content/dam/delta-tnt/homepage/covid/icon-flight-changes-1000.webp	0.0 ms	0 B
p11.techlab-cdn.com/e/64885_1825202492.js	600.0 s	0 B
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/wb/d1V3OwE/HyYAC1/0AVHVY	86400.0 s	0 B
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RC9c4892907897447...	3600.0 s	0 B
/3b29aa0834b1/0e49b4a4297a/e94de24008a4/RC286d4830056d424...	3600.0 s	0 B

Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]

items: [map[duration:474.892 label:Time to first byte subpart:timeToFirstByte] map[duration:-409.938 label:Resource load delay subpart:resourceLoadDelay] map[duration:364.521 label:Resource load duration subpart:resourceLoadDuration] map[duration:2328.25 label:Element render delay subpart:elementRenderDelay]]

lhId: page-0-IMG

nodeLabel: Image of seaside town

path: 1,HTML,1,BODY,2,IDP-ROOT,1,IDP-CONTENT-BODY,2,DIV,4,DIV,0,DIV,1,DIV,1,IMG

selector: div.cmp-container > div.hero > div.bg-surface-navigation > img.tablet:block

snippet: <img alt="Image of seaside town " class="tablet:block hidden h-full w-full object-cover" src="/content/dam/delta-tnt/homepage/hero/2025/Retail/current-flight-deals/wf-3…" fetchpriority="high" width="1600" height="624">

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: Image of seaside town

path: 1,HTML,1,BODY,2,IDP-ROOT,1,IDP-CONTENT-BODY,2,DIV,4,DIV,0,DIV,1,DIV,1,IMG

selector: div.cmp-container > div.hero > div.bg-surface-navigation > img.tablet:block

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.

More than 4 preconnect connections were found. These should be used sparingly and only to the most important origins.

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.

URL	Transfer Size	Duration
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	172.8 KiB	320 ms
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/wb/d1V3OwE/HyYAC1/0AVHVY	0 B
www.delta.com/homepage/26.3.8/mach-core/browser/styles.css	0 B
www.delta.com/content/dam/delta-applications/login/assets/tracker-3.10.1.js	0 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.

	URL	Resource Size	Est Savings
How Can I Change/Cancel My Flight? `div.w-full > div.image-card > div.card-image-ratio > img.card-image-content`	www.delta.com/content/dam/delta-tnt/homepage/covid/icon-flight-changes-1000.webp	8.7 KiB	5.3 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: 2.5 s

URL	Time Spent
www.delta.com/	2.5 s
www.delta.com/eu/en	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

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: 850 ms 1.3 MiB

URL	Transfer Size	Est Savings
www.delta.com/homepage/26.3.8/mach-core/browser/main.js	660.9 KiB	352.0 KiB
www.delta.com/homepage/26.3.8/mach-core/browser/main.js	660.9 KiB	342.4 KiB
/NxvV2/ISv/V5F2/Si/veeSUD/wb7hbLaQ/K0ciPAE/UHQfJX/dcDxdt?...	159.4 KiB	81.4 KiB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	171.5 KiB	67.1 KiB
cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js	115.8 KiB	61.6 KiB
tms.delta.com/delta/dl_anderson/Bootstrap.js	96.0 KiB	51.1 KiB
assets.adobedtm.com/3b29aa0834b1/0e49b4a4297a/launch-ab7c06f028a9.min.js	99.8 KiB	48.7 KiB
tms.delta.com/delta/dl_anderson/Bootstrap.js	96.0 KiB	45.1 KiB
assets.adobedtm.com/3b29aa0834b1/0e49b4a4297a/launch-ab7c06f028a9.min.js	99.8 KiB	37.2 KiB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	171.5 KiB	35.8 KiB
/NxvV2/ISv/V5F2/Si/veeSUD/wb7hbLaQ/K0ciPAE/UHQfJX/dcDxdt?...	159.4 KiB	33.6 KiB
www.delta.com/ruxitagentjs_ICA27NVfghjqrx_10285240307101407.js	74.7 KiB	33.2 KiB
s.go-mpulse.net/boomerang/PWV8J-R2M7Y-67AAN-EA9TD-6DRAX	48.6 KiB	32.7 KiB
s.go-mpulse.net/boomerang/PWV8J-R2M7Y-67AAN-EA9TD-6DRAX	48.6 KiB	29.6 KiB
www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e	61.7 KiB	23.2 KiB
/delta/dl_anderson/code/a7f0e2c2a7413c6659c51a8ec43b3e6a....	29.8 KiB	21.4 KiB
www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e	61.7 KiB	21.4 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.delta.com/homepage/26.3.8/mach-core/browser/polyfills.js	1.2 s	1.0 s	1.9 ms
www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e	1.0 s	896 ms	33 ms
Unattributable	843 ms	194 ms	0.0 ms
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	448 ms	383 ms	45 ms
/NxvV2/ISv/V5F2/Si/veeSUD/wb7hbLaQ/K0ciPAE/UHQfJX/dcDxdt?...	376 ms	290 ms	77 ms
www.delta.com/eu/en	368 ms	5.1 ms	1.7 ms
tms.delta.com/delta/dl_anderson/Bootstrap.js	346 ms	274 ms	54 ms
assets.adobedtm.com/3b29aa0834b1/0e49b4a4297a/launch-ab7c06f028a9.min.js	237 ms	172 ms	55 ms
www.delta.com/homepage/26.3.8/mach-core/browser/main.js	171 ms	3.2 ms	167 ms
cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js	136 ms	92 ms	19 ms
www.delta.com/akam/13/4addec96	72 ms	69 ms	1.6 ms
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/wb/d1V3OwE/UmB7Xj/cGAGcp	55 ms	40 ms	9.9 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	936 ms
Script Parsing & Compilation	537 ms
Style & Layout	262 ms
Parse HTML & CSS	101 ms
Garbage Collection	90 ms
Rendering	66 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
The page has an unload handler in the main frame.	Actionable
The page has an unload handler in a sub frame.	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 18.8 KiB

URL	Transfer Size	Est Savings
	21.1 KiB	18.8 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.delta.com/homepage/26.3.8/mach-core/browser/main.js	661.6 KiB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	172.9 KiB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB	172.8 KiB
/NxvV2/ISv/V5F2/Si/veeSUD/wb7hbLaQ/K0ciPAE/UHQfJX/dcDxdt?...	159.9 KiB
www.delta.com/content/dam/delta-tnt/homepage/card-cd/brycecanyon-ut-slc-945.webp	151.2 KiB
www.delta.com/content/dam/delta-tnt/homepage/btf/wf-3383622-01-1050x600.webp	140.4 KiB
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	128.6 KiB
/content/dam/delta-tnt/homepage/hero/2025/Retail/current-...	125.0 KiB
cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js	115.9 KiB
assets.adobedtm.com/3b29aa0834b1/0e49b4a4297a/launch-ab7c06f028a9.min.js	100.1 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
Refundable Only Help Icon `div.flex > div.flex > div.w-[24px] > img.grayscale-effect`	/content/dam/delta-applications/sitewide/capability/fligh...

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

●Layout shift culprits

●Document request latency

●Optimize DOM size

●Font display

●Forced reflow

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●User Timing marks and measures 82 user timings

●Avoid long main-thread tasks 20 long tasks found

●Avoid non-composited animations 1 animated element found

●Network Requests

●Network Round Trip Times 20 ms

●Server Backend Latencies 190 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 470 ms

●Avoid large layout shifts 15 layout shifts found

○INP breakdown

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

Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values. Learn more about valid values for ARIA attributes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Book `ul#mach-core-header-nav-primary-list > div.flex > li#mach-core-header-nav-primary-0 > a#headPrimary1`

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

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
div.bg-surface-navigation > div.hph-message-content > span.hph-description > a `div.bg-surface-navigation > div.hph-message-content > span.hph-description > a`

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.

Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
AMS Amsterdam, Netherlands `idp-book-widget-search-modal-mach-core > div.airport-search-modal > div#one-way-route-picker > button#one-way-route-picker-origin-button`
To Destination `idp-book-widget-search-modal-mach-core > div.airport-search-modal > div#one-way-route-picker > button#one-way-route-picker-destination-button`
Depart - Return `div.gap-8 > idp-date-picker-mach-core.laptop:w-[195.5px] > div.flex > button#date-picker-trigger-qf2ac54hdr8`
Netherlands - English `div > idp-language-selector > div#mach-homepage-footer-language-selector-container > a#mach-homepage-footer-language-selector`

○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

●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

●`[role]` values are valid

●`[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

●ARIA `tooltip` elements have accessible names

●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.

●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

●Uses ARIA roles only on compatible elements

●Identical links have the same purpose.

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

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

○ARIA toggle fields 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.

○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.

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 / Warning	Source
SharedStorage	www.delta.com/content/dam/delta-applications/login/assets/tracker-3.10.1.js line 16, col 201
Unload event listeners are deprecated and will be removed.	www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e line 141, col 127
SharedStorage	www.delta.com/content/dam/delta-applications/login/assets/tracker-3.10.1.js line 16, col 201
Unload event listeners are deprecated and will be removed.	www.delta.com/resources/df032bb95163120c0d0265eb98f27f913a30d77a1d98e line 141, col 127

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
	`A bad HTTP response code (444) was received when fetching the script.`
	`A bad HTTP response code (444) was received when fetching the script.`
www.delta.com/akam/13/4addec96	`Failed to load resource: the server responded with a status of 404 ()`
www.delta.com/eu/en line 65, col 0	`Refused to execute script from 'https://www.delta.com/akam/13/4addec96' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.`

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.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB
www.delta.com/NxvV2/ISv/V5F2/Si/veeSUD/1G7hbLaQkOX7LS/fQUZPAE/fnJiRG/IXEUIB
www.delta.com/homepage/26.3.8/mach-core/browser/main.js
www.delta.com/homepage/26.3.8/mach-core/browser/main.js

●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

○Redirects HTTP traffic to HTTPS

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
Select other Location and Language `div.pop-up-box > div.pop-up-box-content > div.flex > a.link`

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

Content Best Practices

Canonical links suggest which URL to show in search results. Learn more about canonical links.

Why this matters

Informational: a Permissions-Policy directive showing feature -> allowed origins.

Source: MDN Permissions-Policy

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 have descriptive text

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

○robots.txt is valid