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 forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:104.304 source:map[type:text value:[unattributed]]]]

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-DIV

nodeLabel: REGISTER TODAY On Now: NYPL's World Literature & Arts Festival Celebrate the c…

path: 1,HTML,1,BODY,3,DIV,0,DIV,0,DIV,0,MAIN,0,DIV,0,DIV

selector: div.scout__homepage > main#mainContent > div#content-header > div.css-1kk6jc9

snippet: <div class="css-1kk6jc9">

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
cdn-d8.nypl.org/s3fs-public/2020-05/NYPL_MainFacadeRev2Cam2.png	0.0 ms	150.0 KiB
assets.nypl.org/js/advocacy.js	300.0 s	1.1 KiB

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
Large amount of books sprawled across a red table. `div#card-image-d0bc1d2d-c8e0-4e21-955b-403875565c86 > a#card-image-link-d0bc1d2d-c8e0-4e21-955b-403875565c86 > div#nextjsImage-card-image-84bcafa5-af9e-4a64-b266-719c559ec44a > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	161.8 KiB	151.1 KiB
Lion statue in front of the Stephen A. Schwarzman Building with two red banners… `div#card-image-c2e2c0b4-c8de-49ae-9f60-30407217c662 > a#card-image-link-c2e2c0b4-c8de-49ae-9f60-30407217c662 > div#nextjsImage-card-image-c72959ec-5280-48af-86ce-2c092a046c39 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	109.6 KiB	98.9 KiB
Librarian in a black dress reads a colorful picture book to a group of children… `div#card-image-257e6845-aafd-4888-8338-bd20438e51e9 > a#card-image-link-257e6845-aafd-4888-8338-bd20438e51e9 > div#nextjsImage-card-image-a134c858-8cf7-4a46-8f98-e35b741b7a8d > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	87.7 KiB	77.0 KiB
4 side-by-side headshots: Edwin Santana, Dr. Shana Russell, Tamara Santibañez, … `div.css-ys3583 > a#event-card-image-link-0e711f69-5e47-44f7-98e4-6ed166b099fe > div#nextjsImage-event-image-0e711f69-5e47-44f7-98e4-6ed166b099fe-68764dbc-1483-4173-b0bc-041d459cda01 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	67.7 KiB	66.3 KiB
Author headshots on either side of Umrigar's book, "Missing Sam." `div.css-ys3583 > a#event-card-image-link-featured-dee218d6-1ec2-4edd-8520-8a412af1d4b1 > div#nextjsImage-event-image-featured-dee218d6-1ec2-4edd-8520-8a412af1d4b1-df723cbb-51dc-4781-bf35-ef753638ca3c > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	91.2 KiB	65.8 KiB
Headshots of Bethany Crystal, Saadiq Rodgers-King, and Peta-Gay Clarke alongsid… `div.css-ys3583 > a#event-card-image-link-ae5a83b8-a5e3-43e7-ac46-c6a3227eebb4 > div#nextjsImage-event-image-ae5a83b8-a5e3-43e7-ac46-c6a3227eebb4-276eca99-6478-4c6e-9c52-44b7123f9598 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	62.2 KiB	60.9 KiB
A man and a young girl read from a book in braille while sitting at a colorful … `div#card-image-2d5a16e8-04cc-4477-b322-25367b2d8e7e > a#card-image-link-2d5a16e8-04cc-4477-b322-25367b2d8e7e > div#nextjsImage-card-image-4727dc8c-1140-4ce1-8c8b-16f396e53b84 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	69.0 KiB	59.2 KiB
2 side-by-side headshots: Lloyd Blankfein, Hortense le Gentil `div.css-ys3583 > a#event-card-image-link-fe513ce0-e808-4d00-95e3-088bc9e91ac1 > div#nextjsImage-event-image-fe513ce0-e808-4d00-95e3-088bc9e91ac1-5a2b9b13-e969-43c5-94d5-9dd45831e5f0 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	58.3 KiB	57.1 KiB
Stack of books on a wooden desk, with bookshelves in the background. `div#card-image-340f7a72-51f0-4f27-b740-11c535f337d7 > a#card-image-link-340f7a72-51f0-4f27-b740-11c535f337d7 > div#nextjsImage-card-image-9f684063-4524-47b2-ad66-391fcf663520 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	63.2 KiB	54.2 KiB
Woman holding iPad in library setting. `div#card-image-9b700650-d2f3-47d8-a2ce-35ef29ab5fcc > a#card-image-link-9b700650-d2f3-47d8-a2ce-35ef29ab5fcc > div#nextjsImage-card-image-05d4e2ed-034e-4236-a894-0dea2079ea6f > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	61.9 KiB	53.0 KiB
A woman with glasses and a scarf behind a librarian's desk hands a book to a pa… `div#card-image-af552fd5-be7f-4b69-93a6-6946b918a54e > a#card-image-link-af552fd5-be7f-4b69-93a6-6946b918a54e > div#nextjsImage-card-image-450862c7-9099-4ed3-adb5-4d67e7a768e6 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	57.5 KiB	49.3 KiB
In the foreground a stack of old books partially obscures three people research… `div#card-image-9d8525ca-1d2e-404a-b524-b7f39cea9bf2 > a#card-image-link-9d8525ca-1d2e-404a-b524-b7f39cea9bf2 > div#nextjsImage-card-image-8054cb29-7544-4a4c-9d56-26c1b9b49184 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	54.7 KiB	46.9 KiB
Two kids at a desk with notebooks open and pens in hand. `div#card-image-67214b72-ed49-4011-8a69-ddecc8611e2f > a#card-image-link-67214b72-ed49-4011-8a69-ddecc8611e2f > div#nextjsImage-card-image-4361a84b-b3ed-40e2-9072-526cf2c21e65 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	54.5 KiB	46.7 KiB
Colorful graphic featuring the word Welcome in many languages, including Englis… `div#card-image-e4e245e8-1172-4a1f-96c7-e89b8be756ac > a#card-image-link-e4e245e8-1172-4a1f-96c7-e89b8be756ac > div#nextjsImage-card-image-bde3b5bb-a710-4f20-8367-df6569a478d2 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	53.4 KiB	45.7 KiB
Messy pile of NYPL cards with one standing up and in focus in the middle of the… `div#card-image-1c1ee9c8-8d91-42b4-b596-249b294c4745 > a#card-image-link-1c1ee9c8-8d91-42b4-b596-249b294c4745 > div#nextjsImage-card-image-7f6785ad-20ac-44d2-b643-9acae9d0dd9c > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	48.3 KiB	41.4 KiB
White text reads "Get Lit!" next to the cover of the book "Lake Effect." `div#card-image-28f4c815-e5be-41bf-bfeb-2249823995cb > a#card-image-link-28f4c815-e5be-41bf-bfeb-2249823995cb > div#nextjsImage-card-image-3473f0d4-1336-469c-a148-64d7eba838c1 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	39.9 KiB	34.2 KiB
Schomburg Centennial '100' logo in red, green, and purple on a black background. `div#card-image-9ab2eaa2-866d-42f6-ad35-ffc07058e842 > a#card-image-link-9ab2eaa2-866d-42f6-ad35-ffc07058e842 > div#nextjsImage-card-image-2b037ca0-fa65-4f78-bc39-086759840a14 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	30.6 KiB	26.3 KiB
Teal text-based graphic reads: National Poetry Month, The New York Public Libra… `div#card-image-49fb4a50-c79a-4daf-9c0e-c12a7e23b10e > a#card-image-link-49fb4a50-c79a-4daf-9c0e-c12a7e23b10e > div#nextjsImage-card-image-aaff1550-a208-4b5b-8cdb-780af93393bb > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	21.8 KiB	18.7 KiB
painting the cosmos `a#staff-pick-card-link-7e0057e5-9e4c-4d6c-a167-073b9138950f > div.css-13k02e6 > div#nextjsImage-3234a3dc-7192-45cf-a121-c99a14a8fd1a > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	26.5 KiB	17.1 KiB
Haven by Ani Katz `div.css-ys3583 > a#slideshow-card-image-link-120a4b57-5c4f-45ee-8bf8-33a880606f90 > div#nextjsImage-slideshow-a0e3e293-88ec-4e7b-a6dc-09d63379ea96 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	32.7 KiB	15.7 KiB
Dark blue rectangle with gold and white Treasures exhibition logo in the center. `div#card-image-ab52dbbd-b47f-4988-a9a9-393afbf39def > a#card-image-link-ab52dbbd-b47f-4988-a9a9-393afbf39def > div#nextjsImage-card-image-c2eac3ca-8a4e-4d1d-9c7a-e68fae1d9528 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	17.8 KiB	15.3 KiB
Metropolitans: New York Baseball, Class Struggle, and the People's Team `div.css-ys3583 > a#slideshow-card-image-link-44d78fe7-4008-41e8-9a1d-1e2809e62aa5 > div#nextjsImage-slideshow-4b5aefec-07d2-43bd-b4f4-2d5502ccb326 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	31.9 KiB	14.6 KiB
Teal text-based graphic reads: Arab American Heritage Month. `div#card-image-65883ef2-2354-4365-92e4-13584c4c8cea > a#card-image-link-65883ef2-2354-4365-92e4-13584c4c8cea > div#nextjsImage-card-image-0405d297-1e6b-4ee3-9cf2-ab51e5ca565f > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	14.7 KiB	12.6 KiB
the black hunger `a#staff-pick-card-link-a63a4bf1-5f5c-44b6-9f7a-deb982807923 > div.css-13k02e6 > div#nextjsImage-7d3d690d-2bab-4e95-867c-133f24fd4df0 > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	29.2 KiB	11.9 KiB
Days of Love and Rage: A Story of Ordinary People Forging a Revolution `div.css-ys3583 > a#slideshow-card-image-link-c67f573b-8007-4536-b79f-fd06bf2b6abe > div#nextjsImage-slideshow-ef5e6951-1d89-4887-a8bd-18b8bc5fbfdc > img`	/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	28.8 KiB	11.7 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: 1.0 s

URL	Time Spent
nypl.org/	229 ms
www.nypl.org/	801 ms
www.nypl.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

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

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
a.optmnstr.com/app/js/25.7ea6f63f.min.js	468 ms	446 ms	0.1 ms
www.nypl.org/scout/_next/static/chunks/framework-3bc9684f49160ebb.js	436 ms	394 ms	10 ms
www.nypl.org/	413 ms	11 ms	0.3 ms
ds-header.nypl.org/header.min.js?containerId=nypl-header	210 ms	152 ms	57 ms
Unattributable	198 ms	3.7 ms	0.0 ms
ds-header.nypl.org/footer.min.js?containerId=nypl-footer	178 ms	110 ms	57 ms
www.nypl.org/scout/_next/static/chunks/pages/index-3442857d06f9fe36.js	171 ms	170 ms	0.1 ms
www.nypl.org/scout/_next/static/chunks/pages/_app-87b548fdd4e15b52.js	156 ms	97 ms	55 ms
www.googletagmanager.com/gtm.js?id=GTM-RKWC	143 ms	121 ms	16 ms
www.googletagmanager.com/gtag/js?id=G-P03CNT7C31&cx=c&gtm=4e64h1	137 ms	114 ms	21 ms
a.optmnstr.com/app/js/27.24395f55.min.js	75 ms	75 ms	0.1 ms
/_Incapsula_Resource?SWJIYLWA=5074a744e2e3d891814e9a2dace...	65 ms	44 ms	3.1 ms
www.nypl.org/scout/_next/static/chunks/8548-197d8009f521d522.js	53 ms	1.0 ms	51 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	2.0 s
Other	367 ms
Script Parsing & Compilation	304 ms
Style & Layout	197 ms
Rendering	67 ms
Garbage Collection	52 ms
Parse HTML & CSS	31 ms

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 15.3 KiB

URL	Transfer Size	Est Savings
www.nypl.org/scout/_next/static/css/324bf731318319c7.css	15.5 KiB	15.3 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: 0.0 ms 1.9 MiB

URL	Transfer Size	Est Savings
ds-header.nypl.org/footer.min.js?containerId=nypl-footer	551.9 KiB	449.0 KiB
www.nypl.org/scout/_next/static/chunks/pages/_app-87b548fdd4e15b52.js	530.1 KiB	447.2 KiB
ds-header.nypl.org/header.min.js?containerId=nypl-header	555.9 KiB	445.2 KiB
www.nypl.org/scout/_next/static/chunks/8548-197d8009f521d522.js	572.9 KiB	397.6 KiB
www.nypl.org/scout/_next/static/chunks/fec483df-fabc1ee4c428b220.js	98.3 KiB	98.3 KiB
www.googletagmanager.com/gtm.js?id=GTM-RKWC	172.0 KiB	64.0 KiB
www.googletagmanager.com/gtag/js?id=G-P03CNT7C31&cx=c&gtm=4e64h1	171.6 KiB	53.6 KiB
www.nypl.org/scout/_next/static/chunks/framework-3bc9684f49160ebb.js	64.9 KiB	34.4 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.nypl.org/scout/_next/static/chunks/8548-197d8009f521d522.js	611.6 KiB
ds-header.nypl.org/header.min.js?containerId=nypl-header	556.5 KiB
ds-header.nypl.org/footer.min.js?containerId=nypl-footer	552.3 KiB
www.nypl.org/scout/_next/static/chunks/pages/_app-87b548fdd4e15b52.js	530.6 KiB
www.googletagmanager.com/gtm.js?id=GTM-RKWC	172.4 KiB
www.googletagmanager.com/gtag/js?id=G-P03CNT7C31&cx=c&gtm=4e64h1	171.7 KiB
/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	162.4 KiB
cdn-d8.nypl.org/s3fs-public/2020-05/NYPL_MainFacadeRev2Cam2.png	150.0 KiB
/scout/_next/image?url=https%3A%2F%2Fdrupal.nypl.org%2Fsi...	110.1 KiB
www.nypl.org/scout/_next/static/chunks/fec483df-fabc1ee4c428b220.js	98.7 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
NYPL Main Building Facade `div.css-125sda2 > div.css-0 > div.css-0 > img.css-1uyh2tv`	cdn-d8.nypl.org/s3fs-public/2020-05/NYPL_MainFacadeRev2Cam2.png

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

●LCP breakdown

●Modern HTTP

●Network dependency tree

●Render blocking requests

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●User Timing marks and measures 20 user timings

●Avoid long main-thread tasks 13 long tasks found

●Avoid non-composited animations 85 animated elements found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 560 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 380 ms

○INP breakdown

○Avoid large layout shifts

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

●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 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

●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

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

●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 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">`

○`<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.

○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
Unload event listeners are deprecated and will be removed.	/_Incapsula_Resource?SWJIYLWA=5074a744e2e3d891814e9a2dace...
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.	/_Incapsula_Resource?SWJIYLWA=5074a744e2e3d891814e9a2dace...

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.nypl.org/scout/_next/static/chunks/pages/_app-87b548fdd4e15b52.js
www.nypl.org/scout/_next/static/chunks/8548-197d8009f521d522.js
ds-header.nypl.org/header.min.js?containerId=nypl-header
ds-header.nypl.org/footer.min.js?containerId=nypl-footer

●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 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 clickjacking with XFO or CSP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

100

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.

○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

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

○Document has a valid `rel=canonical`