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Lighthouse Mobile

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

Audit breakdown by category with detailed findings.

9

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
s.swiftypecdn.com/install/v2/st.js300.0 s111.8 KiB
i.ytimg.com/vi/wO_ecqK2ARo/sddefault.jpg7200.0 s96.3 KiB
www.acm.org/js/acm.js?antiCache=174490700593714400.0 s76.9 KiB
www.acm.org/fonts/fontawesome-webfont.woff2?v=4.3.014400.0 s55.7 KiB
consent.cookiebot.com/uc.js1040.0 s35.7 KiB
www.acm.org/css/acm.css?antiCache=174490700593714400.0 s39.4 KiB
www.acm.org/css/acm-blessed1.css?z=26214400.0 s35.2 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/awards/t...2104452.0 s136.4 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...1000691.0 s107.8 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...459684.0 s73.4 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...1578101.0 s104.7 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/r...788241.0 s97.7 KiB
www.acm.org/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/main.js?14400.0 s12.9 KiB
www.acm.org/js/analytics.js?=14400.0 s11.3 KiB
snap.licdn.com/li.lms-analytics/insight.min.js86400.0 s18.7 KiB
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/p...840477.0 s45.8 KiB
www.acm.org/js/modernizr.js14400.0 s4.8 KiB
i.ytimg.com/vi/wO_ecqK2ARo/default.jpg7200.0 s3.3 KiB
www.acm.org/css/print.css?antiCache=174490700593714400.0 s1.0 KiB
/collect?v=2&fmt=js&pid=36002&time=1776797981151&li_adsId...0.0 ms667 B
www.acm.org/js/classList.js14400.0 s951 B
www.acm.org/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js2866.0 s771 B
/consentconfig/9bb7fc8b-05a2-4292-85e6-45213b19c5ff/acm.o...38671.0 s1.1 KiB
www.acm.org/js/webfontloader.js14400.0 s626 B
www.acm.org/js/classList.js14400.0 s0 B
www.acm.org/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js2866.0 s0 B
www.acm.org/js/webfontloader.js14400.0 s0 B

Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.451671] map[node:map[boundingRect:map[bottom:9380 height:8985 left:0 right:412 top:395 width:412] lhId:page-29-DIV nodeLabel:ACM ELECTIONS Vote in the 2026 ACM General Election - Ballots Due by 22 May at … path:1,HTML,1,BODY,14,DIV,1,DIV,0,ARTICLE,0,DIV selector:div#main > div#maincontent > article#SkipTarget > div.row snippet:<div class="row"> type:node] score:0.439879 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2]]] type:subitems]] map[node:map[boundingRect:map[bottom:942 height:118 left:32 right:380 top:825 width:348] lhId:page-28-P nodeLabel:On 16 April, ACM Professional Members in good standing as of 1 April 2026 were … path:1,HTML,1,BODY,14,DIV,1,DIV,0,ARTICLE,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV,2,DIV,1,P selector:div.medium-8 > div.text-wrap > div.dek > p snippet:<p> type:node] score:0.011773 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:80 height:80 left:0 right:105 top:0 width:105] lhId:page-31-IMG nodeLabel:ACM Logo path:1,HTML,1,BODY,13,DIV,1,DIV,0,DIV,1,DIV,0,A,0,IMG selector:div.logo-section > div.navbar-header > a.js-no-link-icon > img.img-responsive snippet:<img alt="ACM Logo" class="img-responsive hide-for-large-up" src="/binaries/content/gallery/global/top-menu/acm_logo_mobile.svg"> type:node]]] type:subitems]] map[score:1.9e-05]]

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
/s/robotocondensed/v31/ieVl2ZhZI2eCN5jzbjEETS9weq8-19K7DQ...60 ms
/s/robotocondensed/v31/ieVl2ZhZI2eCN5jzbjEETS9weq8-19K7DQ...50 ms
/s/robotocondensed/v31/ieVj2ZhZI2eCN5jzbjEETS9weq8-19eLDw...50 ms
/s/robotocondensed/v31/ieVj2ZhZI2eCN5jzbjEETS9weq8-19eLDw...50 ms
www.acm.org/fonts/fontawesome-webfont.woff2?v=4.3.045 ms
fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff245 ms
fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff240 ms
/s/robotocondensed/v31/ieVj2ZhZI2eCN5jzbjEETS9weq8-19eLDw...25 ms
cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/fonts/slick.woff25 ms
fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff220 ms
/s/robotocondensed/v31/ieVl2ZhZI2eCN5jzbjEETS9weq8-19K7DQ...15 ms

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:Top function call valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:0.736 source:map[column:4074 line:74 type:source-location url:https://s.swiftypecdn.com/install/v2/st.js urlProvider:network]]]
headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:208.971 source:map[type:text value:[unattributed]]] map[reflowTime:0.817 source:map[column:1519 line:0 type:source-location url:https://www.acm.org/cdn-cgi/challenge-platform/scripts/jsd/main.js urlProvider:network]] map[reflowTime:0.333 source:map[column:10068 line:24 type:source-location url:https://s.swiftypecdn.com/install/v2/st.js urlProvider:network]] map[reflowTime:0.218 source:map[column:10126 line:24 type:source-location url:https://s.swiftypecdn.com/install/v2/st.js urlProvider:network]] map[reflowTime:0.185 source:map[column:10190 line:24 type:source-location url:https://s.swiftypecdn.com/install/v2/st.js urlProvider:network]] map[reflowTime:13.014 source:map[column:31671 line:24 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:10.116 source:map[column:5009 line:25 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:0.642 source:map[column:14340 line:24 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:5.719 source:map[column:3948 line:13 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:35.09 source:map[column:2979 line:13 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:43.975 source:map[column:3934 line:13 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:0.25 source:map[column:12691 line:24 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]] map[reflowTime:3.915 source:map[column:3001 line:13 type:source-location url:https://www.acm.org/js/acm.js?antiCache=1744907005937 urlProvider:network]]]

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
A New Era for Computing Research ACM Transitions to Full Open Access ACM is tr… div.slick-slide > div > div.slide > div.acm-banner-container
www.acm.org/binaries/bannerlarge/content/gallery/acm/banners/acm-open1.5 MiB1.3 MiB
Image button linking to Awards section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-awards.jpg529.9 KiB518.8 KiB
Image button linking to Publich Policy section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-public-policy.jpg510.7 KiB499.6 KiB
Image button linking to Conferences section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-conferences.jpg483.5 KiB472.4 KiB
Image button linking to Publications section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-publications.jpg471.3 KiB460.3 KiB
ACM Awards Celebrating Innovation and Lasting Contributions ACM recognizes exc… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/7_award...588.9 KiB437.4 KiB
Image button linking to Education section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-education.jpg445.8 KiB434.7 KiB
Image button linking to Membership section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-membership.jpg434.0 KiB422.9 KiB
Image button linking to Special Interest Groups section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-sigs.jpg419.6 KiB408.5 KiB
In-Depth Interviews ACM ByteCast ACM's podcast series at the intersection of c… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/carouse...379.1 KiB263.4 KiB
2026 ACM General Election div.row > div.medium-4 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/general_election.jpg212.0 KiB200.9 KiB
acm symbol div.row > div.medium-4 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/acm-sym-branded.jpg203.2 KiB192.1 KiB
What's Happening in and Around ACM ACM Updates The latest goings-on in the wor… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/generic...258.8 KiB143.2 KiB
Newsmakers ACM Members in the News Members whose achievements have made the he… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/generic...257.1 KiB141.5 KiB
Image button linking to Diversity Equity & Inclusion section div.row > div.medium-12 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/diversit...123.4 KiB112.3 KiB
2025 ACM Prize recipient Matei Zaharia div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...107.4 KiB97.4 KiB
Association for Computing Machinery Advancing Computing as a Science & Professi… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/2_gener...248.1 KiB96.5 KiB
Focused Lectures On Demand ACM TechTalks Talks by industry experts, ACM award … div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/carouse...208.5 KiB92.9 KiB
Ricardo Baeza-Yates div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/r...97.4 KiB87.4 KiB
Message from ACM President Yannis Ioannidis about ACM's Transition to OA and Re… div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/publicat...93.1 KiB83.1 KiB
Communications of the ACM The Most Trusted Source The leading online and print… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/carouse...230.8 KiB79.3 KiB
Ambassador for ACM Program div.row > div.medium-12 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/ambassad...88.8 KiB77.7 KiB
ACM Transitions to Full Open Access div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/publicat...83.0 KiB73.0 KiB
ACM A.M. Turing Award laureate Michael O. Rabin div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...73.1 KiB63.1 KiB
ACM Queue div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/publicat...70.3 KiB59.2 KiB
Federal Funding of Academic Research div.row > div.medium-12 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/publicat...51.4 KiB40.7 KiB
ACM Digital Library Research, Discovery and Networking The full-text collectio… div.slick-slide > div > div.slide > div.acm-banner-container
/binaries/bannerlarge/content/gallery/acm/banners/carouse...190.2 KiB38.6 KiB

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:147.822 label:Time to first byte subpart:timeToFirstByte] map[duration:2507.018 label:Resource load delay subpart:resourceLoadDelay] map[duration:63.797 label:Resource load duration subpart:resourceLoadDuration] map[duration:139.658 label:Element render delay subpart:elementRenderDelay]]
lhId: page-27-DIV
nodeLabel: Association for Computing Machinery Advancing Computing as a Science & Professi…
path: 1,HTML,1,BODY,14,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,DIV,0,DIV,0,DIV,0,DIV
selector: div#slick-slide20 > div > div.slide > div.acm-banner-container
snippet: <div class="acm-banner-container" style="background: url(&quot;/binaries/bannerlarge/content/gallery/acm/banners/2_generi…&quot;);">

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-27-DIV
nodeLabel: Association for Computing Machinery Advancing Computing as a Science & Professi…
path: 1,HTML,1,BODY,14,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,DIV,0,DIV,0,DIV,0,DIV
selector: div#slick-slide20 > div > div.slide > div.acm-banner-container
snippet: <div class="acm-banner-container" style="background: url(&quot;/binaries/bannerlarge/content/gallery/acm/banners/2_generi…&quot;);">

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
consent.cookiebot.com/uc.js35.7 KiB2.1 s
www.acm.org/js/classList.js951 B469 ms
www.acm.org/js/modernizr.js4.8 KiB619 ms
www.acm.org/js/analytics.js?=11.3 KiB919 ms
www.acm.org/js/webfontloader.js626 B469 ms
www.acm.org/css/acm.css?antiCache=174490700593739.4 KiB1.5 s
cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick-theme.min.css1.2 KiB792 ms
cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.css1.1 KiB792 ms
www.acm.org/css/acm-blessed1.css?z=26235.2 KiB1.7 s

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.

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

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

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: 807 ms
URLTime Spent
acm.org/807 ms
www.acm.org/0.0 ms

These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS

Why this matters

Performance issues directly impact user engagement and conversion rates.

ElementLayout shift score
ACM ELECTIONS Vote in the 2026 ACM General Election - Ballots Due by 22 May at … div#main > div#maincontent > article#SkipTarget > div.row
0.440
On 16 April, ACM Professional Members in good standing as of 1 April 2026 were … div.medium-8 > div.text-wrap > div.dek > p
0.012
0.000

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 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 115.7 KiB
URLTransfer SizeEst Savings
www.acm.org/css/acm.css?antiCache=174490700593739.2 KiB37.5 KiB
www.acm.org/css/acm-blessed1.css?z=26234.9 KiB33.7 KiB
/assets/new_embed-2552d8d62d9c60f59b3b11a5d083d1ebd090c72...33.2 KiB33.2 KiB
13.5 KiB11.3 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: 3.8 s 558.2 KiB
URLTransfer SizeEst Savings
www.googletagmanager.com/gtm.js?id=GTM-5G4WDJNB111.4 KiB71.7 KiB
www.googletagmanager.com/gtm.js?id=GTM-M3TS27JG111.4 KiB71.7 KiB
www.googletagmanager.com/gtm.js?id=GTM-W4CLDXL3111.4 KiB71.6 KiB
s.swiftypecdn.com/install/v2/st.js111.6 KiB69.3 KiB
www.googletagmanager.com/gtm.js?id=GTM-5BVDRXH121.5 KiB68.3 KiB
www.googletagmanager.com/gtag/js?id=G-RX448GM2EK&cx=c&gtm=4e64h1165.1 KiB66.3 KiB
www.googletagmanager.com/gtag/js?id=AW-968097012&cx=c&gtm=4e64h1145.5 KiB64.6 KiB
www.acm.org/js/acm.js?antiCache=174490700593776.6 KiB49.7 KiB
/9bb7fc8b-05a2-4292-85e6-45213b19c5ff/cc.js?renew=false&r...104.7 KiB25.0 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.

URLTotal CPU TimeScript EvaluationScript Parse
consent.cookiebot.com/uc.js1.9 s1.3 s24 ms
Unattributable1.7 s22 ms0.0 ms
www.acm.org/1.3 s12 ms3.4 ms
/9bb7fc8b-05a2-4292-85e6-45213b19c5ff/cc.js?renew=false&r...584 ms269 ms38 ms
www.googletagmanager.com/gtag/js?id=G-RX448GM2EK&cx=c&gtm=4e64h1476 ms399 ms68 ms
s.swiftypecdn.com/install/v2/st.js330 ms253 ms58 ms
www.acm.org/cdn-cgi/challenge-platform/scripts/jsd/main.js323 ms299 ms4.9 ms
www.googletagmanager.com/gtag/js?id=AW-968097012&cx=c&gtm=4e64h1259 ms179 ms39 ms
www.googletagmanager.com/gtm.js?id=GTM-5BVDRXH210 ms172 ms36 ms
www.acm.org/js/acm.js?antiCache=1744907005937140 ms69 ms33 ms
www.googletagmanager.com/gtm.js?id=GTM-W4CLDXL3137 ms100 ms36 ms
www.acm.org/js/modernizr.js119 ms56 ms2.4 ms
www.googletagmanager.com/gtm.js?id=GTM-5G4WDJNB118 ms82 ms34 ms
www.googletagmanager.com/gtm.js?id=GTM-M3TS27JG103 ms74 ms28 ms
snap.licdn.com/li.lms-analytics/insight.min.js90 ms77 ms7.6 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.

CategoryTime Spent
Script Evaluation3.4 s
Other1.9 s
Style & Layout1.6 s
Script Parsing & Compilation423 ms
Parse HTML & CSS393 ms
Rendering125 ms
Garbage Collection124 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 reasonFailure type
The page has an unload handler in the main frame.Actionable

Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 13.9 KiB
URLTransfer SizeEst Savings
www.acm.org/css/acm-blessed1.css?z=26235.2 KiB7.4 KiB
www.acm.org/css/acm.css?antiCache=174490700593739.4 KiB6.5 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.

URLTransfer Size
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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
2026 ACM General Election div.row > div.medium-4 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/general_election.jpg
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2025 ACM Prize recipient Matei Zaharia div.row > div.medium-4 > a.js-no-link-icon > img
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acm symbol div.row > div.medium-4 > a.js-no-link-icon > img
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Ricardo Baeza-Yates div.row > div.medium-4 > a.js-no-link-icon > img
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ACM A.M. Turing Award laureate Michael O. Rabin div.row > div.medium-4 > a.js-no-link-icon > img
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Message from ACM President Yannis Ioannidis about ACM's Transition to OA and Re… div.row > div.medium-4 > a.js-no-link-icon > img
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ACM Transitions to Full Open Access div.row > div.medium-4 > a.js-no-link-icon > img
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2025 ACM Prize recipient Matei Zaharia div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...
acm symbol div.row > div.medium-4 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/acm-sym-branded.jpg
Ricardo Baeza-Yates div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/r...
ACM A.M. Turing Award laureate Michael O. Rabin div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/people/m...
Message from ACM President Yannis Ioannidis about ACM's Transition to OA and Re… div.row > div.medium-4 > a.js-no-link-icon > img
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ACM Transitions to Full Open Access div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/publicat...
Image button linking to Publications section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-publications.jpg
Image button linking to Conferences section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-conferences.jpg
Image button linking to Special Interest Groups section div.row > div.medium-12 > a.js-no-link-icon > img
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Image button linking to Membership section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-membership.jpg
Image button linking to Awards section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-awards.jpg
Image button linking to Education section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-education.jpg
Image button linking to Diversity Equity & Inclusion section div.row > div.medium-12 > a.js-no-link-icon > img
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Image button linking to Publich Policy section div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/og-public-policy.jpg
acm symbol div.row > div.medium-4 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/acm-sym-branded.jpg
Federal Funding of Academic Research div.row > div.medium-12 > a.js-no-link-icon > img
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ACM Queue div.row > div.medium-4 > a.js-no-link-icon > img
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Ambassador for ACM Program div.row > div.medium-12 > a.js-no-link-icon > img
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div.row > div.medium-12 > a.js-no-link-icon > img div.row > div.medium-12 > a.js-no-link-icon > img
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techpacks div.row > div.medium-12 > a.js-no-link-icon > img
www.acm.org/binaries/ctaimagelarge/content/gallery/acm/ctas/techpacks.jpg
div.row > div.medium-4 > a.js-no-link-icon > img div.row > div.medium-4 > a.js-no-link-icon > img
/binaries/ctaimagelarge/content/gallery/acm/ctas/membersh...
Facebook logo ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_facebook.png
Twitter logo ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_x_twitter.png
LinkedIn logo ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_linkedin.png
Reddit logo ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_reddit.png
YouTube logo ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_youtube.png
Instagram ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_instagram.png
Flickr ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_flickr.png
Mastodon ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_mastodon.png
Bluesky ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_bluesky.png
WeChat ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_wechat.png
Substack ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_substack.png
Email ul.footer__social > li > a.js-no-link-icon > img
www.acm.org/binaries/content/gallery/acm/social-media/icon_mail.png
ACM Logo div.logo-section > div.navbar-header > a.js-no-link-icon > img.img-responsive
www.acm.org/binaries/content/gallery/global/top-menu/acm_logo_mobile.svg

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

●Optimize DOM size
●Modern HTTP
●Optimize viewport for mobile
●Minify JavaScript
●User Timing marks and measures 5 user timings
●Avoid long main-thread tasks 20 long tasks found
●Network Requests
●Network Round Trip Times 40 ms
●Server Backend Latencies 100 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 120 ms
○INP breakdown
○Avoid non-composited animations
87

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.

Names and labels

Screen reader users rely on frame titles to describe the contents of frames. Learn more about frame titles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.medium-12 > div.image-video-container > div.video-wrapper > iframe#ytplayer div.medium-12 > div.image-video-container > div.video-wrapper > iframe#ytplayer

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
nav.top-bar > ul.title-area > li.toggle-topbar > a nav.top-bar > ul.title-area > li.toggle-topbar > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.row > div.medium-12 > h2.text-center > a div.row > div.medium-12 > h2.text-center > a
div.cta > div.row > div.medium-12 > a.js-no-link-icon div.cta > div.row > div.medium-12 > a.js-no-link-icon
div.cta > div.row > div.medium-4 > a.js-no-link-icon div.cta > div.row > div.medium-4 > a.js-no-link-icon

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.

Best practices

Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.

Why this matters

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

Source: MDN Permissions-Policy

Failing Elements
head > meta head > meta

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
Home div > ul.footer__legal > li > a
Sitemap div > ul.footer__legal > li > a
Contact Us div > ul.footer__legal > li > a
Member Services div > ul.footer__legal > li > a
Social Media Policy div > ul.footer__legal > li > a
Accessibility div > ul.footer__legal > li > a
Cookie Declaration div > ul.footer__legal > 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
●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
●Form elements have associated labels
●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.
●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
●`[lang]` attributes have a valid value
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
●All heading elements contain content.
●Elements with visible text labels have matching accessible names.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements 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
○`<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.
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○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.
81

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
AttributionReporting
snap.licdn.com/li.lms-analytics/insight.min.js
SharedStorage
www.acm.org/cdn-cgi/challenge-platform/scripts/jsd/main.js
StorageType.persistent is deprecated. Please use standardized navigator.storage instead.
www.acm.org/cdn-cgi/challenge-platform/scripts/jsd/main.js
Fledge
www.acm.org/cdn-cgi/challenge-platform/scripts/jsd/main.js
Unload event listeners are deprecated and will be removed.
consent.cookiebot.com/uc.js line 1, col 17119
●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
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
83

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.

Content Best Practices

Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Link destinationLink Text
www.acm.org/publications/openaccessRead More
www.acm.org/about-acmLearn More
www.acm.org/publications/openaccessRead More
www.acm.org/about-acmLearn More
www.acm.org/publications/openaccessRead More

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
●Page has successful HTTP status code
●Links are crawlable
●robots.txt is valid
●Image elements have `[alt]` attributes
●Document has a valid `hreflang`
○Document has a valid `rel=canonical`

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