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· 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.

89

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
/main/images/tempImagehv5Jlm.2e16d0ba.fill-1060x780-c100....14400.0 s89.2 KiB
www.caltech.edu/static/CACHE/css/output.7e3001c3b76e.css86400.0 s73.5 KiB
/main/images/President_Rosenbaum-Campus_Celebra.2e16d0ba....14400.0 s32.2 KiB
/v/t51.82787-15/671798385_18582177727012321_6958694230070...1209600.0 s217.4 KiB
/main/images/1-Voyager_2-copy.2e16d0ba.fill-535x340-c100....14400.0 s30.1 KiB
/main/images/phase_micro.2e16d0ba.fill-710x400-c100.forma...14400.0 s29.5 KiB
/v/t51.82787-15/663139650_18579652564012321_3731338702900...1209600.0 s192.7 KiB
/main/images/AoT100_0409.2e16d0ba.fill-300x195.jpg14400.0 s26.2 KiB
/main/images/ChenInstitute.2e16d0ba.fill-300x195.jpg14400.0 s20.7 KiB
www.caltech.edu/static/CACHE/js/output.2500c9bd34d8.js86400.0 s34.1 KiB
/main/images/Science_Exchange_Vote_redblue.c0f16667.fill-...14400.0 s19.8 KiB
/v/t51.71878-15/670531793_930498332928159_292153058229562...1209600.0 s127.6 KiB
/main/images/Yu_Yu_Phua_Photo.ddbdbf2a.fill-710x400-c100....14400.0 s17.0 KiB
www.caltech.edu/static/theme-v7.0/img/flame.png3600.0 s12.8 KiB
/main/images/Minnich_Austin-T.12cfe109.fill-710x400-c100....14400.0 s15.0 KiB
/main/images/see_kim-watson-lecture-preshow-act.2e16d0ba....14400.0 s13.5 KiB
www.caltech.edu/static/www/img/caltech-weekly-logo.png3600.0 s9.7 KiB
/main/images/Mishra-Wang-Ultrafast-Imaging-Comb.2e16d0ba....14400.0 s11.2 KiB
/v/t51.71878-15/670311347_4253466034928050_61864710185319...1209600.0 s75.5 KiB
/main/images/Hutchcroft_Thomas-Faculty-2762.2e16d0ba.fill...14400.0 s10.6 KiB
www.caltech.edu/static/core/img/caltech-new-logo.png3600.0 s7.6 KiB
/main/images/05-Research-Impact-AI-and-Adv.2e16d0ba.fill-...14400.0 s7.7 KiB
/main/images/Ismagilov_Rustem-Human_Virome.2e16d0ba.fill-...14400.0 s6.6 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...86400.0 s10.7 KiB
/main/images/SSPD-1440x1060pixels48.2e16d0ba.fill-163x144...14400.0 s6.0 KiB
www.caltech.edu/static/theme-v7.0/img/bg-footer.png?2a780efa35413600.0 s4.0 KiB
/main/images/STSCI-H-atlas-B-.2e16d0ba.fill-710x400-c100....14400.0 s4.7 KiB
www.caltech.edu/static/theme-v7.0/img/icon-footerpin.png3600.0 s2.1 KiB
www.caltech.edu/static/CACHE/js/output.54b9aeca30a0.js86400.0 s2.8 KiB
www.caltech.edu/static/airspace/img/icon-chevron-white-left.png3600.0 s1.3 KiB
www.caltech.edu/static/wagtail_menu/img/icon-search.png3600.0 s1.3 KiB
www.caltech.edu/static/airspace/js/jquery.mousewheel.min.js3600.0 s1.2 KiB
www.caltech.edu/static/wagtail_menu/img/icon-chevron-orange.png3600.0 s587 B
www.caltech.edu/static/airspace/img/icon-chevron-left.png3600.0 s464 B
www.caltech.edu/static/wagtailadmin/js/icons.js?v=38cff7383600.0 s463 B
www.caltech.edu/static/airspace/img/icon-chevron-white-right.png3600.0 s458 B
www.caltech.edu/static/airspace/img/icon-chevron-right.png3600.0 s458 B
www.caltech.edu/static/wagtail_menu/img/icon-chevron-grey-550.png3600.0 s453 B
www.caltech.edu/static/wagtail_menu/img/menu-burger.png3600.0 s169 B

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.

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:86.135 source:map[type:text value:[unattributed]]]]

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
Did you know? Before Los Angeles could clear away its notorious smog, Caltech… div.instagram-block > a.instagram-block__post > div.instagram-block__post__image > img.instagram-block__post__image__img
/v/t51.82787-15/671798385_18582177727012321_6958694230070...217.3 KiB202.0 KiB
Techer to Techer: What is your favorite house tradition? #Caltech div.instagram-block > a.instagram-block__post > div.instagram-block__post__image > img.instagram-block__post__image__img
/v/t51.82787-15/663139650_18579652564012321_3731338702900...192.7 KiB165.4 KiB
Did you know modern telescopes generate more data than any human could ever ana… div.instagram-block > a.instagram-block__post > div.instagram-block__post__image > img.instagram-block__post__image__img
/v/t51.71878-15/670531793_930498332928159_292153058229562...127.6 KiB100.3 KiB
Techer to Techer: What inspired you to choose your major? #Caltech div.instagram-block > a.instagram-block__post > div.instagram-block__post__image > img.instagram-block__post__image__img
/v/t51.71878-15/670311347_4253466034928050_61864710185319...75.4 KiB48.2 KiB
balloons float over a crowd of people who watch as President Rosenbaum speaks t… div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/President_Rosenbaum-Campus_Celebra.2e16d0ba....32.0 KiB27.8 KiB
People gather around a telescope on a lawn with Beckman Auditorium in the backg… div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/AoT100_0409.2e16d0ba.fill-300x195.jpg25.9 KiB21.7 KiB
Colorful oblong shapes div.article-teaser__image-container > a > picture > img.img-fluid
/main/images/phase_micro.2e16d0ba.fill-710x400-c100.forma...29.2 KiB19.9 KiB
Chen Institute, and angular building with sections or wood panels and reflectiv… div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/ChenInstitute.2e16d0ba.fill-300x195.jpg20.5 KiB16.3 KiB
div.did-you-know-block__tiles__tile > a.did-you-know-block__tiles__tile__link > div.did-you-know-block__tiles__tile__image > img div.did-you-know-block__tiles__tile > a.did-you-know-block__tiles__tile__link > div.did-you-know-block__tiles__tile__image > img
/main/images/Science_Exchange_Vote_redblue.c0f16667.fill-...19.2 KiB16.0 KiB
body.www > footer.footer-container > div.footer > img.footer__torch body.www > footer.footer-container > div.footer > img.footer__torch
www.caltech.edu/static/theme-v7.0/img/flame.png12.7 KiB12.1 KiB
two people stand behind a table with bottles and an apparatus that is lit up wi… div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/see_kim-watson-lecture-preshow-act.2e16d0ba....12.9 KiB8.7 KiB
The Caltech Weekly section.block-NowAtCaltechBlock > div.now-at-caltech-block > h2.now-at-caltech-block__title > img.now-at-caltech-block__title__logo
www.caltech.edu/static/www/img/caltech-weekly-logo.png9.7 KiB7.2 KiB
Caltech header.width-1440-container > div.header > a.header__homepage-link > img.header__wordmark
www.caltech.edu/static/core/img/caltech-new-logo.png7.5 KiB6.8 KiB
A man with a beard, wearing goggles holds a device while looking into a flame w… div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/Mishra-Wang-Ultrafast-Imaging-Comb.2e16d0ba....10.9 KiB6.7 KiB
Tom Hutchcroft writes on a chalkboard wall div.photo-gallery-block > div.photo-gallery-block__gallery > button.photo-gallery-block__zoom > img.photo-gallery-block__image
/main/images/Hutchcroft_Thomas-Faculty-2762.2e16d0ba.fill...10.3 KiB6.1 KiB

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-15-IMG
nodeLabel: Vesselin and Kimmy headshots
path: 1,HTML,1,BODY,6,MAIN,3,SECTION,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,DIV,0,DIV,0,DIV,0,PICTURE,4,IMG
selector: div.news-carousel__image-wrapper > div.news-carousel__teaser > picture > img.news-carousel__image
snippet: <img alt="Vesselin and Kimmy headshots" class="news-carousel__image" decoding="async" height="780" loading="lazy" src="https://caltech-prod.resources.caltech.edu/main/images/tempImagehv5Jlm.2e1…" width="1060">

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
cdnjs.cloudflare.com/ajax/libs/apexcharts/5.3.2/apexcharts.min.js125.3 KiB443 ms
www.caltech.edu/static/CACHE/css/output.7e3001c3b76e.css73.5 KiB247 ms
cdn.datatables.net/1.12.1/js/jquery.dataTables.min.js29.5 KiB81 ms
cdn.datatables.net/1.12.1/css/dataTables.bootstrap4.min.css1.9 KiB221 ms
www.caltech.edu/static/wagtailadmin/js/icons.js?v=38cff738463 B
cdnjs.cloudflare.com/ajax/libs/clamp-js/0.7.0/clamp.js2.9 KiB225 ms
cdn.datatables.net/responsive/2.3.0/css/responsive.dataTables.min.css1.4 KiB
cdn.datatables.net/responsive/2.3.0/js/dataTables.responsive.min.js6.0 KiB
cdn.datatables.net/1.12.1/js/dataTables.bootstrap4.min.js2.1 KiB
code.jquery.com/jquery-3.3.1.min.js29.9 KiB283 ms
www.caltech.edu/static/CACHE/js/output.54b9aeca30a0.js2.8 KiB

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

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: 90 ms 67.2 KiB
URLTransfer SizeEst Savings
www.caltech.edu/static/CACHE/css/output.7e3001c3b76e.css73.5 KiB67.2 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: 320 ms 397.5 KiB
URLTransfer SizeEst Savings
cdnjs.cloudflare.com/ajax/libs/apexcharts/5.3.2/apexcharts.min.js124.7 KiB116.5 KiB
cdnjs.cloudflare.com/ajax/libs/mathjax/3.2.2/es5/tex-mml-chtml.min.js199.4 KiB99.0 KiB
www.googletagmanager.com/gtm.js?id=GTM-P8H9J4S131.6 KiB65.7 KiB
www.googletagmanager.com/gtag/js?id=G-7RL83EX4D4&cx=c&gtm=4e64h1153.4 KiB64.9 KiB
www.caltech.edu/static/CACHE/js/output.2500c9bd34d8.js34.1 KiB27.1 KiB
cdn.datatables.net/1.12.1/js/jquery.dataTables.min.js29.2 KiB24.3 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 2.4 KiB
URLTransfer SizeEst Savings
cdnjs.cloudflare.com/ajax/libs/anchor-js/5.0.0/anchor.js4.3 KiB2.4 KiB

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

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: 407 ms
URLTime Spent
caltech.edu/407 ms
www.caltech.edu/0.0 ms
●Time to Interactive 2.4 s
●Max Potential First Input Delay 130 ms
●Layout shift culprits
●Optimize DOM size
●Font display
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Minify CSS
●Avoids enormous network payloads Total size was 1,919 KiB
●User Timing marks and measures 5 user timings
●JavaScript execution time 0.4 s
●Minimizes main-thread work 0.8 s
●Avoid long main-thread tasks 3 long tasks found
●Image elements have explicit `width` and `height`
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 70 ms
●Server Backend Latencies 30 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 40 ms
●Avoid large layout shifts 1 layout shift found
○INP breakdown
○Avoid non-composited animations
89

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

ARIA

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
April 20, 2026 Caltech Faculty Honored with New Horizons Prizes Vesselin Dimit… div.homepage-top-layout-block__left-column-content > section.block-NewsCarouselBlock > div#3f5eec8e-12dd-4173-8a0c-84d4572c0e00 > div.carousel-inner
Beckman Institute Brinson Exploration Hub Richard N. Merkin Institute for Trans… section.block-AirspaceImageLinkGridCarouselBlock > div.grid-carousel > div#20d85a6f-782d-4e5a-9135-63f951fd9f0b > div.grid-carousel__carousel-inner

When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more about input field labels.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
April 20, 2026 Caltech Faculty Honored with New Horizons Prizes Vesselin Dimit… div.homepage-top-layout-block__left-column-content > section.block-NewsCarouselBlock > div#3f5eec8e-12dd-4173-8a0c-84d4572c0e00 > div.carousel-inner
Beckman Institute Brinson Exploration Hub Richard N. Merkin Institute for Trans… section.block-AirspaceImageLinkGridCarouselBlock > div.grid-carousel > div#20d85a6f-782d-4e5a-9135-63f951fd9f0b > div.grid-carousel__carousel-inner

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.

Contrast

Low-contrast text is difficult or impossible for many users to read. Link text that is discernible improves the experience for users with low vision. Learn how to make links distinguishable.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Sarah Elizabeth McCandless div.events-block__events__event__speakers > div.seminar-speaker > span.seminar-speaker__name > a
Roshan Misra div.events-block__events__event__speakers > div.seminar-speaker > span.seminar-speaker__name > a

These are opportunities to improve the legibility of your content.

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
Menu div.header > nav.header__slide-menu-and-search > div.header__slide-menu > button.slide-menu__opener
○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]`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
●Document has a main landmark.
●Deprecated ARIA roles were not used
●ARIA IDs are unique
●Uses ARIA roles only on compatible elements
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Elements with `role="dialog"` or `role="alertdialog"` 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
○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
○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.
○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.
100

Best Practices

●Uses HTTPS
●Avoids deprecated APIs
●Avoids third-party cookies
●Allows users to paste into input fields
●Avoids requesting the geolocation permission on page load
●Avoids requesting the notification permission on page load
●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
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
○Ensure proper origin isolation with COOP
○Mitigate clickjacking with XFO or CSP
92

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

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.caltech.edu/about/news/nayla-abney-stem-and-soccer-standoutread more
breakthrough.caltech.edu/story/david-fager-caltech-scholarship/Read more
breakthrough.caltech.edu/story/ralph-adolphs-brain-mind/Read more
breakthrough.caltech.edu/story/katherine-de-kleer-io-jupiter-volcanoes-caltech/Read 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
●Document has a meta description
●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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