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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.

26

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
connect.facebook.net/en_US/fbevents.js1200.0 s96.6 KiB
js.hs-analytics.net/analytics/1776889800000/22740101.js300.0 s42.3 KiB
/signals/config/1645398289372783?v=2.9.303&r=stable&domai...1200.0 s44.8 KiB
js.hs-banner.com/v2/22740101/banner.js300.0 s26.5 KiB
www.redditstatic.com/ads/pixel.js60.0 s19.0 KiB
/signals/config/2998277347144829?v=2.9.303&r=stable&domai...1200.0 s18.2 KiB
snap.licdn.com/li.lms-analytics/insight.min.js86400.0 s18.7 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...86400.0 s10.7 KiB
js.hsadspixel.net/pixels.js600.0 s3.9 KiB
js.hs-scripts.com/22740101.js90.0 s1.0 KiB
static.addtoany.com/menu/page.js86400.0 s2.2 KiB
/lt/1.css?apiType=css&c=1c75c36c-a46a-4891-8bfa-e317e4c2d...1.0 s671 B
/rp.gif?ts=1776889900716&id=a2_fzw3bgak4b5o&event=PageVis...0.0 ms666 B
/collect?v=2&fmt=js&pid=3073724&time=1776889900897&li_ads...0.0 ms429 B
www.gstatic.com/recaptcha/api2/logo_48.png604800.0 s2.3 KiB
/tr/?id=1645398289372783&ev=PageView&dl=https%3A%2F%2Fcom...0.0 ms16 B
/tr/?id=2998277347144829&ev=PageView&dl=https%3A%2F%2Fcom...0.0 ms16 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
/a?id=AW-1065537524&v=3&t=t&pid=1506112870&gtm=45be64k0v9...0.0 ms11 B
www.gstatic.com/recaptcha/api2/logo_48.png604800.0 s0 B

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.

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:1.664 source:map[column:197 line:950 type:source-location url:https://www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0 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:11.855 source:map[column:145132 line:3547 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/assets/js/source.dev.js?ver=0.0.3 urlProvider:network]] map[reflowTime:48.079 source:map[column:52029 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:0.443 source:map[column:52087 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:0.305 source:map[column:52151 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:41.382 source:map[column:51353 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:3.192 source:map[column:51375 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:11.26 source:map[type:text value:[unattributed]]] map[reflowTime:1.916 source:map[column:55 line:947 type:source-location url:https://www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0 urlProvider:network]] map[reflowTime:0.473 source:map[column:332 line:412 type:source-location url:https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js urlProvider:network]] map[reflowTime:0.072 source:map[column:99 line:216 type:source-location url:https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js urlProvider:network]] map[reflowTime:0.435 source:map[column:86058 line:22 type:source-location url:https://js.hs-analytics.net/analytics/1776889800000/22740101.js urlProvider:network]] map[reflowTime:0.439 source:map[column:101328 line:22 type:source-location url:https://js.hs-analytics.net/analytics/1776889800000/22740101.js 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
Timelines div.slider__container > a > div.slider__img > img
computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg95.8 KiB84.9 KiB
Collections div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/cyc-065-crop-1-760x0-c-defaul...93.0 KiB80.1 KiB
Source Code div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...87.2 KiB76.4 KiB
Tours div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...78.1 KiB67.2 KiB
Exhibits div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...62.0 KiB48.2 KiB
background image section.hero > div.hero-background > picture > img
/wp-content/uploads/2025/06/2024-10-Chatbot-Exhibit-SIS-1...63.8 KiB32.8 KiB
Podcast div.slider__container > a > div.slider__img > img
/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...43.0 KiB32.6 KiB
Fellow Awards div.slider__container > a > div.slider__img > img
/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...39.4 KiB30.9 KiB
TechFest div.slider__container > a > div.slider__img > img
/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...20.8 KiB15.7 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-5-IMG
nodeLabel: background image
path: 1,HTML,1,BODY,4,DIV,0,SECTION,0,DIV,0,PICTURE,1,IMG
selector: section.hero > div.hero-background > picture > img
snippet: <img src="https://computerhistory.org/wp-content/uploads/2025/06/2024-10-Chatbot-Exh…" alt="background image">

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

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

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.

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.

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 Evaluation7.0 s
Other1.4 s
Script Parsing & Compilation1.2 s
Style & Layout946 ms
Garbage Collection360 ms
Parse HTML & CSS105 ms
Rendering71 ms

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
Source Code div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...
Source Code div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...
Tours div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...
Tours div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...
Timelines div.slider__container > a > div.slider__img > img
computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg
Timelines div.slider__container > a > div.slider__img > img
computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg
Fellow Awards div.slider__container > a > div.slider__img > img
/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...
Fellow Awards div.slider__container > a > div.slider__img > img
/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...
Podcast div.slider__container > a > div.slider__img > img
/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
Collections div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/cyc-065-crop-1-760x0-c-defaul...
Podcast div.slider__container > a > div.slider__img > img
/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
Collections div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/cyc-065-crop-1-760x0-c-defaul...
Podcast div.slider__container > a > div.slider__img > img
/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
TechFest div.slider__container > a > div.slider__img > img
/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
TechFest div.slider__container > a > div.slider__img > img
/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
TechFest div.slider__container > a > div.slider__img > img
/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
Exhibits div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...
Exhibits div.slider__container > a > div.slider__img > img
/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...
Computer History Museum Logo div.container > div.footer-content-3 > a.logo > img
computerhistory.org/wp-content/themes/bsdstarter/assets/img/chm-logo-short.svg
Computer History Museum Logo div.nav-section-top > div.logo > a.logo > img.full-logo
computerhistory.org/wp-content/themes/bsdstarter/assets/img/chm-logo-text.svg

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
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Minify CSS
●Minify JavaScript
●User Timing marks and measures 24 user timings
●Avoid long main-thread tasks 20 long tasks found
●Avoid non-composited animations 36 animated elements found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 140 ms
●Server Backend Latencies 190 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Avoid multiple page redirects
●Initial server response time was short Root document took 20 ms
○INP breakdown
○Avoid large layout shifts
96

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.

Navigation

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.related-articles__column > a > div.related-articles__content > h5 div.related-articles__column > a > div.related-articles__content > h5
Visit div.slider__container > div.slider__content > a > h5
div.related-articles__column > a > div.related-articles__content > h5 div.related-articles__column > a > div.related-articles__content > h5
CHM BLOG div.related-articles__column > a > div.related-articles__content > h5
Game for Grades 3–8 div.related-articles__column > a > div.related-articles__content > h5
div.related-articles__column > a > div.related-articles__content > h5 div.related-articles__column > a > div.related-articles__content > h5

These are opportunities to improve keyboard navigation in your application.

Best practices

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html.no-js html.no-js

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>`
●`[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 are distinguishable without relying on color.
●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.
●All heading elements contain content.
●Identical links have the same purpose.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Deprecated ARIA roles were not used
○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
○`[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
○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
○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>`.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Elements with visible text labels have matching accessible names.
○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
○`<td>` elements in a large `<table>` have one or more table headers.
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
●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
85

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
computerhistory.org/apple-at-50/Learn 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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