Lighthouse Desktop

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

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
cdn.optimizely.com/js/29864900014.js	120.0 s	141.2 KiB
connect.facebook.net/en_US/fbevents.js	1200.0 s	96.6 KiB
edge.fullstory.com/s/fs.js	3600.0 s	79.8 KiB
cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js	86400.0 s	129.0 KiB
cdn.evgnet.com/beacon/emdmilliporecorp/prod/scripts/evergage.min.js	120.0 s	49.3 KiB
tag.demandbase.com/bccb5bc7.min.js	3600.0 s	50.1 KiB
d1igp3oop3iho5.cloudfront.net/v2/J4HDbvH5rl2QuF5CfIvJZg/zaius-min.js	0.0 ms	38.1 KiB
/logos/e0f8496a-cdec-4d5c-8c10-313a8c4189a9/073ad8c0-9e7a...	86400.0 s	80.2 KiB
maestro.my.site.com/ESWMessagingService1730092965382/assets/js/bootstrap.min.js	34.0 s	26.5 KiB
/signals/config/1671231489763896?v=2.9.303&r=stable&domai...	1200.0 s	23.3 KiB
www.redditstatic.com/ads/pixel.js	60.0 s	19.0 KiB
rs.fullstory.com/rec/integrations?OrgId=15R99F&isInFrame=false&isNative=false	0.0 ms	16.8 KiB
edge.fullstory.com/datalayer/v4/latest.js	3600.0 s	13.5 KiB
scripts.clarity.ms/0.8.59/clarity.js	86400.0 s	26.2 KiB
snap.licdn.com/li.lms-analytics/insight.min.js	86400.0 s	18.7 KiB
bat.bing.com/p/insights/s/0.8.59	86400.0 s	15.6 KiB
www.sigmaaldrich.com/akam/13/6efc6afe	21600.0 s	9.2 KiB
/SIE/?Q_ZID=ZN_6PrR1PrkKGQdoc6	3600.0 s	4.6 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
/dxjsmodule/12.1a2b7192fd54e87d3971.chunk.js?Q_CLIENTVERS...	604800.0 s	35.8 KiB
/dxjsmodule/CoreModule.js?Q_CLIENTVERSION=2.46.0&Q_CLIENT...	604800.0 s	30.9 KiB
/dxjsmodule/FeedbackButtonModule.js?Q_CLIENTVERSION=2.46....	604800.0 s	19.4 KiB
/dxjsmodule/37.7ea1ffe71ad8c0799cc1.chunk.js?Q_CLIENTVERS...	604800.0 s	18.6 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	14.1 KiB
/api/v3/ip.json?key=IOrVTGsJH0Xu0nVmm7XWY3q2bxdFFJNRl3vrS...	0.0 ms	1.3 KiB
cdn.cookielaw.org/logos/static/powered_by_logo.svg	86400.0 s	2.7 KiB
/dxjsmodule/1.bc67e778235741631577.chunk.js?Q_CLIENTVERSI...	604800.0 s	7.1 KiB
/rp.gif?ts=1776900262609&id=t2_9szsajw&event=PageVisit&m....	0.0 ms	666 B
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.8 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.6 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.5 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.4 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.3 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.2 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.2 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.2 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.2 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.1 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.1 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/home...	1296000.0 s	5.0 KiB
/collect?v=2&fmt=js&pid=9130&time=1776900262589&li_adsId=...	0.0 ms	453 B
partners.tremorhub.com/sync?UIDM=a34bbb50-1346-41ec-9ab9-c490d5e682d8	0.0 ms	391 B
cdn3.optimizely.com/js/geo4.js	0.0 ms	307 B
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	1.5 KiB
/dxjsmodule/7.f7df015b06d8a90ce822.chunk.js?Q_CLIENTVERSI...	604800.0 s	1.4 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	1.2 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	1.1 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	1.1 KiB
/deepweb/assets/sigmaaldrich/marketing/global/images/icon...	1296000.0 s	987 B
/tr/?id=1671231489763896&ev=PageView&dl=https%3A%2F%2Fwww...	0.0 ms	16 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.

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.

URL	Est Savings
/static/fonts/Noto_Sans/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iP...	315 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:22.58 source:map[column:131353 line:1 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/framework-8593b37603e77b1e.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:0.65 source:map[column:6794 line:1 type:source-location url:https://www.sigmaaldrich.com/akam/13/6efc6afe urlProvider:network]] map[reflowTime:7.255 source:map[column:300157 line:6 type:source-location url:https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js urlProvider:network]] map[reflowTime:0.456 source:map[column:300501 line:6 type:source-location url:https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js urlProvider:network]] map[reflowTime:3.288 source:map[column:354446 line:6 type:source-location url:https://cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js urlProvider:network]] map[reflowTime:4.905 source:map[column:30170 line:0 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/2086-9972f43719381593.js urlProvider:network]] map[reflowTime:15.543 source:map[column:10256 line:0 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/1724-095cf23657f4497a.js urlProvider:network]] map[reflowTime:0.394 source:map[column:13536 line:0 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/2491-643b4801db58d3d2.js urlProvider:network]] map[reflowTime:1.657 source:map[column:261760 line:0 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/4768-9da82a5f9303cd97.js urlProvider:network]] map[reflowTime:0.081 source:map[column:15418 line:0 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/2491-643b4801db58d3d2.js urlProvider:network]] map[reflowTime:1.128 source:map[column:472098 line:3 type:source-location url:https://www.sigmaaldrich.com/_next/static/chunks/pages/_app-e8d8f0583ad6d04c.js urlProvider:network]]]

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:1984.6940002441406 label:Time to first byte subpart:timeToFirstByte] map[duration:2440.1439997558596 label:Resource load delay subpart:resourceLoadDelay] map[duration:67.188 label:Resource load duration subpart:resourceLoadDuration] map[duration:433.403 label:Element render delay subpart:elementRenderDelay]]

lhId: page-0-A

nodeLabel: Optimized. Tailored. Greener. New purification cartridges improve lab efficienc…

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

selector: div.aem-Grid > div.aem-GridColumn > div.aem-ms-cmp > a

snippet: <a href="/US/en/products/water-purification/milli-q-consumables" target="_self" ga_product="HomepageHero - LW Milli-Q® -TID000006356|HomepageHero - LW Milli-Q® -TID00…" style="background-image: url("/deepweb/assets/sigmaaldrich/marketing/global/image…");" data-gtm-vis-recent-on-screen31314132_1416="437" data-gtm-vis-first-on-screen31314132_1416="437" data-gtm-vis-total-visible-time31314132_1416="100" data-gtm-vis-has-fired31314132_1416="1">

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-A

nodeLabel: Optimized. Tailored. Greener. New purification cartridges improve lab efficienc…

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

selector: div.aem-Grid > div.aem-GridColumn > div.aem-ms-cmp > a

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
www.sigmaaldrich.com/ruxitagentjs_ICA15789NPRTUVXfhqrux_10335260306043831.js	127.3 KiB	286 ms
www.sigmaaldrich.com/tmp/aem.e2668.css	18.3 KiB
www.sigmaaldrich.com/static/fonts/mkgaa.css	541 B
www.sigmaaldrich.com/static/fonts/noto-sans.css	1.1 KiB
cdn.optimizely.com/js/29864900014.js	141.2 KiB	383 ms
cdn.cookielaw.org/scripttemplates/otSDKStub.js	9.1 KiB	213 ms

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
Ace three-neck round-bottom flasks angled, capacity 500 mL, center joint: … `a#product-card-Z125741ALDRICH-top deals > div.css-1a4rhsa-mainContent-mainContentHeight > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/132/165/d3521...	11.9 KiB	11.2 KiB
Sodium chloride ACS reagent, ≥99.0% `a#product-card-S9888SIGALD-popular products > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/397/857/9...	8.4 KiB	8.3 KiB
Sigma-Aldrich `a#product-card-Z359998SIGMA-top deals > div.css-1a4rhsa-mainContent-mainContentHeight > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/assets/images/sigmaaldrich-no-image/sigmaaldrich-no-imag...	7.8 KiB	7.6 KiB
Ethyl alcohol, Pure 200 proof Molecular Biology `a#product-card-E7023SIGALD-popular products > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/429/462/0...	6.3 KiB	6.2 KiB
Methanol suitable for HPLC, ≥99.9% `a#product-card-34860SIGALD-popular products > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/279/355/c...	6.3 KiB	6.2 KiB
Hydrochloric acid ACS reagent, 37% `a#product-card-258148SIGALD-popular products > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/546/395/1...	5.8 KiB	5.7 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: 603 ms

URL	Time Spent
sigmaaldrich.com/	252 ms
www.sigmaaldrich.com/	351 ms
www.sigmaaldrich.com/US/en	0.0 ms

Keep the server response time for the main document short because all other requests depend on it. Learn more about the Time to First Byte metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 1.6 s

URL	Time Spent
www.sigmaaldrich.com/US/en	1.7 s

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.

Estimated savings: 40 ms 56.9 KiB

URL	Transfer Size	Est Savings
.css-rqv7gq-body { flex: 1 0 auto; } …	21.8 KiB	19.9 KiB
	22.6 KiB	19.7 KiB
www.sigmaaldrich.com/tmp/aem.e2668.css	17.9 KiB	17.2 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: 660 ms 1.3 MiB

URL	Transfer Size	Est Savings
www.sigmaaldrich.com/_next/static/chunks/pages/_app-e8d8f0583ad6d04c.js	558.8 KiB	260.0 KiB
www.sigmaaldrich.com/_next/static/chunks/8669-5cfc2e3fd97aca7a.js	137.5 KiB	115.4 KiB
www.sigmaaldrich.com/_next/static/chunks/4768-9da82a5f9303cd97.js	172.0 KiB	110.7 KiB
www.sigmaaldrich.com/_next/static/chunks/main-9b669c732468f591.js	107.1 KiB	85.1 KiB
cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js	128.8 KiB	68.6 KiB
www.googletagmanager.com/gtag/destination?id=DC-11536248&cx=c&gtm=4e64k1	129.7 KiB	62.3 KiB
www.googletagmanager.com/gtag/destination?id=DC-15223238&cx=c&gtm=4e64k1	129.1 KiB	61.3 KiB
www.googletagmanager.com/gtag/js?id=G-BQZS3WQYGJ&cx=c&gtm=4e64k1	165.4 KiB	60.8 KiB
www.googletagmanager.com/gtag/destination?id=AW-497007017&cx=c&gtm=4e64k1	140.8 KiB	60.0 KiB
www.googletagmanager.com/gtag/destination?id=AW-1034663491&cx=c&gtm=4e64k1	133.9 KiB	54.0 KiB
/gtm.js?id=GTM-TXMJ2GG&gtm_auth=&gtm_preview=&gtm_cookies...	205.9 KiB	48.6 KiB
www.sigmaaldrich.com/ruxitagentjs_ICA15789NPRTUVXfhqrux_10335260306043831.js	126.8 KiB	47.2 KiB
connect.facebook.net/en_US/fbevents.js	96.5 KiB	37.4 KiB
tag.demandbase.com/bccb5bc7.min.js	49.5 KiB	36.7 KiB
www.sigmaaldrich.com/_next/static/chunks/4958-9277997c572274af.js	52.2 KiB	34.8 KiB
www.sigmaaldrich.com/_next/static/chunks/9200-17489b815baf5f91.js	37.5 KiB	30.6 KiB
cdn.optimizely.com/js/29864900014.js	140.6 KiB	28.9 KiB
edge.fullstory.com/s/fs.js	79.2 KiB	27.9 KiB
cdn.evgnet.com/beacon/emdmilliporecorp/prod/scripts/evergage.min.js	48.7 KiB	24.6 KiB
maestro.my.site.com/ESWMessagingService1730092965382/assets/js/bootstrap.min.js	26.1 KiB	22.5 KiB
d1igp3oop3iho5.cloudfront.net/v2/J4HDbvH5rl2QuF5CfIvJZg/zaius-min.js	37.7 KiB	21.5 KiB
/dxjsmodule/12.1a2b7192fd54e87d3971.chunk.js?Q_CLIENTVERS...	35.7 KiB	20.9 KiB
/dxjsmodule/CoreModule.js?Q_CLIENTVERSION=2.46.0&Q_CLIENT...	30.9 KiB	20.9 KiB

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Total CPU Time	Script Evaluation	Script Parse
www.sigmaaldrich.com/_next/static/chunks/framework-8593b37603e77b1e.js	1.8 s	1.6 s	4.3 ms
www.sigmaaldrich.com/ruxitagentjs_ICA15789NPRTUVXfhqrux_10335260306043831.js	561 ms	482 ms	11 ms
Unattributable	558 ms	22 ms	0.0 ms
www.sigmaaldrich.com/US/en	496 ms	57 ms	2.9 ms
/gtm.js?id=GTM-TXMJ2GG&gtm_auth=&gtm_preview=&gtm_cookies...	441 ms	389 ms	27 ms
www.googletagmanager.com/gtag/destination?id=AW-497007017&cx=c&gtm=4e64k1	278 ms	263 ms	12 ms
edge.fullstory.com/s/fs.js	250 ms	214 ms	9.4 ms
/_next/static/chunks/pages/[country]/[language]-00abce956...	242 ms	220 ms	0.7 ms
www.sigmaaldrich.com/_next/static/chunks/pages/_app-e8d8f0583ad6d04c.js	215 ms	156 ms	59 ms
cdn.optimizely.com/js/29864900014.js	108 ms	86 ms	22 ms
cdn.evgnet.com/beacon/emdmilliporecorp/prod/scripts/evergage.min.js	98 ms	87 ms	6.7 ms
cdn.cookielaw.org/scripttemplates/202602.1.0/otBannerSdk.js	97 ms	62 ms	16 ms
www.googletagmanager.com/gtag/js?id=G-BQZS3WQYGJ&cx=c&gtm=4e64k1	87 ms	70 ms	15 ms
cdn.cookielaw.org/scripttemplates/otSDKStub.js	83 ms	82 ms	0.9 ms
www.sigmaaldrich.com/_next/static/chunks/7855.295cd659ed2e9f06.js	70 ms	57 ms	0.6 ms
www.googletagmanager.com/gtag/destination?id=DC-11536248&cx=c&gtm=4e64k1	69 ms	59 ms	10 ms
/dxjsmodule/12.1a2b7192fd54e87d3971.chunk.js?Q_CLIENTVERS...	69 ms	58 ms	3.7 ms
www.sigmaaldrich.com/_next/static/chunks/8912.ea5cf2dd607fc880.js	67 ms	63 ms	1.0 ms
tag.demandbase.com/bccb5bc7.min.js	61 ms	50 ms	9.4 ms
www.googletagmanager.com/gtag/destination?id=AW-1034663491&cx=c&gtm=4e64k1	56 ms	44 ms	11 ms
www.googletagmanager.com/gtag/destination?id=DC-15223238&cx=c&gtm=4e64k1	55 ms	43 ms	11 ms
/api/v3/ip.json?key=IOrVTGsJH0Xu0nVmm7XWY3q2bxdFFJNRl3vrS...	54 ms	52 ms	0.1 ms
scripts.clarity.ms/0.8.59/clarity.js	50 ms	47 ms	2.5 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	4.7 s
Other	766 ms
Script Parsing & Compilation	383 ms
Style & Layout	327 ms
Garbage Collection	169 ms
Parse HTML & CSS	112 ms
Rendering	87 ms

Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
Pages with cache-control:no-store header cannot enter back/forward cache.	Actionable
Pages whose main resource has cache-control:no-store cannot enter back/forward cache.	Not actionable
Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header.	Not 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 2.2 KiB

URL	Transfer Size	Est Savings
.css-rqv7gq-body { flex: 1 0 auto; } …	21.8 KiB	2.2 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 10.3 KiB

URL	Transfer Size	Est Savings
cdn.evgnet.com/beacon/emdmilliporecorp/prod/scripts/evergage.min.js	48.7 KiB	5.9 KiB
rs.fullstory.com/rec/integrations?OrgId=15R99F&isInFrame=false&isNative=false	16.7 KiB	4.4 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.sigmaaldrich.com/_next/static/chunks/pages/_app-e8d8f0583ad6d04c.js	562.3 KiB
www.sigmaaldrich.com/US/en	240.7 KiB
/gtm.js?id=GTM-TXMJ2GG&gtm_auth=&gtm_preview=&gtm_cookies...	206.3 KiB
www.sigmaaldrich.com/_next/static/chunks/4768-9da82a5f9303cd97.js	172.4 KiB
www.googletagmanager.com/gtag/js?id=G-BQZS3WQYGJ&cx=c&gtm=4e64k1	165.5 KiB
cdn.optimizely.com/js/29864900014.js	141.2 KiB
www.googletagmanager.com/gtag/destination?id=AW-497007017&cx=c&gtm=4e64k1	140.8 KiB
www.sigmaaldrich.com/_next/static/chunks/8669-5cfc2e3fd97aca7a.js	137.8 KiB
www.googletagmanager.com/gtag/destination?id=AW-1034663491&cx=c&gtm=4e64k1	133.9 KiB
www.googletagmanager.com/gtag/destination?id=DC-11536248&cx=c&gtm=4e64k1	129.8 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
MilliporeSigma `div.css-15529xt-menuLogoContainer > div.css-119kjtd-logoWrapper > a > img.css-8ycmhw-root-brandLogoSize`	www.sigmaaldrich.com/static/logos/purple/millipore_sigma.svg
Certified Reference Materials `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Microbial Filtration `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Solvents `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Microbial Culture Media `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Cell Separation Media for Research, Diagnostic & Pharmaceutical Applications `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Millex<sup>®</sup> Syringe Filters `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Glassware `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Pathogen Screening Kits, Instruments & Disposables `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Amicon<sup>®</sup> Centrifugals `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Millipore<sup>®</sup> Filter Membranes `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Milli-Q<sup>®</sup> Lab Water Purification Consumables `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...
Greener Alternative Products `a.css-r7o3yn-itemTitle > div.css-1m6aaa5-flexWrapper > div.css-1unxnfm-imageHeight > img.css-15lg9ru-imgResponsive`	/deepweb/assets/sigmaaldrich/marketing/global/images/home...

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

●Layout shift culprits

●Optimize DOM size

●Modern HTTP

●Optimize viewport for mobile

●User Timing marks and measures 36 user timings

●Avoid long main-thread tasks 20 long tasks found

●Avoid non-composited animations 1 animated element found

●Network Requests

●Network Round Trip Times 60 ms

●Server Backend Latencies 150 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid large layout shifts 3 layout shifts found

○INP breakdown

Accessibility

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

ARIA

Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn how to match ARIA attributes to their roles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Clear Search `div.css-j84rqn-searchWrapper > div.css-1vwaa72-root > div.css-fttdx6-autoSuggestInputWrapper > div.MuiInputBase-root`

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
Products `div.css-1vwaa72-root > div.css-fttdx6-autoSuggestInputWrapper > div.MuiInputBase-root > div.MuiSelect-select`

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.

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
Top Deals `div.MuiContainer-root > div.css-1lgx5g-content-productHeroCardContent > div.css-zb6ojd-titleHeader > h3.MuiTypography-root`

These are opportunities to improve keyboard navigation in your application.

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
Cart 0 `nav.css-1hzsbo3-headerBottomNavWrapper > div.css-aqt99m-headerBottomRightNav > div.css-rvpxz5-navRightCart > button#show-mini-cart-menu-button-desktop`
Privacy Policy `div#onetrust-group-container > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link`

○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-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

●`[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

●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.

●Links have a discernible name

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Image elements do not have `[alt]` attributes that are redundant text.

●Identical links have the same purpose.

○`[accesskey]` values are unique

○`button`, `link`, and `menuitem` elements 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

○Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

○List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

○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

○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

User Experience

Image display dimensions should match natural aspect ratio. Learn more about image aspect ratio.

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Aspect Ratio (Displayed)	Aspect Ratio (Actual)
Sigma-Aldrich `a#product-card-70850MM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/assets/images/sigmaaldrich-no-image/sigmaaldrich-no-imag...	112 x 50 (2.24)	640 x 640 (1.00)
Trifluoroacetic acid ReagentPlus®, 99% `a#product-card-T6508SIGALD-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/180/762/6...	112 x 50 (2.24)	640 x 407 (1.57)
Sodium cyanide EMPLURA® `a#product-card-1.06437MM-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/416/076/53566...	112 x 50 (2.24)	640 x 349 (1.83)
Hydrochloric Acid 31.5-35.5% `a#product-card-HX0603SMM-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/546/395/1...	112 x 50 (2.24)	640 x 321 (1.99)
SARS-CoV-2 Receptor Binding Domain Spike protein RBD recombinant, expressed in … `a#product-card-SAE1000SIGMA-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/175/261/54fae...	112 x 50 (2.24)	528 x 360 (1.47)
3-Guanidinopropionic acid `a#product-card-G6878SIGMA-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/145/966/f...	112 x 50 (2.24)	640 x 240 (2.67)
Uranium ICP standard traceable to SRM from NIST UO2(NO3)2 in HNO3 2-3% 10 mg/l … `a#product-card-1.70360MM-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/904/460/65c1f...	112 x 50 (2.24)	416 x 360 (1.16)
Milli-Q® EQ 7008/16 Ultrapure Water Purification Kit For Milli-Q® EQ … `a#product-card-EQ70XXPKITMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/203/019/e8a83...	112 x 50 (2.24)	372 x 360 (1.03)
Anti-SEMA5B antibody produced in rabbit Prestige Antibodies® Powered by At… `a#product-card-HPA066548SIGMA-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/455/304/66916...	112 x 50 (2.24)	360 x 360 (1.00)
Dichloromethane `a#product-card-L090000SIGMA-best sellers > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/structures/344/216/e...	112 x 50 (2.24)	640 x 189 (3.39)
Eppendorf® CellXpert® C170i CO2 Incubator Oxygen control, inner door … `a#product-card-EP6731011085SIGMA-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/359/624/25753...	112 x 50 (2.24)	290 x 360 (0.81)
Milli-Q® IX 7010/15 Water Purification Kit For Milli-Q® IX 7010/15 pu… `a#product-card-IX70XXPKITMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/250/970/166fc...	112 x 50 (2.24)	286 x 360 (0.79)
Elix Essential 15 UV Water Purification System `a#product-card-ZLXEV150WWMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/212/741/dee8d...	112 x 50 (2.24)	271 x 360 (0.75)
Elix Essential 10 UV Water Purification System `a#product-card-ZLXEV100WWMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/212/741/dee8d...	112 x 50 (2.24)	271 x 360 (0.75)
Elix Essential 3 UV Water Purification System `a#product-card-ZLXEV030WWMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/212/741/dee8d...	112 x 50 (2.24)	271 x 360 (0.75)
Milli-Q® IQ 7003/05 Ultrapure Water Purification Kit For Milli-Q® IQ … `a#product-card-IQ700XPKITMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/648/225/41e48...	112 x 50 (2.24)	242 x 360 (0.67)
Milli-Q® Polishing Kit for Purified Water For Milli-Q® IQ/EQ 7000 ult… `a#product-card-IPAKKIT00MM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/122/703/8b86d...	112 x 50 (2.24)	203 x 360 (0.56)
Milli-Q® IX 7003/05 Water Purification Kit For Milli-Q® IX 7003/05 pu… `a#product-card-IX700XPKITMM-new arrivals > div.css-1ppc2cz-mainContent > div.css-giazc0-mainContentImage > img.css-6zqear-image`	/deepweb/assets/sigmaaldrich/product/images/364/105/6569a...	112 x 50 (2.24)	166 x 360 (0.46)

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
AttributionReporting	www.sigmaaldrich.com/ruxitagentjs_ICA15789NPRTUVXfhqrux_10335260306043831.js line 251, col 106

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

Source	Description
	`An unknown error occurred when fetching the script.`
www.sigmaaldrich.com/US/en	`TypeError: Failed to register a ServiceWorker for scope ('https://www.sigmaaldrich.com/') with script ('https://www.sigmaaldrich.com/sw.8a062.js'): An unknown error occurred when fetching the script.`

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.

●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

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

○Use a strong HSTS policy

○Mitigate clickjacking with XFO or CSP

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 destination	Link Text
/US/en/products/molecular-biology-and-functional-genomics...	Learn More
www.sigmaaldrich.com/US/en/campaigns/new-popular-products	Learn More
www.sigmaaldrich.com/US/en/services/recycler-solvent-systems	Learn More

Format your HTML in a way that enables crawlers to better understand your app’s content.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
Cookie Settings `div.css-82kwju-GlobalFooter-legal > div.css-15zsyhh-GlobalFooter-trademarkSubhead > div.css-g4gv62-GlobalFooter-trademarkSubheadLinks > a.ot-sdk-show-settings`
div.MuiPaper-root > ul.MuiList-root > div.MuiBox-root > a.MuiTypography-root `div.MuiPaper-root > ul.MuiList-root > div.MuiBox-root > a.MuiTypography-root`

If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more about robots.txt.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

○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

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`