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cern.ch screenshot

Report Summary

  • 13

    Performance

    Renders faster than
    25% of other websites

  • 94

    Accessibility

    Visual factors better than
    that of 83% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    55% of websites

  • 93

    SEO

    Google-friendlier than
    83% of websites

cern.ch

Home | CERN

Page Load Speed

4.8 sec in total

First Response

295 ms

Resources Loaded

4 sec

Page Rendered

531 ms

cern.ch screenshot

About Website

Welcome to cern.ch homepage info - get ready to check CERN best content for United States right away, or after learning these important things about cern.ch

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Univer...

Visit cern.ch

Key Findings

We analyzed Cern.ch page load time and found that the first response time was 295 ms and then it took 4.5 sec to load all DOM resources and completely render a web page. This is a poor result, as 70% of websites can load faster.

Performance Metrics

cern.ch performance score

13

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value5.3 s

7/100

10%

LCP (Largest Contentful Paint)

Value37.8 s

0/100

25%

SI (Speed Index)

Value11.3 s

5/100

10%

TBT (Total Blocking Time)

Value950 ms

29/100

30%

CLS (Cumulative Layout Shift)

Value0.692

7/100

15%

TTI (Time to Interactive)

Value11.5 s

18/100

10%

Network Requests Diagram

cern.ch

295 ms

home.cern

643 ms

matomo.js

770 ms

cern_loading.css

195 ms

owl.carousel.css

582 ms

Our browser made a total of 162 requests to load all elements on the main page. We found that 1% of them (1 request) were addressed to the original Cern.ch, 86% (140 requests) were made to Home.cern and 10% (16 requests) were made to Framework.web.cern.ch. The less responsive or slowest element that took the longest time to load (1.9 sec) relates to the external source Framework.web.cern.ch.

Page Optimization Overview & Recommendations

Page size can be reduced by 355.5 kB (9%)

Content Size

4.2 MB

After Optimization

3.8 MB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Cern.ch main page is 4.2 MB. This result falls beyond the top 1M of websites and identifies a large and not optimized web page that may take ages to load. 65% of websites need less resources to load. Images take 3.6 MB which makes up the majority of the site volume.

HTML Optimization

-90%

Potential reduce by 140.6 kB

  • Original 156.3 kB
  • After minification 104.5 kB
  • After compression 15.7 kB

HTML content can be minified and compressed by a website’s server. The most efficient way is to compress content using GZIP which reduces data amount travelling through the network between server and browser. This page needs HTML code to be minified as it can gain 51.8 kB, which is 33% of the original size. It is highly recommended that content of this web page should be compressed using GZIP, as it can save up to 140.6 kB or 90% of the original size.

Image Optimization

-5%

Potential reduce by 167.9 kB

  • Original 3.6 MB
  • After minification 3.4 MB

Image size optimization can help to speed up a website loading time. The chart above shows the difference between the size before and after optimization. CERN images are well optimized though.

JavaScript Optimization

-8%

Potential reduce by 23.1 kB

  • Original 276.3 kB
  • After minification 274.7 kB
  • After compression 253.2 kB

It’s better to minify JavaScript in order to improve website performance. The diagram shows the current total size of all JavaScript files against the prospective JavaScript size after its minification and compression. This website has mostly compressed JavaScripts.

CSS Optimization

-23%

Potential reduce by 23.9 kB

  • Original 104.9 kB
  • After minification 100.8 kB
  • After compression 81.0 kB

CSS files minification is very important to reduce a web page rendering time. The faster CSS files can load, the earlier a page can be rendered. Cern.ch needs all CSS files to be minified and compressed as it can save up to 23.9 kB or 23% of the original size.

Requests Breakdown

Number of requests can be reduced by 121 (80%)

Requests Now

151

After Optimization

30

  • Images
  • JavaScript
  • CSS

The browser has sent 151 CSS, Javascripts, AJAX and image requests in order to completely render the main page of CERN. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 55 to 1 for JavaScripts and from 68 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

cern.ch

cern.ch

295 ms

home.cern

home.cern

643 ms

matomo.js

matomo.js

770 ms

cern_loading.css

cern_loading.css

195 ms

owl.carousel.css

owl.carousel.css

582 ms

owl.theme.default.css

owl.theme.default.css

679 ms

featured-banner.css

featured-banner.css

298 ms

align.module.css

align.module.css

295 ms

fieldgroup.module.css

fieldgroup.module.css

296 ms

container-inline.module.css

container-inline.module.css

311 ms

clearfix.module.css

clearfix.module.css

298 ms

details.module.css

details.module.css

297 ms

hidden.module.css

hidden.module.css

404 ms

item-list.module.css

item-list.module.css

398 ms

js.module.css

js.module.css

400 ms

nowrap.module.css

nowrap.module.css

399 ms

position-container.module.css

position-container.module.css

402 ms

progress.module.css

progress.module.css

412 ms

reset-appearance.module.css

reset-appearance.module.css

506 ms

resize.module.css

resize.module.css

506 ms

sticky-header.module.css

sticky-header.module.css

504 ms

system-status-counter.css

system-status-counter.css

507 ms

system-status-report-counters.css

system-status-report-counters.css

506 ms

system-status-report-general-info.css

system-status-report-general-info.css

520 ms

tablesort.module.css

tablesort.module.css

608 ms

tree-child.module.css

tree-child.module.css

607 ms

page-navigation.component.css

page-navigation.component.css

606 ms

row.component.css

row.component.css

608 ms

margin.component.css

margin.component.css

608 ms

component-preview-card.css

component-preview-card.css

621 ms

background.component.css

background.component.css

709 ms

views.module.css

views.module.css

708 ms

agenda-box.component.css

agenda-box.component.css

710 ms

media.component.css

media.component.css

712 ms

header_blocks.css

header_blocks.css

713 ms

header-component.css

header-component.css

722 ms

screen.css

screen.css

809 ms

cookieconsent.css

cookieconsent.css

810 ms

menu.component.css

menu.component.css

822 ms

onecol.css

onecol.css

813 ms

prism.css

prism.css

776 ms

colorbox.css

colorbox.css

873 ms

prism.js

prism.js

1913 ms

jquery.colorbox-min.js

jquery.colorbox-min.js

786 ms

ScrollMagic.min.js

ScrollMagic.min.js

787 ms

text-effects.js

text-effects.js

785 ms

owl.carousel.js

owl.carousel.js

881 ms

owl.carousel2.thumbs.js

owl.carousel2.thumbs.js

879 ms

paragraphs.unpublished.css

paragraphs.unpublished.css

723 ms

colors.css

colors.css

640 ms

base.css

base.css

724 ms

layout.css

layout.css

621 ms

footer.css

footer.css

624 ms

header.css

header.css

629 ms

pagination.css

pagination.css

633 ms

forms.css

forms.css

624 ms

fields.css

fields.css

626 ms

dropdown.css

dropdown.css

638 ms

progress.css

progress.css

637 ms

accordion.css

accordion.css

628 ms

social-sharing.css

social-sharing.css

635 ms

theme.css

theme.css

708 ms

cookies.css

cookies.css

617 ms

viewspage.css

viewspage.css

628 ms

faq-views.css

faq-views.css

636 ms

agenda-views.css

agenda-views.css

634 ms

news-views.css

news-views.css

636 ms

stories-views.css

stories-views.css

702 ms

resources-views.css

resources-views.css

616 ms

taxonomies-views.css

taxonomies-views.css

628 ms

search-views.css

search-views.css

632 ms

common-views.css

common-views.css

632 ms

generic-views.css

generic-views.css

633 ms

layout.css

layout.css

736 ms

overrides.css

overrides.css

613 ms

header.css

header.css

649 ms

views.css

views.css

627 ms

blocks.css

blocks.css

627 ms

jquery.min.js

jquery.min.js

762 ms

underscore-min.js

underscore-min.js

710 ms

matomo.php

matomo.php

168 ms

once.min.js

once.min.js

629 ms

drupalSettingsLoader.js

drupalSettingsLoader.js

629 ms

drupal.js

drupal.js

645 ms

drupal.init.js

drupal.init.js

642 ms

index.umd.min.js

index.umd.min.js

702 ms

cern_loading.js

cern_loading.js

720 ms

config.js

config.js

638 ms

MathJax.js

MathJax.js

682 ms

setup.js

setup.js

647 ms

matomo.js

matomo.js

663 ms

progress.js

progress.js

722 ms

progress.js

progress.js

677 ms

loadjs.min.js

loadjs.min.js

677 ms

debounce.js

debounce.js

671 ms

announce.js

announce.js

667 ms

message.js

message.js

668 ms

message.js

message.js

710 ms

ajax.js

ajax.js

733 ms

ajax.js

ajax.js

638 ms

cernbase.js

cernbase.js

639 ms

social-sharing.js

social-sharing.js

656 ms

footer.js

footer.js

660 ms

agenda-views.js

agenda-views.js

690 ms

faq-views.js

faq-views.js

642 ms

news-views.js

news-views.js

653 ms

resources-views.js

resources-views.js

663 ms

stories-views.js

stories-views.js

666 ms

search-views.js

search-views.js

711 ms

common-views.js

common-views.js

645 ms

box-effects.js

box-effects.js

639 ms

views_carousel.js

views_carousel.js

658 ms

file

file

589 ms

file

file

503 ms

anchor-fix.js

anchor-fix.js

955 ms

bootstrap.min.js

bootstrap.min.js

908 ms

regular.woff

regular.woff

217 ms

bold.woff

bold.woff

192 ms

cern.woff

cern.woff

217 ms

semibold.woff

semibold.woff

217 ms

light.woff

light.woff

217 ms

bold.woff

bold.woff

289 ms

drupal.bootstrap.js

drupal.bootstrap.js

910 ms

attributes.js

attributes.js

906 ms

theme.js

theme.js

906 ms

popover.js

popover.js

888 ms

tooltip.js

tooltip.js

889 ms

page-navigation.component.js

page-navigation.component.js

857 ms

row.component.js

row.component.js

824 ms

component-preview-card.js

component-preview-card.js

803 ms

background.js

background.js

804 ms

component-media.js

component-media.js

789 ms

featured-banner.js

featured-banner.js

767 ms

header_carousel.js

header_carousel.js

760 ms

cern_toolbar.js

cern_toolbar.js

663 ms

menu.component.js

menu.component.js

663 ms

cern-logo.png

cern-logo.png

686 ms

1209226_01-A5-at-72-dpi.jpg

1209226_01-A5-at-72-dpi.jpg

807 ms

Cern70logo_0.png

Cern70logo_0.png

714 ms

loader.gif

loader.gif

1136 ms

arrow-blue.png

arrow-blue.png

657 ms

202108-102_004.jpeg

202108-102_004.jpeg

716 ms

CollideCopenhagen_Bucknell_1920x1080.jpeg

CollideCopenhagen_Bucknell_1920x1080.jpeg

644 ms

MA2_9709.jpeg

MA2_9709.jpeg

672 ms

ALICE%20focal%20and%20its3%20final.jpg

ALICE%20focal%20and%20its3%20final.jpg

714 ms

Picture1.png

Picture1.png

874 ms

SHiP-experiment-labelled.jpg

SHiP-experiment-labelled.jpg

1096 ms

gammagamma_run194108_evt564224000_ispy_3d-annotated-2.png

gammagamma_run194108_evt564224000_ispy_3d-annotated-2.png

902 ms

CERN%20Thumbnails%20%282%29.jpg

CERN%20Thumbnails%20%282%29.jpg

732 ms

8704168-Icon.jpg

8704168-Icon.jpg

633 ms

201811-329_15.jpeg

201811-329_15.jpeg

722 ms

6910413-min_0_2.jpg

6910413-min_0_2.jpg

1089 ms

202310-230_50_2_0.jpg

202310-230_50_2_0.jpg

1169 ms

Screenshot-vitual-tour.jpg

Screenshot-vitual-tour.jpg

856 ms

Artist%20Rasheedah%20Phillips%20from%20Black%20Quantum%20Futurism%20with%20theoretical%20physicist%20Dorota%20Grabowska_1.jpg

Artist%20Rasheedah%20Phillips%20from%20Black%20Quantum%20Futurism%20with%20theoretical%20physicist%20Dorota%20Grabowska_1.jpg

998 ms

OPEN-PHO-CIVIL-2023-001-6_0_0.jpeg

OPEN-PHO-CIVIL-2023-001-6_0_0.jpeg

935 ms

CERN-EX-1212264-01_0_0.jpg

CERN-EX-1212264-01_0_0.jpg

940 ms

CERN-PHOTO-201609-254-24-large.jpg

CERN-PHOTO-201609-254-24-large.jpg

675 ms

ATLAS-PHO-EVENTS-2014-010-1.jpg

ATLAS-PHO-EVENTS-2014-010-1.jpg

697 ms

CERN-AC-0911188-01.jpg

CERN-AC-0911188-01.jpg

705 ms

CERN-EX-23296-1.jpg

CERN-EX-23296-1.jpg

719 ms

CERN-GE-9407011-31.jpg

CERN-GE-9407011-31.jpg

749 ms

Accessibility Review

cern.ch accessibility score

94

Accessibility Issues

Contrast

These are opportunities to improve the legibility of your content.

Impact

Issue

High

Background and foreground colors do not have a sufficient contrast ratio.

Navigation

These are opportunities to improve keyboard navigation in your application.

Impact

Issue

High

Heading elements are not in a sequentially-descending order

Names and labels

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.

Impact

Issue

High

Links do not have a discernible name

Best Practices

cern.ch best practices score

83

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

Low

Ensure CSP is effective against XSS attacks

General

Impact

Issue

Low

Detected JavaScript libraries

High

Browser errors were logged to the console

High

Page has valid source maps

SEO Factors

cern.ch SEO score

93

Search Engine Optimization Advices

Crawling and Indexing

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

Impact

Issue

High

Links are not crawlable

Mobile Friendly

Make sure your pages are mobile friendly so users don’t have to pinch or zoom in order to read the content pages. [Learn more](https://developers.google.com/search/mobile-sites/).

Impact

Issue

High

Document uses legible font sizes

Language and Encoding

  • Language Detected

    EN

  • Language Claimed

    EN

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Cern.ch can be misinterpreted by Google and other search engines. Our service has detected that English is used on the page, and it matches the claimed language. Our system also found out that Cern.ch main page’s claimed encoding is utf-8. Use of this encoding format is the best practice as the main page visitors from all over the world won’t have any issues with symbol transcription.

Social Sharing Optimization

cern.ch

Open Graph description is not detected on the main page of CERN. Lack of Open Graph description can be counter-productive for their social media presence, as such a description allows converting a website homepage (or other pages) into good-looking, rich and well-structured posts, when it is being shared on Facebook and other social media. For example, adding the following code snippet into HTML <head> tag will help to represent this web page correctly in social networks: