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web.cern.ch screenshot

Report Summary

  • 67

    Performance

    Renders faster than
    80% of other websites

  • 62

    Accessibility

    Visual factors better than
    that of 28% of websites

  • 67

    Best Practices

    More advanced features
    available than in
    24% of websites

  • 71

    SEO

    Google-friendlier than
    30% of websites

web.cern.ch

CERN Web Services

Page Load Speed

4.5 sec in total

First Response

278 ms

Resources Loaded

4.1 sec

Page Rendered

139 ms

web.cern.ch screenshot

About Website

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

Visit web.cern.ch

Key Findings

We analyzed Web.cern.ch page load time and found that the first response time was 278 ms and then it took 4.2 sec to load all DOM resources and completely render a web page. This is a poor result, as 65% of websites can load faster.

Performance Metrics

web.cern.ch performance score

67

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.2 s

42/100

10%

LCP (Largest Contentful Paint)

Value3.4 s

67/100

25%

SI (Speed Index)

Value5.4 s

57/100

10%

TBT (Total Blocking Time)

Value20 ms

100/100

30%

CLS (Cumulative Layout Shift)

Value0.496

16/100

15%

TTI (Time to Interactive)

Value4.4 s

83/100

10%

Network Requests Diagram

web.cern.ch

278 ms

461 ms

481 ms

787 ms

PTM55Fstylesheet.css

830 ms

Our browser made a total of 39 requests to load all elements on the main page. We found that 3% of them (1 request) were addressed to the original Web.cern.ch, 77% (30 requests) were made to Webservices.web.cern.ch and 13% (5 requests) were made to Framework.web.cern.ch. The less responsive or slowest element that took the longest time to load (848 ms) relates to the external source Framework.web.cern.ch.

Page Optimization Overview & Recommendations

Page size can be reduced by 282.8 kB (70%)

Content Size

406.4 kB

After Optimization

123.6 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Web.cern.ch main page is 406.4 kB. This result falls beyond the top 1M of websites and identifies a large and not optimized web page that may take ages to load. 25% of websites need less resources to load. Javascripts take 274.7 kB which makes up the majority of the site volume.

HTML Optimization

-87%

Potential reduce by 71.9 kB

  • Original 82.9 kB
  • After minification 81.2 kB
  • After compression 11.0 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. HTML code on this page is well minified. It is highly recommended that content of this web page should be compressed using GZIP, as it can save up to 71.9 kB or 87% of the original size.

Image Optimization

-10%

Potential reduce by 2.8 kB

  • Original 27.6 kB
  • After minification 24.8 kB

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. Web CERN images are well optimized though.

JavaScript Optimization

-70%

Potential reduce by 191.8 kB

  • Original 274.7 kB
  • After minification 264.0 kB
  • After compression 82.9 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. It is highly recommended that all JavaScript files should be compressed and minified as it can save up to 191.8 kB or 70% of the original size.

CSS Optimization

-77%

Potential reduce by 16.3 kB

  • Original 21.2 kB
  • After minification 14.1 kB
  • After compression 4.9 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. Web.cern.ch needs all CSS files to be minified and compressed as it can save up to 16.3 kB or 77% of the original size.

Requests Breakdown

Number of requests can be reduced by 24 (73%)

Requests Now

33

After Optimization

9

  • Images
  • JavaScript
  • CSS

The browser has sent 33 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Web 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 7 to 1 for JavaScripts and from 9 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

web.cern.ch

web.cern.ch

278 ms

461 ms

481 ms

787 ms

PTM55Fstylesheet.css

PTM55Fstylesheet.css

830 ms

PTSansWeb.css

PTSansWeb.css

842 ms

PTSerifWeb.css

PTSerifWeb.css

848 ms

toolbar.css

toolbar.css

404 ms

jquery-1.3.2.min.js

jquery-1.3.2.min.js

669 ms

01-CernWeb-General.css

01-CernWeb-General.css

314 ms

02-CernWeb-Header.css

02-CernWeb-Header.css

403 ms

03-CernWeb-OISStyle.css

03-CernWeb-OISStyle.css

402 ms

06-CustomStyle.css

06-CustomStyle.css

320 ms

10-CernWeb-SmallDevices.css

10-CernWeb-SmallDevices.css

409 ms

WebResource.axd

WebResource.axd

411 ms

ScriptResource.axd

ScriptResource.axd

488 ms

ScriptResource.axd

ScriptResource.axd

586 ms

ScriptResource.axd

ScriptResource.axd

497 ms

WebResource.axd

WebResource.axd

418 ms

register-icon.png

register-icon.png

120 ms

triangle.gif

triangle.gif

123 ms

manage.png

manage.png

203 ms

btnSearch.gif

btnSearch.gif

122 ms

WebResource.axd

WebResource.axd

92 ms

WebResource.axd

WebResource.axd

93 ms

WebResource.axd

WebResource.axd

181 ms

WebResource.axd

WebResource.axd

182 ms

WebResource.axd

WebResource.axd

207 ms

WebResource.axd

WebResource.axd

212 ms

WebResource.axd

WebResource.axd

213 ms

cern-logo-large.png

cern-logo-large.png

293 ms

bg-shadow.png

bg-shadow.png

280 ms

rotator.aspx

rotator.aspx

373 ms

PTS55F_W.woff

PTS55F_W.woff

620 ms

PTS75F_W.woff

PTS75F_W.woff

636 ms

bg-shadow-inv.png

bg-shadow-inv.png

254 ms

bullet_go.png

bullet_go.png

255 ms

piwik.js

piwik.js

830 ms

piwik.php

piwik.php

486 ms

Accessibility Review

web.cern.ch accessibility score

62

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.

Internationalization and localization

These are opportunities to improve the interpretation of your content by users in different locales.

Impact

Issue

High

<html> element does not have a [lang] attribute

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

<input type="image"> elements do not have [alt] text

High

Form elements do not have associated labels

High

Links do not have a discernible name

Navigation

These are opportunities to improve keyboard navigation in your application.

Impact

Issue

High

Some elements have a [tabindex] value greater than 0

Best Practices

web.cern.ch best practices score

67

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

High

Includes front-end JavaScript libraries with known security vulnerabilities

Low

Ensure CSP is effective against XSS attacks

User Experience

Impact

Issue

High

Serves images with low resolution

General

Impact

Issue

Low

Detected JavaScript libraries

SEO Factors

web.cern.ch SEO score

71

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

High

Page is blocked from indexing

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

High

Tap targets are not sized appropriately

Language and Encoding

  • Language Detected

    EN

  • Language Claimed

    N/A

  • Encoding

    N/A

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Web.cern.ch can be misinterpreted by Google and other search engines. Our service has detected that English is used on the page, and neither this language nor any other was claimed in <html> or <meta> tags. Our system also found out that Web.cern.ch main page’s claimed encoding is . Changing it to UTF-8 can be a good choice, as this format is commonly used for encoding all over the web and thus their visitors won’t have any troubles with symbol transcription or reading.

Social Sharing Optimization

web.cern.ch

Open Graph description is not detected on the main page of Web 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: