Tools & Wizards About Us
chemlearn.de screenshot

Report Summary

  • 0

    Performance

  • 33

    Accessibility

    Visual factors better than
    that of 18% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    36% of websites

  • 58

    SEO

    Google-friendlier than
    20% of websites

chemlearn.de

Chemlearn

Page Load Speed

5.1 sec in total

First Response

399 ms

Resources Loaded

4.6 sec

Page Rendered

154 ms

chemlearn.de screenshot

About Website

Visit chemlearn.de now to see the best up-to-date Chemlearn content and also check out these interesting facts you probably never knew about chemlearn.de

Visit chemlearn.de

Key Findings

We analyzed Chemlearn.de page load time and found that the first response time was 399 ms and then it took 4.7 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

chemlearn.de performance score

0

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value0

0/100

10%

LCP (Largest Contentful Paint)

Value0

0/100

25%

SI (Speed Index)

Value0

0/100

10%

TBT (Total Blocking Time)

Value0

0/100

30%

CLS (Cumulative Layout Shift)

Value0.001

100/100

15%

TTI (Time to Interactive)

Value0

0/100

10%

Network Requests Diagram

chemlearn.de

399 ms

chemie-lernen.npage.de

795 ms

style.css

180 ms

main.css

270 ms

jquery-ui-1.11.4.custom.min.css

185 ms

Our browser made a total of 65 requests to load all elements on the main page. We found that 2% of them (1 request) were addressed to the original Chemlearn.de, 38% (25 requests) were made to Imgserv.sponsorads.de and 29% (19 requests) were made to Chemie-lernen.npage.de. The less responsive or slowest element that took the longest time to load (795 ms) relates to the external source Chemie-lernen.npage.de.

Page Optimization Overview & Recommendations

Page size can be reduced by 302.9 kB (47%)

Content Size

640.7 kB

After Optimization

337.8 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Chemlearn.de main page is 640.7 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. 30% of websites need less resources to load. Javascripts take 436.6 kB which makes up the majority of the site volume.

HTML Optimization

-46%

Potential reduce by 333 B

  • Original 725 B
  • After minification 698 B
  • After compression 392 B

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 333 B or 46% of the original size.

Image Optimization

-1%

Potential reduce by 1.2 kB

  • Original 147.5 kB
  • After minification 146.3 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. Chemlearn images are well optimized though.

JavaScript Optimization

-59%

Potential reduce by 256.1 kB

  • Original 436.6 kB
  • After minification 433.9 kB
  • After compression 180.6 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 256.1 kB or 59% of the original size.

CSS Optimization

-81%

Potential reduce by 45.3 kB

  • Original 55.9 kB
  • After minification 49.0 kB
  • After compression 10.5 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. Chemlearn.de needs all CSS files to be minified and compressed as it can save up to 45.3 kB or 81% of the original size.

Requests Breakdown

Number of requests can be reduced by 29 (46%)

Requests Now

63

After Optimization

34

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 63 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Chemlearn. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 17 to 1 for JavaScripts and from 6 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

chemlearn.de

chemlearn.de

399 ms

chemie-lernen.npage.de

chemie-lernen.npage.de

795 ms

style.css

style.css

180 ms

main.css

main.css

270 ms

jquery-ui-1.11.4.custom.min.css

jquery-ui-1.11.4.custom.min.css

185 ms

jquery-1.10.2.min.js

jquery-1.10.2.min.js

449 ms

jquery.i18n.min.js

jquery.i18n.min.js

188 ms

setLocalizations.js

setLocalizations.js

265 ms

jquery-ui-1.11.4.min.js

jquery-ui-1.11.4.min.js

695 ms

main_functions.js

main_functions.js

273 ms

js_s2.js

js_s2.js

280 ms

cookieconsent.latest.min.js

cookieconsent.latest.min.js

353 ms

ownerCheck.js

ownerCheck.js

355 ms

adsbygoogle.js

adsbygoogle.js

7 ms

count.js

count.js

291 ms

186 ms

webfonts.source.css

webfonts.source.css

96 ms

chemie1.gif

chemie1.gif

277 ms

bg.gif

bg.gif

94 ms

header.jpg

header.jpg

88 ms

page.jpg

page.jpg

93 ms

ajs.php

ajs.php

472 ms

show_ads.js

show_ads.js

3 ms

lg.php

lg.php

156 ms

zrt_lookup.html

zrt_lookup.html

37 ms

show_ads_impl.js

show_ads_impl.js

41 ms

ads

ads

126 ms

osd.js

osd.js

53 ms

ads

ads

182 ms

footer.jpg

footer.jpg

93 ms

delivery.php

delivery.php

448 ms

script.php

script.php

280 ms

a_script.php

a_script.php

125 ms

menu-0.gif

menu-0.gif

199 ms

menu-1.gif

menu-1.gif

197 ms

menu-2.gif

menu-2.gif

202 ms

menu-3.gif

menu-3.gif

201 ms

menu-4.gif

menu-4.gif

199 ms

menu-5.gif

menu-5.gif

200 ms

menu-6.gif

menu-6.gif

293 ms

menu-0h.gif

menu-0h.gif

296 ms

menu-1h.gif

menu-1h.gif

297 ms

menu-2h.gif

menu-2h.gif

298 ms

menu-3h.gif

menu-3h.gif

299 ms

menu-4h.gif

menu-4h.gif

298 ms

menu-5h.gif

menu-5h.gif

388 ms

menu-6h.gif

menu-6h.gif

394 ms

abpc.js

abpc.js

166 ms

rotate.php

rotate.php

122 ms

light-bottom.custom.css

light-bottom.custom.css

94 ms

ikariam_dez2015_01.jpg

ikariam_dez2015_01.jpg

366 ms

light-bottom.css

light-bottom.css

92 ms

avw.php

avw.php

162 ms

cookie-consent-logo.png

cookie-consent-logo.png

346 ms

corner-tl.gif

corner-tl.gif

100 ms

top.gif

top.gif

100 ms

tab-right.gif

tab-right.gif

102 ms

tab-left.gif

tab-left.gif

98 ms

menu.gif

menu.gif

101 ms

corner-tr.gif

corner-tr.gif

101 ms

left.gif

left.gif

197 ms

right.gif

right.gif

197 ms

corner-bl.gif

corner-bl.gif

199 ms

footer.gif

footer.gif

201 ms

corner-br.gif

corner-br.gif

200 ms

Accessibility Review

chemlearn.de accessibility score

33

Accessibility Issues

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

<frame> or <iframe> elements do not have a title

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

Best Practices

chemlearn.de best practices score

75

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

Low

Ensure CSP is effective against XSS attacks

General

Impact

Issue

High

Browser errors were logged to the console

High

Page has valid source maps

SEO Factors

chemlearn.de SEO score

58

Search Engine Optimization Advices

Crawling and Indexing

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

Impact

Issue

High

robots.txt is not valid

Language and Encoding

  • Language Detected

    N/A

  • Language Claimed

    N/A

  • Encoding

    ISO-8859-15

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Chemlearn.de can be misinterpreted by Google and other search engines. Unfortunately we cannot identify language used on the page (probably there is a mix of languages, too little text or something else) and no language is claimed in <html> or <meta> tags either. Our system also found out that Chemlearn.de main page’s claimed encoding is iso-8859-15. 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

chemlearn.de

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