Report Summary

  • 38

    Performance

    Renders faster than
    59% of other websites

  • 96

    Accessibility

    Visual factors better than
    that of 90% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    57% of websites

  • 89

    SEO

    Google-friendlier than
    67% of websites

co2-rechner.de

CO2-Rechner des Umweltbundesamtes

Page Load Speed

3.8 sec in total

First Response

382 ms

Resources Loaded

2.9 sec

Page Rendered

492 ms

co2-rechner.de screenshot

About Website

Welcome to co2-rechner.de homepage info - get ready to check CO2 Rechner best content for Germany right away, or after learning these important things about co2-rechner.de

CO2-Rechner von klimAktiv

Visit co2-rechner.de

Key Findings

We analyzed Co2-rechner.de page load time and found that the first response time was 382 ms and then it took 3.4 sec to load all DOM resources and completely render a web page. This is a poor result, as 55% of websites can load faster.

Performance Metrics

co2-rechner.de performance score

38

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.8 s

27/100

10%

LCP (Largest Contentful Paint)

Value10.8 s

0/100

25%

SI (Speed Index)

Value6.7 s

36/100

10%

TBT (Total Blocking Time)

Value120 ms

97/100

30%

CLS (Cumulative Layout Shift)

Value0.981

2/100

15%

TTI (Time to Interactive)

Value10.6 s

23/100

10%

Network Requests Diagram

co2-rechner.de

382 ms

332 ms

bootstrap.min.css

586 ms

bootstrap-slider.css

296 ms

font-awesome.min.css

303 ms

Our browser made a total of 35 requests to load all elements on the main page. We found that 3% of them (1 request) were addressed to the original Co2-rechner.de, 94% (33 requests) were made to Uba.co2-rechner.de and 3% (1 request) were made to Piwik.klimaktiv.de. The less responsive or slowest element that took the longest time to load (904 ms) relates to the external source Uba.co2-rechner.de.

Page Optimization Overview & Recommendations

Page size can be reduced by 641.0 kB (74%)

Content Size

861.0 kB

After Optimization

220.0 kB

In fact, the total size of Co2-rechner.de main page is 861.0 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. 45% of websites need less resources to load. Javascripts take 562.0 kB which makes up the majority of the site volume.

HTML Optimization

-77%

Potential reduce by 65.1 kB

  • Original 84.7 kB
  • After minification 77.3 kB
  • After compression 19.6 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 65.1 kB or 77% of the original size.

Image Optimization

-10%

Potential reduce by 1.0 kB

  • Original 10.2 kB
  • After minification 9.2 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. CO2 Rechner images are well optimized though.

JavaScript Optimization

-71%

Potential reduce by 400.8 kB

  • Original 562.0 kB
  • After minification 531.9 kB
  • After compression 161.1 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 400.8 kB or 71% of the original size.

CSS Optimization

-85%

Potential reduce by 174.1 kB

  • Original 204.2 kB
  • After minification 203.3 kB
  • After compression 30.1 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. Co2-rechner.de needs all CSS files to be minified and compressed as it can save up to 174.1 kB or 85% of the original size.

Requests Breakdown

Number of requests can be reduced by 18 (60%)

Requests Now

30

After Optimization

12

The browser has sent 30 CSS, Javascripts, AJAX and image requests in order to completely render the main page of CO2 Rechner. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 14 to 1 for JavaScripts and from 6 to 1 for CSS and as a result speed up the page load time.

Accessibility Review

co2-rechner.de accessibility score

96

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

[id] attributes on active, focusable elements are not unique

Best Practices

co2-rechner.de best practices score

83

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

General

Impact

Issue

Low

Detected JavaScript libraries

High

Page has valid source maps

SEO Factors

co2-rechner.de SEO score

89

Search Engine Optimization Advices

Content Best Practices

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

Impact

Issue

High

Links do not have descriptive text

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

    DE

  • Language Claimed

    DE

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Co2-rechner.de can be misinterpreted by Google and other search engines. Our service has detected that German is used on the page, and it matches the claimed language. Our system also found out that Co2-rechner.de 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

Open Graph description is not detected on the main page of CO2 Rechner. 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: