Tools & Wizards About Us
viessmann-us.com screenshot

Report Summary

  • 36

    Performance

    Renders faster than
    56% of other websites

  • 83

    Accessibility

    Visual factors better than
    that of 56% of websites

  • 92

    Best Practices

    More advanced features
    available than in
    81% of websites

  • 85

    SEO

    Google-friendlier than
    56% of websites

viessmann-us.com

Residential & Commercial Heating Solutions | Viessmann US

Page Load Speed

2.3 sec in total

First Response

333 ms

Resources Loaded

1.6 sec

Page Rendered

406 ms

viessmann-us.com screenshot

About Website

Visit viessmann-us.com now to see the best up-to-date Viessmann US content for United States and also check out these interesting facts you probably never knew about viessmann-us.com

Viessmann's comprehensive range of products and services offers individual solutions and efficient systems for all application areas and fuel types.

Visit viessmann-us.com

Key Findings

We analyzed Viessmann-us.com page load time and found that the first response time was 333 ms and then it took 2 sec to load all DOM resources and completely render a web page. This is quite a good result, as only 40% of websites can load faster.

Performance Metrics

viessmann-us.com performance score

36

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value2.8 s

57/100

10%

LCP (Largest Contentful Paint)

Value9.9 s

0/100

25%

SI (Speed Index)

Value6.5 s

39/100

10%

TBT (Total Blocking Time)

Value940 ms

30/100

30%

CLS (Cumulative Layout Shift)

Value0.025

100/100

15%

TTI (Time to Interactive)

Value10.1 s

26/100

10%

Network Requests Diagram

viessmann-us.com

333 ms

www.viessmann-us.com

535 ms

viessmann.base.fonts.latin.min.css

7 ms

viessmann.base.app.min.css

22 ms

global-js-snippet-head.data.js

9 ms

Our browser made a total of 33 requests to load all elements on the main page. We found that 85% of them (28 requests) were addressed to the original Viessmann-us.com, 6% (2 requests) were made to Stats.viessmann.com and 6% (2 requests) were made to Google-analytics.com. The less responsive or slowest element that took the longest time to load (535 ms) belongs to the original domain Viessmann-us.com.

Page Optimization Overview & Recommendations

Page size can be reduced by 854.5 kB (51%)

Content Size

1.7 MB

After Optimization

805.1 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Viessmann-us.com main page is 1.7 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. 45% of websites need less resources to load. Javascripts take 632.6 kB which makes up the majority of the site volume.

HTML Optimization

-82%

Potential reduce by 30.2 kB

  • Original 36.6 kB
  • After minification 31.8 kB
  • After compression 6.4 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 4.8 kB, which is 13% 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 30.2 kB or 82% of the original size.

Image Optimization

-2%

Potential reduce by 7.5 kB

  • Original 486.6 kB
  • After minification 479.1 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. Viessmann US images are well optimized though.

JavaScript Optimization

-70%

Potential reduce by 441.7 kB

  • Original 632.6 kB
  • After minification 623.4 kB
  • After compression 190.9 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 441.7 kB or 70% of the original size.

CSS Optimization

-74%

Potential reduce by 375.0 kB

  • Original 503.7 kB
  • After minification 499.9 kB
  • After compression 128.7 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. Viessmann-us.com needs all CSS files to be minified and compressed as it can save up to 375.0 kB or 74% of the original size.

Requests Breakdown

Number of requests can be reduced by 7 (25%)

Requests Now

28

After Optimization

21

  • Images
  • JavaScript
  • CSS

The browser has sent 28 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Viessmann US. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 8 to 1 for JavaScripts and as a result speed up the page load time.

Network Requests Diagram

viessmann-us.com

viessmann-us.com

333 ms

www.viessmann-us.com

www.viessmann-us.com

535 ms

viessmann.base.fonts.latin.min.css

viessmann.base.fonts.latin.min.css

7 ms

viessmann.base.app.min.css

viessmann.base.app.min.css

22 ms

global-js-snippet-head.data.js

global-js-snippet-head.data.js

9 ms

viessmann.base.lib.modernizr.min.js

viessmann.base.lib.modernizr.min.js

8 ms

viessmann.base.lib.min.js

viessmann.base.lib.min.js

18 ms

viessmann.base.app.min.js

viessmann.base.app.min.js

13 ms

global-js-snippet-body.data.js

global-js-snippet-body.data.js

12 ms

trackingCode.js

trackingCode.js

83 ms

wtid.js

wtid.js

447 ms

analytics.js

analytics.js

14 ms

icon-login.png

icon-login.png

14 ms

viessmann-logo.png

viessmann-logo.png

15 ms

Downloads-XL.jpg

Downloads-XL.jpg

74 ms

vitocrossal_300-cu3a_life_1920x600.jpg

vitocrossal_300-cu3a_life_1920x600.jpg

70 ms

icon-blank-27x27.png

icon-blank-27x27.png

16 ms

Login-Marktpartnerportal.jpg

Login-Marktpartnerportal.jpg

15 ms

company_312x350.jpg

company_312x350.jpg

16 ms

uncompromise_tile.jpg

uncompromise_tile.jpg

67 ms

locator_312x350.jpg

locator_312x350.jpg

68 ms

academy_tile.jpg

academy_tile.jpg

69 ms

incentive_tile_312x350.jpg

incentive_tile_312x350.jpg

74 ms

referenzen.jpg

referenzen.jpg

71 ms

partner_program_312x350.jpg

partner_program_312x350.jpg

72 ms

icon-footer-facebook-xl.png

icon-footer-facebook-xl.png

72 ms

viessmann_logo_footer.png

viessmann_logo_footer.png

74 ms

collect

collect

19 ms

UniversLTW01-55.woff

UniversLTW01-55.woff

312 ms

UniversLTW01-45.woff

UniversLTW01-45.woff

134 ms

UniversLTW01-57.woff

UniversLTW01-57.woff

283 ms

icon-kachel-facebook-xl.png

icon-kachel-facebook-xl.png

52 ms

dcs.gif

dcs.gif

101 ms

Accessibility Review

viessmann-us.com accessibility score

83

Accessibility Issues

ARIA

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.

Impact

Issue

High

[aria-*] attributes do not have valid values

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

Buttons do not have an accessible name

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

Best Practices

viessmann-us.com best practices score

92

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

Page has valid source maps

SEO Factors

viessmann-us.com SEO score

85

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

High

Document doesn't have a valid hreflang

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

    N/A

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Viessmann-us.com 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 Viessmann-us.com 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

viessmann-us.com

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