Tools & Wizards About Us
knihcentrum.cz screenshot

Report Summary

  • 20

    Performance

    Renders faster than
    37% of other websites

  • 88

    Accessibility

    Visual factors better than
    that of 68% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    35% of websites

  • 85

    SEO

    Google-friendlier than
    55% of websites

knihcentrum.cz

KNIHCENTRUM.cz

Page Load Speed

4.6 sec in total

First Response

420 ms

Resources Loaded

3.9 sec

Page Rendered

311 ms

knihcentrum.cz screenshot

About Website

Welcome to knihcentrum.cz homepage info - get ready to check KNIHCENTRUM best content for Czech Republic right away, or after learning these important things about knihcentrum.cz

Přes 70 000 knih skladem. Osobní odběr ZDARMA, nákup nad 999 Kč = DOPRAVA ZDARMA. Rychlé dodání. Věrnostní program.

Visit knihcentrum.cz

Key Findings

We analyzed Knihcentrum.cz page load time and found that the first response time was 420 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

knihcentrum.cz performance score

20

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value4.0 s

22/100

10%

LCP (Largest Contentful Paint)

Value4.7 s

33/100

25%

SI (Speed Index)

Value9.5 s

12/100

10%

TBT (Total Blocking Time)

Value1,080 ms

24/100

30%

CLS (Cumulative Layout Shift)

Value0.809

5/100

15%

TTI (Time to Interactive)

Value16.1 s

6/100

10%

Network Requests Diagram

knihcentrum.cz

420 ms

www.knihcentrum.cz

1114 ms

css

23 ms

styles.css

499 ms

custom.css

361 ms

Our browser made a total of 127 requests to load all elements on the main page. We found that 86% of them (109 requests) were addressed to the original Knihcentrum.cz, 2% (3 requests) were made to Google-analytics.com and 2% (2 requests) were made to C.imedia.cz. The less responsive or slowest element that took the longest time to load (1.2 sec) belongs to the original domain Knihcentrum.cz.

Page Optimization Overview & Recommendations

Page size can be reduced by 963.0 kB (42%)

Content Size

2.3 MB

After Optimization

1.3 MB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Knihcentrum.cz main page is 2.3 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. 60% of websites need less resources to load. Images take 1.1 MB which makes up the majority of the site volume.

HTML Optimization

-83%

Potential reduce by 87.4 kB

  • Original 104.9 kB
  • After minification 83.3 kB
  • After compression 17.5 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 21.6 kB, which is 21% 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 87.4 kB or 83% of the original size.

Image Optimization

-4%

Potential reduce by 48.6 kB

  • Original 1.1 MB
  • After minification 1.0 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. KNIHCENTRUM images are well optimized though.

JavaScript Optimization

-72%

Potential reduce by 494.7 kB

  • Original 688.8 kB
  • After minification 600.3 kB
  • After compression 194.0 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 494.7 kB or 72% of the original size.

CSS Optimization

-85%

Potential reduce by 332.2 kB

  • Original 391.6 kB
  • After minification 324.2 kB
  • After compression 59.4 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. Knihcentrum.cz needs all CSS files to be minified and compressed as it can save up to 332.2 kB or 85% of the original size.

Requests Breakdown

Number of requests can be reduced by 57 (47%)

Requests Now

122

After Optimization

65

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 122 CSS, Javascripts, AJAX and image requests in order to completely render the main page of KNIHCENTRUM. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 35 to 1 for JavaScripts and from 16 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

knihcentrum.cz

knihcentrum.cz

420 ms

www.knihcentrum.cz

www.knihcentrum.cz

1114 ms

css

css

23 ms

styles.css

styles.css

499 ms

custom.css

custom.css

361 ms

noppem.css

noppem.css

504 ms

responsive.css

responsive.css

486 ms

jquery-ui-1.10.0.custom.min.css

jquery-ui-1.10.0.custom.min.css

372 ms

productpromotions.css

productpromotions.css

326 ms

owl.theme.css

owl.theme.css

445 ms

owl.carousel.css

owl.carousel.css

478 ms

iview.css

iview.css

492 ms

style.css

style.css

560 ms

braincategories.css

braincategories.css

588 ms

productvariants.css

productvariants.css

595 ms

watchdog.css

watchdog.css

602 ms

dcmegamenu.css

dcmegamenu.css

620 ms

emailverifier.css

emailverifier.css

611 ms

jquery.min.js

jquery.min.js

29 ms

jquery.unobtrusive-ajax.min.js

jquery.unobtrusive-ajax.min.js

677 ms

jquery.validate.min.js

jquery.validate.min.js

716 ms

jquery.validate.unobtrusive.min.js

jquery.validate.unobtrusive.min.js

724 ms

public.ajaxcart.js

public.ajaxcart.js

718 ms

modernizr.js

modernizr.js

756 ms

personalizedhomepagearea.js

personalizedhomepagearea.js

728 ms

dibuk_ebook.js

dibuk_ebook.js

787 ms

productqualitycatalog.js

productqualitycatalog.js

831 ms

advancedblog.js

advancedblog.js

837 ms

productpromotions.js

productpromotions.js

835 ms

productvariants.js

productvariants.js

843 ms

watchdog.js

watchdog.js

867 ms

jquery.dcmegamenu.1.3.3.min.js

jquery.dcmegamenu.1.3.3.min.js

906 ms

popup-marketing.js

popup-marketing.js

952 ms

advancedcart-flyout.js

advancedcart-flyout.js

954 ms

BrainPerformance.js

BrainPerformance.js

952 ms

brain.search.js

brain.search.js

967 ms

customerverifier.js

customerverifier.js

991 ms

productfilters.js

productfilters.js

1031 ms

jquery-ui-1.10.0.min.js

jquery-ui-1.10.0.min.js

1182 ms

retargeting.js

retargeting.js

396 ms

conversion.js

conversion.js

17 ms

jquery.easytabs.min.js

jquery.easytabs.min.js

871 ms

combined.js

combined.js

918 ms

iview.min.js

iview.min.js

755 ms

owl.carousel.js

owl.carousel.js

752 ms

jquery.hoverIntent.minified.js

jquery.hoverIntent.minified.js

723 ms

jquery.meanmenu.min.js

jquery.meanmenu.min.js

718 ms

public.common.js

public.common.js

185 ms

62928163_rychlovky-a-chutovky-brichace-toma_200.jpg

62928163_rychlovky-a-chutovky-brichace-toma_200.jpg

229 ms

35669280_brichac-tom_200.jpg

35669280_brichac-tom_200.jpg

333 ms

52610257_grey_200.jpg

52610257_grey_200.jpg

344 ms

6914688_sbirka-uloh-z-matematiky-pro-zakladni-skolu_200.jpg

6914688_sbirka-uloh-z-matematiky-pro-zakladni-skolu_200.jpg

333 ms

84361892_ja-jutuber-2_200.jpg

84361892_ja-jutuber-2_200.jpg

345 ms

81164110_abeceda-mzdove-ucetni-2016_200.jpg

81164110_abeceda-mzdove-ucetni-2016_200.jpg

339 ms

77339888_elektronicky-darkovy-poukaz-300-_200.jpg

77339888_elektronicky-darkovy-poukaz-300-_200.jpg

338 ms

83497297_bud-stastny-1_200.jpg

83497297_bud-stastny-1_200.jpg

584 ms

63458915_divka-ve-vlaku_200.jpg

63458915_divka-ve-vlaku_200.jpg

582 ms

77726724_0.jpeg

77726724_0.jpeg

192 ms

89829881_0.jpeg

89829881_0.jpeg

240 ms

shop-roku-2015.jpg

shop-roku-2015.jpg

269 ms

knihcentrum_revue.jpg

knihcentrum_revue.jpg

296 ms

Small-banner-CZ_01.jpg

Small-banner-CZ_01.jpg

301 ms

Small-banner-CZ_02.jpg

Small-banner-CZ_02.jpg

580 ms

action_flag_catalog.png

action_flag_catalog.png

553 ms

bestseller_flag_catalog.png

bestseller_flag_catalog.png

555 ms

hint_flag_catalog.png

hint_flag_catalog.png

558 ms

coming_flag_catalog.png

coming_flag_catalog.png

558 ms

71073916_z-deniku-ajtaka_200.jpg

71073916_z-deniku-ajtaka_200.jpg

578 ms

news_311.jpg

news_311.jpg

576 ms

news_316.jpg

news_316.jpg

576 ms

news_299.JPG

news_299.JPG

576 ms

news_300.jpeg

news_300.jpeg

576 ms

news_301.JPG

news_301.JPG

682 ms

news_314.jpg

news_314.jpg

678 ms

heureka.png

heureka.png

681 ms

gtm.js

gtm.js

72 ms

cart_full_ico.png

cart_full_ico.png

667 ms

KNIHCENTRUM.cz.png

KNIHCENTRUM.cz.png

668 ms

m_glass_low.png

m_glass_low.png

666 ms

bullet-right.gif

bullet-right.gif

770 ms

book.png

book.png

755 ms

star_x_inactive.gif

star_x_inactive.gif

754 ms

star-x-active.gif

star-x-active.gif

757 ms

kosik-maly-modry.png

kosik-maly-modry.png

765 ms

audioCD.png

audioCD.png

765 ms

AjaxLoader.gif

AjaxLoader.gif

861 ms

ga.js

ga.js

34 ms

facebook.png

facebook.png

852 ms

twitter.png

twitter.png

842 ms

google-plus.png

google-plus.png

838 ms

inpage_linkid.js

inpage_linkid.js

10 ms

__utm.gif

__utm.gif

25 ms

youtube.png

youtube.png

800 ms

collect

collect

57 ms

ga-audiences

ga-audiences

34 ms

retargeting

retargeting

190 ms

fbds.js

fbds.js

169 ms

191 ms

ShowPersonalizedProducts

ShowPersonalizedProducts

950 ms

latest

latest

543 ms

sm.js

sm.js

239 ms

alert.png

alert.png

467 ms

cart_ico.png

cart_ico.png

466 ms

88886227_0.jpeg

88886227_0.jpeg

475 ms

88886228_0.jpeg

88886228_0.jpeg

479 ms

87748032_0.jpeg

87748032_0.jpeg

483 ms

87748033_0.jpeg

87748033_0.jpeg

531 ms

88886229_0.jpeg

88886229_0.jpeg

689 ms

88886230_0.jpeg

88886230_0.jpeg

584 ms

88886231_0.jpeg

88886231_0.jpeg

588 ms

88886232_0.jpeg

88886232_0.jpeg

597 ms

98 ms

88886233_0.jpeg

88886233_0.jpeg

754 ms

88886234_0.jpeg

88886234_0.jpeg

682 ms

ui-bg_flat_75_ffffff_40x100.png

ui-bg_flat_75_ffffff_40x100.png

678 ms

21 ms

r.gif

r.gif

222 ms

blog_774.jpg

blog_774.jpg

310 ms

blog_775.jpg

blog_775.jpg

398 ms

blog_776.jpg

blog_776.jpg

398 ms

blog_772.jpg

blog_772.jpg

410 ms

blog_773.jpg

blog_773.jpg

425 ms

blog_771.jpg

blog_771.jpg

467 ms

61838061_trilogie-selekce-box_200.jpg

61838061_trilogie-selekce-box_200.jpg

118 ms

67573177_svet-podle-norma-muze-vyvolat_200.jpg

67573177_svet-podle-norma-muze-vyvolat_200.jpg

120 ms

84361896_mimoni-kdo-je-tady-sef_200.jpg

84361896_mimoni-kdo-je-tady-sef_200.jpg

120 ms

24 ms

Accessibility Review

knihcentrum.cz accessibility score

88

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

Links do not have a discernible name

Best Practices

knihcentrum.cz best practices score

75

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

Browser errors were logged to the console

High

Page has valid source maps

SEO Factors

knihcentrum.cz SEO score

85

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

    CS

  • Language Claimed

    N/A

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Knihcentrum.cz can be misinterpreted by Google and other search engines. Our service has detected that Czech 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 Knihcentrum.cz 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

knihcentrum.cz

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