Report Summary

  • 18

    Performance

    Renders faster than
    34% of other websites

  • 91

    Accessibility

    Visual factors better than
    that of 78% of websites

  • 58

    Best Practices

    More advanced features
    available than in
    19% of websites

  • 77

    SEO

    Google-friendlier than
    36% of websites

dobre-knihy.cz

Všechny Dobré knihy na jednom místě - 90.000 titulů skladem

Page Load Speed

4.5 sec in total

First Response

359 ms

Resources Loaded

3.8 sec

Page Rendered

288 ms

dobre-knihy.cz screenshot

About Website

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

Kniha,knihy i knižní novinky v online knihkupectví Dobré Knihy. Dobré knihy a levné knihy i knižní novinky v našem knihkupectví online.

Visit dobre-knihy.cz

Key Findings

We analyzed Dobre-knihy.cz page load time and found that the first response time was 359 ms and then it took 4.1 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

dobre-knihy.cz performance score

18

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value7.1 s

1/100

10%

LCP (Largest Contentful Paint)

Value9.2 s

1/100

25%

SI (Speed Index)

Value10.9 s

6/100

10%

TBT (Total Blocking Time)

Value2,250 ms

6/100

30%

CLS (Cumulative Layout Shift)

Value0.013

100/100

15%

TTI (Time to Interactive)

Value16.9 s

5/100

10%

Network Requests Diagram

dobre-knihy.cz

359 ms

www.dobre-knihy.cz

948 ms

_combined.min.css

661 ms

_combined.min.js

546 ms

all.js

7 ms

Our browser made a total of 91 requests to load all elements on the main page. We found that 2% of them (2 requests) were addressed to the original Dobre-knihy.cz, 43% (39 requests) were made to Pimages.dcdn.cz and 27% (25 requests) were made to Dk.dcdn.cz. The less responsive or slowest element that took the longest time to load (1.5 sec) relates to the external source C.imedia.cz.

Page Optimization Overview & Recommendations

Page size can be reduced by 1.2 MB (48%)

Content Size

2.4 MB

After Optimization

1.3 MB

In fact, the total size of Dobre-knihy.cz main page is 2.4 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. 55% of websites need less resources to load. CSS take 1.0 MB which makes up the majority of the site volume.

HTML Optimization

-86%

Potential reduce by 96.1 kB

  • Original 111.8 kB
  • After minification 107.4 kB
  • After compression 15.7 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 96.1 kB or 86% of the original size.

Image Optimization

-7%

Potential reduce by 40.4 kB

  • Original 560.7 kB
  • After minification 520.3 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. Dobre Knihy images are well optimized though.

JavaScript Optimization

-72%

Potential reduce by 538.8 kB

  • Original 752.5 kB
  • After minification 752.5 kB
  • After compression 213.7 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 538.8 kB or 72% of the original size.

CSS Optimization

-48%

Potential reduce by 488.9 kB

  • Original 1.0 MB
  • After minification 1.0 MB
  • After compression 529.2 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. Dobre-knihy.cz needs all CSS files to be minified and compressed as it can save up to 488.9 kB or 48% of the original size.

Requests Breakdown

Number of requests can be reduced by 22 (25%)

Requests Now

87

After Optimization

65

The browser has sent 87 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Dobre Knihy. 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 as a result speed up the page load time.

Accessibility Review

dobre-knihy.cz accessibility score

91

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

High

Links do not have a discernible name

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

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

dobre-knihy.cz best practices score

58

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

Displays images with incorrect aspect ratio

High

Serves images with low resolution

General

Impact

Issue

Low

Detected JavaScript libraries

High

Browser errors were logged to the console

High

Missing source maps for large first-party JavaScript

SEO Factors

dobre-knihy.cz SEO score

77

Search Engine Optimization Advices

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 Dobre-knihy.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 Dobre-knihy.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

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