Report Summary

  • 52

    Performance

    Renders faster than
    69% of other websites

  • 64

    Accessibility

    Visual factors better than
    that of 29% of websites

  • 58

    Best Practices

    More advanced features
    available than in
    20% of websites

  • 79

    SEO

    Google-friendlier than
    40% of websites

w3cschool.cn

w3cschool官网 - 1000多本编程教程免费学

Page Load Speed

24.4 sec in total

First Response

531 ms

Resources Loaded

23.1 sec

Page Rendered

771 ms

w3cschool.cn screenshot

About Website

Click here to check amazing W 3 Cschool content for China. Otherwise, check out these important facts you probably never knew about w3cschool.cn

w3cschool启用中文品牌名--编程狮,是一个专业的W3C前端开发及编程入门学习平台,提供包括HTML,CSS,Javascript,jQuery,C,PHP,Java,Python,Sql,Mysql等编程语言和开源技术的在线教程及使用手册,是类国外w3schools的W3C学习社区及菜鸟编程平台。

Visit w3cschool.cn

Key Findings

We analyzed W3cschool.cn page load time and found that the first response time was 531 ms and then it took 23.9 sec to load all DOM resources and completely render a web page. This is a poor result, as 95% of websites can load faster.

Performance Metrics

w3cschool.cn performance score

52

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value2.6 s

62/100

10%

LCP (Largest Contentful Paint)

Value9.2 s

1/100

25%

SI (Speed Index)

Value9.1 s

13/100

10%

TBT (Total Blocking Time)

Value360 ms

72/100

30%

CLS (Cumulative Layout Shift)

Value0

100/100

15%

TTI (Time to Interactive)

Value4.6 s

81/100

10%

Network Requests Diagram

w3cschool.cn

531 ms

www.w3cschool.cn

1273 ms

common.css

232 ms

w10.css

465 ms

login.css

684 ms

Our browser made a total of 384 requests to load all elements on the main page. We found that 7% of them (25 requests) were addressed to the original W3cschool.cn, 89% (341 requests) were made to Atts.w3cschool.cn and 5% (18 requests) were made to 7n.w3cschool.cn. The less responsive or slowest element that took the longest time to load (4.7 sec) relates to the external source Atts.w3cschool.cn.

Page Optimization Overview & Recommendations

Page size can be reduced by 1.9 MB (18%)

Content Size

10.3 MB

After Optimization

8.4 MB

In fact, the total size of W3cschool.cn main page is 10.3 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. 80% of websites need less resources to load and that’s why Accessify’s recommendations for optimization and resource minification can be helpful for this project. Images take 9.9 MB which makes up the majority of the site volume.

HTML Optimization

-85%

Potential reduce by 189.2 kB

  • Original 221.8 kB
  • After minification 219.4 kB
  • After compression 32.6 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 189.2 kB or 85% of the original size.

Image Optimization

-17%

Potential reduce by 1.6 MB

  • Original 9.9 MB
  • After minification 8.3 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. Obviously, W 3 Cschool needs image optimization as it can save up to 1.6 MB or 17% of the original volume. The most popular and efficient tools for JPEG and PNG image optimization are Jpegoptim and PNG Crush.

JavaScript Optimization

-33%

Potential reduce by 37.2 kB

  • Original 112.8 kB
  • After minification 112.8 kB
  • After compression 75.6 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 37.2 kB or 33% of the original size.

CSS Optimization

-21%

Potential reduce by 4.3 kB

  • Original 20.2 kB
  • After minification 20.2 kB
  • After compression 15.9 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. W3cschool.cn needs all CSS files to be minified and compressed as it can save up to 4.3 kB or 21% of the original size.

Requests Breakdown

Number of requests can be reduced by 4 (1%)

Requests Now

381

After Optimization

377

The browser has sent 381 CSS, Javascripts, AJAX and image requests in order to completely render the main page of W 3 Cschool. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 5 to 1 for JavaScripts and as a result speed up the page load time.

Accessibility Review

w3cschool.cn accessibility score

64

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

Buttons do not have an accessible name

High

Form elements do not have associated labels

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

w3cschool.cn 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

SEO Factors

w3cschool.cn SEO score

79

Search Engine Optimization Advices

Language and Encoding

  • Language Detected

    ZH

  • Language Claimed

    ZH

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise W3cschool.cn can be misinterpreted by Google and other search engines. Our service has detected that Chinese is used on the page, and it matches the claimed language. Our system also found out that W3cschool.cn 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 W 3 Cschool. 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: