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w3school.com.cn screenshot

Report Summary

  • 56

    Performance

    Renders faster than
    73% of other websites

  • 100

    Accessibility

    Visual factors better than
    that of 97% of websites

  • 92

    Best Practices

    More advanced features
    available than in
    81% of websites

  • 67

    SEO

    Google-friendlier than
    25% of websites

w3school.com.cn

w3school 在线教程

Page Load Speed

20.3 sec in total

First Response

5.4 sec

Resources Loaded

6.6 sec

Page Rendered

8.2 sec

w3school.com.cn screenshot

About Website

Visit w3school.com.cn now to see the best up-to-date W 3 School content for China and also check out these interesting facts you probably never knew about w3school.com.cn

全球最大的中文 Web 技术教程。

Visit w3school.com.cn

Key Findings

We analyzed W3school.com.cn page load time and found that the first response time was 5.4 sec and then it took 14.9 sec to load all DOM resources and completely render a web page. This is a poor result, as 90% of websites can load faster.

Performance Metrics

w3school.com.cn performance score

56

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value6.1 s

3/100

10%

LCP (Largest Contentful Paint)

Value6.1 s

12/100

25%

SI (Speed Index)

Value7.4 s

27/100

10%

TBT (Total Blocking Time)

Value140 ms

95/100

30%

CLS (Cumulative Layout Shift)

Value0

100/100

15%

TTI (Time to Interactive)

Value6.4 s

60/100

10%

Network Requests Diagram

w3school.com.cn

5442 ms

c5.css

1774 ms

wrapper.png

1617 ms

bg.png

2796 ms

icon2.png

1802 ms

Our browser made a total of 13 requests to load all elements on the main page. We found that all of those requests were addressed to W3school.com.cn and no external sources were called. The less responsive or slowest element that took the longest time to load (5.4 sec) belongs to the original domain W3school.com.cn.

Page Optimization Overview & Recommendations

Page size can be reduced by 57.6 kB (37%)

Content Size

155.9 kB

After Optimization

98.2 kB

  • HTML
  • Images
  • CSS

In fact, the total size of W3school.com.cn main page is 155.9 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. Only 10% of websites need less resources to load. Images take 107.5 kB which makes up the majority of the site volume.

HTML Optimization

-70%

Potential reduce by 9.8 kB

  • Original 13.9 kB
  • After minification 13.9 kB
  • After compression 4.1 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 9.8 kB or 70% of the original size.

Image Optimization

-18%

Potential reduce by 19.6 kB

  • Original 107.5 kB
  • After minification 87.8 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. Obviously, W 3 School needs image optimization as it can save up to 19.6 kB or 18% of the original volume. The most popular and efficient tools for JPEG and PNG image optimization are Jpegoptim and PNG Crush.

CSS Optimization

-82%

Potential reduce by 28.2 kB

  • Original 34.5 kB
  • After minification 28.8 kB
  • After compression 6.3 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. W3school.com.cn needs all CSS files to be minified and compressed as it can save up to 28.2 kB or 82% of the original size.

Requests Breakdown

We found no issues to fix!

Requests Now

12

After Optimization

12

  • Images
  • CSS

The browser has sent 12 CSS, Javascripts, AJAX and image requests in order to completely render the main page of W 3 School. According to our analytics all requests are already optimized.

Network Requests Diagram

w3school.com.cn

w3school.com.cn

5442 ms

c5.css

c5.css

1774 ms

wrapper.png

wrapper.png

1617 ms

bg.png

bg.png

2796 ms

icon2.png

icon2.png

1802 ms

icon3.png

icon3.png

1803 ms

icon4.png

icon4.png

1804 ms

icon5.png

icon5.png

1973 ms

icon6.png

icon6.png

1803 ms

icon7.png

icon7.png

2423 ms

icon8.png

icon8.png

1872 ms

footer.png

footer.png

513 ms

alert.png

alert.png

330 ms

Accessibility Review

w3school.com.cn accessibility score

100

Accessibility Issues

Best Practices

w3school.com.cn 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

SEO Factors

w3school.com.cn SEO score

67

Search Engine Optimization Advices

Crawling and Indexing

To appear in search results, crawlers need access to your app.

Impact

Issue

High

robots.txt is not valid

Language and Encoding

  • Language Detected

    ZH

  • Language Claimed

    ZH

  • Encoding

    GB2312

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise W3school.com.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 W3school.com.cn main page’s claimed encoding is gb2312. Changing it to UTF-8 can be a good choice, as this format is commonly used for encoding all over the web and thus their visitors won’t have any troubles with symbol transcription or reading.

Social Sharing Optimization

w3school.com.cn

Open Graph description is not detected on the main page of W 3 School. 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: