Tools & Wizards About Us
51hei.com screenshot

Report Summary

  • 93

    Performance

    Renders faster than
    92% of other websites

  • 53

    Accessibility

    Visual factors better than
    that of 22% of websites

  • 58

    Best Practices

    More advanced features
    available than in
    19% of websites

  • 69

    SEO

    Google-friendlier than
    28% of websites

51hei.com

单片机教程网-51 stm32 arm MCU 电子技术学习与研究

Page Load Speed

27.5 sec in total

First Response

3.2 sec

Resources Loaded

24 sec

Page Rendered

274 ms

51hei.com screenshot

About Website

Click here to check amazing 51 Hei content for China. Otherwise, check out these important facts you probably never knew about 51hei.com

本站提供单片机视频教程,51单片机学习开发资料,C语言汇编教程,仿真软件下载,是学习者和电子工程师不容错过的技术站点

Visit 51hei.com

Key Findings

We analyzed 51hei.com page load time and found that the first response time was 3.2 sec and then it took 24.2 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

51hei.com performance score

93

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value1.5 s

95/100

10%

LCP (Largest Contentful Paint)

Value2.3 s

93/100

25%

SI (Speed Index)

Value4.9 s

66/100

10%

TBT (Total Blocking Time)

Value30 ms

100/100

30%

CLS (Cumulative Layout Shift)

Value0.002

100/100

15%

TTI (Time to Interactive)

Value3.8 s

90/100

10%

Network Requests Diagram

www.51hei.com

3232 ms

main.css

4499 ms

foucs.css

781 ms

jquery-1.4.2.min.js

9056 ms

yu.js

5399 ms

Our browser made a total of 63 requests to load all elements on the main page. We found that 86% of them (54 requests) were addressed to the original 51hei.com, 10% (6 requests) were made to Bdimg.share.baidu.com and 3% (2 requests) were made to Hm.baidu.com. The less responsive or slowest element that took the longest time to load (12.1 sec) belongs to the original domain 51hei.com.

Page Optimization Overview & Recommendations

Page size can be reduced by 228.5 kB (56%)

Content Size

409.6 kB

After Optimization

181.0 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of 51hei.com main page is 409.6 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. 20% of websites need less resources to load. Javascripts take 224.0 kB which makes up the majority of the site volume.

HTML Optimization

-78%

Potential reduce by 41.4 kB

  • Original 53.4 kB
  • After minification 51.8 kB
  • After compression 11.9 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 41.4 kB or 78% of the original size.

Image Optimization

-6%

Potential reduce by 5.3 kB

  • Original 96.6 kB
  • After minification 91.2 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. 51 Hei images are well optimized though.

JavaScript Optimization

-69%

Potential reduce by 153.6 kB

  • Original 224.0 kB
  • After minification 223.1 kB
  • After compression 70.4 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 153.6 kB or 69% of the original size.

CSS Optimization

-79%

Potential reduce by 28.2 kB

  • Original 35.6 kB
  • After minification 30.4 kB
  • After compression 7.5 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. 51hei.com needs all CSS files to be minified and compressed as it can save up to 28.2 kB or 79% of the original size.

Requests Breakdown

Number of requests can be reduced by 27 (44%)

Requests Now

62

After Optimization

35

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 62 CSS, Javascripts, AJAX and image requests in order to completely render the main page of 51 Hei. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 11 to 1 for JavaScripts and as a result speed up the page load time.

Network Requests Diagram

www.51hei.com

www.51hei.com

3232 ms

main.css

main.css

4499 ms

foucs.css

foucs.css

781 ms

jquery-1.4.2.min.js

jquery-1.4.2.min.js

9056 ms

yu.js

yu.js

5399 ms

tb.js

tb.js

2941 ms

api.php

api.php

2216 ms

login.js

login.js

2595 ms

tj.js

tj.js

2666 ms

wpa.js

wpa.js

4788 ms

bg_body.png

bg_body.png

396 ms

51.gif

51.gif

1136 ms

diy.gif

diy.gif

789 ms

24h.jpg

24h.jpg

5839 ms

xue.gif

xue.gif

2369 ms

stm.gif

stm.gif

1503 ms

m3.gif

m3.gif

1799 ms

fangzhen.gif

fangzhen.gif

1881 ms

dzdiy.png

dzdiy.png

3183 ms

moni.gif

moni.gif

2243 ms

fuwu.jpg

fuwu.jpg

9037 ms

x03.gif

x03.gif

10845 ms

qq2.png

qq2.png

5368 ms

suo1.gif

suo1.gif

8908 ms

suo2.gif

suo2.gif

6079 ms

suo3.gif

suo3.gif

7576 ms

suo4.gif

suo4.gif

9006 ms

suo5.gif

suo5.gif

12070 ms

logo_bottom.gif

logo_bottom.gif

9816 ms

topbar_l.png

topbar_l.png

5151 ms

topbar_dot.png

topbar_dot.png

5510 ms

51heilogo.gif

51heilogo.gif

5883 ms

headerSearch_input.png

headerSearch_input.png

6193 ms

headerSearch_btn.png

headerSearch_btn.png

10308 ms

menu_l1.gif

menu_l1.gif

6571 ms

menu_l2.gif

menu_l2.gif

6245 ms

menu2_icon.gif

menu2_icon.gif

8129 ms

newLbox_title.png

newLbox_title.png

6633 ms

newLbox_h2.png

newLbox_h2.png

7284 ms

shidian_th.png

shidian_th.png

6930 ms

bg_r.png

bg_r.png

6961 ms

fxtt.png

fxtt.png

7323 ms

dot_list1.gif

dot_list1.gif

7323 ms

hotQianzheng_th.png

hotQianzheng_th.png

7649 ms

isbox_h2.gif

isbox_h2.gif

8109 ms

bg_qzw.gif

bg_qzw.gif

7684 ms

cion_ht.gif

cion_ht.gif

9444 ms

newstab_tab.png

newstab_tab.png

8025 ms

tabl1.gif

tabl1.gif

9057 ms

tabl2.gif

tabl2.gif

11575 ms

dot_list3.gif

dot_list3.gif

11779 ms

flink_tab.gif

flink_tab.gif

11851 ms

ft1.gif

ft1.gif

9393 ms

fc.gif

fc.gif

11289 ms

h.js

h.js

5792 ms

hm.gif

hm.gif

347 ms

shell_v2.js

shell_v2.js

588 ms

logger.js

logger.js

300 ms

bds_s_v2.js

bds_s_v2.js

904 ms

bdsstyle.css

bdsstyle.css

295 ms

getnum

getnum

1566 ms

is.png

is.png

295 ms

sc.png

sc.png

315 ms

Accessibility Review

51hei.com accessibility score

53

Accessibility Issues

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

Image elements do not have [alt] attributes

High

Form elements do not have associated labels

High

Links do not have a discernible name

Tables and lists

These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.

Impact

Issue

High

List items (<li>) are not contained within <ul> or <ol> parent elements.

Best Practices

51hei.com 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

SEO Factors

51hei.com SEO score

69

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

Image elements do not have [alt] attributes

Language and Encoding

  • Language Detected

    ZH

  • Language Claimed

    N/A

  • Encoding

    GB2312

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise 51hei.com can be misinterpreted by Google and other search engines. Our service has detected that Chinese 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 51hei.com 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

51hei.com

Open Graph description is not detected on the main page of 51 Hei. 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: