Access zim.vn. Anh Ngữ ZIM - Học Tiếng Anh cá nhân hoá & luyện thi chứng chỉ

name

value

score

weighting

FCP (First Contentful Paint)

Value4.9 s

10/100

10%

LCP (Largest Contentful Paint)

Value7.2 s

5/100

25%

SI (Speed Index)

Value19.5 s

0/100

10%

TBT (Total Blocking Time)

Value7,250 ms

0/100

30%

CLS (Cumulative Layout Shift)

Value0.005

100/100

15%

TTI (Time to Interactive)

Value27.9 s

0/100

10%

zim.vn

525 ms

zim.vn

1909 ms

tex-mml-chtml.js

43 ms

gtm.js

80 ms

af5bc2a68f845782.css

1360 ms

Our browser made a total of 49 requests to load all elements on the main page. We found that 82% of them (40 requests) were addressed to the original Zim.vn, 14% (7 requests) were made to Fonts.gstatic.com and 2% (1 request) were made to Cdn.jsdelivr.net. The less responsive or slowest element that took the longest time to load (2.9 sec) belongs to the original domain Zim.vn.

Content Size

1.8 MB

After Optimization

964.3 kB

In fact, the total size of Zim.vn main page is 1.8 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. 50% of websites need less resources to load. HTML takes 946.8 kB which makes up the majority of the site volume.

HTML Optimization

-84%

Potential reduce by 800.0 kB

Original 946.8 kB
After minification 945.8 kB
After compression 146.8 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 800.0 kB or 84% of the original size.

Image Optimization

-1%

Potential reduce by 8.2 kB

Original 825.7 kB
After minification 817.5 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. ZIM images are well optimized though.

Requests Now

After Optimization

The browser has sent 40 CSS, Javascripts, AJAX and image requests in order to completely render the main page of ZIM. 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 4 to 1 for CSS and as a result speed up the page load time.

Accessibility Issues

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.

High

Buttons do not have an accessible name

High

Image elements do not have [alt] attributes

High

Links do not have a discernible name

These are opportunities to improve the legibility of your content.

High

Background and foreground colors do not have a sufficient contrast ratio.

These are opportunities to improve keyboard navigation in your application.

High

Heading elements are not in a sequentially-descending order

Areas of Improvement

High

Does not use HTTPS

Low

Ensure CSP is effective against XSS attacks

Low

Detected JavaScript libraries

High

Missing source maps for large first-party JavaScript

Search Engine Optimization Advices

Format your HTML in a way that enables crawlers to better understand your app’s content.

High

Image elements do not have [alt] attributes

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/).

High

Document uses legible font sizes

Language and Encoding

Language Detected

VI
Language Claimed

VI
Encoding

UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Zim.vn can be misinterpreted by Google and other search engines. Our service has detected that Vietnamese is used on the page, and it matches the claimed language. Our system also found out that Zim.vn 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 data is detected on the main page of ZIM. This is the best way to make the web page social media friendly. Here is how it looks like on Facebook: