Report Summary

  • 12

    Performance

    Renders faster than
    25% of other websites

  • 90

    Accessibility

    Visual factors better than
    that of 76% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    57% of websites

  • 86

    SEO

    Google-friendlier than
    61% of websites

zis.ch

Zurich International School | ZIS - Zürich, Switzerland

Page Load Speed

2 sec in total

First Response

163 ms

Resources Loaded

1.6 sec

Page Rendered

229 ms

zis.ch screenshot

About Website

Visit zis.ch now to see the best up-to-date ZIS content for Switzerland and also check out these interesting facts you probably never knew about zis.ch

Zurich International School is a leading international school in Switzerland, offering an international education in English for children aged 3 to 18 years as well as a English/German Bilingual Pathw...

Visit zis.ch

Key Findings

We analyzed Zis.ch page load time and found that the first response time was 163 ms and then it took 1.9 sec to load all DOM resources and completely render a web page. This is quite a good result, as only 30% of websites can load faster.

Performance Metrics

zis.ch performance score

12

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value4.3 s

17/100

10%

LCP (Largest Contentful Paint)

Value19.8 s

0/100

25%

SI (Speed Index)

Value15.7 s

0/100

10%

TBT (Total Blocking Time)

Value4,060 ms

1/100

30%

CLS (Cumulative Layout Shift)

Value0.199

62/100

15%

TTI (Time to Interactive)

Value17.8 s

4/100

10%

Network Requests Diagram

zis.ch

163 ms

www.zis.ch

352 ms

styles.cfm

67 ms

ss.css

31 ms

jquery.min.js

27 ms

Our browser made a total of 150 requests to load all elements on the main page. We found that 44% of them (66 requests) were addressed to the original Zis.ch, 21% (32 requests) were made to Pbs.twimg.com and 12% (18 requests) were made to Newjs.finalsite.com. The less responsive or slowest element that took the longest time to load (514 ms) relates to the external source Pbs.twimg.com.

Page Optimization Overview & Recommendations

Page size can be reduced by 1.6 MB (22%)

Content Size

7.2 MB

After Optimization

5.6 MB

In fact, the total size of Zis.ch main page is 7.2 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 5.2 MB which makes up the majority of the site volume.

HTML Optimization

-79%

Potential reduce by 53.9 kB

  • Original 68.2 kB
  • After minification 62.5 kB
  • After compression 14.3 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 53.9 kB or 79% of the original size.

Image Optimization

-3%

Potential reduce by 143.0 kB

  • Original 5.2 MB
  • After minification 5.0 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. ZIS images are well optimized though.

JavaScript Optimization

-69%

Potential reduce by 1.2 MB

  • Original 1.7 MB
  • After minification 1.6 MB
  • After compression 529.0 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 1.2 MB or 69% of the original size.

CSS Optimization

-83%

Potential reduce by 184.6 kB

  • Original 221.2 kB
  • After minification 171.6 kB
  • After compression 36.5 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. Zis.ch needs all CSS files to be minified and compressed as it can save up to 184.6 kB or 83% of the original size.

Requests Breakdown

Number of requests can be reduced by 69 (47%)

Requests Now

148

After Optimization

79

The browser has sent 148 CSS, Javascripts, AJAX and image requests in order to completely render the main page of ZIS. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 36 to 1 for JavaScripts and from 28 to 1 for CSS and as a result speed up the page load time.

Accessibility Review

zis.ch accessibility score

90

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

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.

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

Lists do not contain only <li> elements and script supporting elements (<script> and <template>).

High

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

Best Practices

zis.ch best practices score

83

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

General

Impact

Issue

Low

Detected JavaScript libraries

High

Missing source maps for large first-party JavaScript

SEO Factors

zis.ch SEO score

86

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

Links do not have descriptive text

Crawling and Indexing

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

Impact

Issue

High

Links are not crawlable

Mobile Friendly

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/).

Impact

Issue

High

Document uses legible font sizes

Language and Encoding

  • Language Detected

    EN

  • Language Claimed

    N/A

  • Encoding

    ISO-8859-1

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Zis.ch can be misinterpreted by Google and other search engines. Our service has detected that English 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 Zis.ch main page’s claimed encoding is iso-8859-1. 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

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