Report Summary

  • 5

    Performance

    Renders faster than
    21% of other websites

  • 67

    Accessibility

    Visual factors better than
    that of 32% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    56% of websites

  • 86

    SEO

    Google-friendlier than
    60% of websites

Page Load Speed

3 sec in total

First Response

268 ms

Resources Loaded

2.5 sec

Page Rendered

169 ms

stem.org.uk screenshot

About Website

Visit stem.org.uk now to see the best up-to-date Stem content for United Kingdom and also check out these interesting facts you probably never knew about stem.org.uk

Visit stem.org.uk

Key Findings

We analyzed Stem.org.uk page load time and found that the first response time was 268 ms and then it took 2.7 sec to load all DOM resources and completely render a web page. This is a poor result, as 50% of websites can load faster.

Performance Metrics

stem.org.uk performance score

5

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value5.5 s

6/100

10%

LCP (Largest Contentful Paint)

Value13.7 s

0/100

25%

SI (Speed Index)

Value8.9 s

15/100

10%

TBT (Total Blocking Time)

Value2,680 ms

4/100

30%

CLS (Cumulative Layout Shift)

Value0.966

2/100

15%

TTI (Time to Interactive)

Value12.1 s

16/100

10%

Network Requests Diagram

stem.org.uk

268 ms

www.stem.org.uk

473 ms

css_kShW4RPmRstZ3SpIC-ZvVGNFVAi0WEMuCnI0ZkYIaFw.css

110 ms

css_pJ4e_CLkI9bIX5F4ok4auzNtUfM5qcTiqtlX1yVw4H0.css

219 ms

css_atkFGFlvG6sSQcIj6Q73rpgsXhtr58AwITc2aQjVotk.css

263 ms

Our browser made a total of 34 requests to load all elements on the main page. We found that 94% of them (32 requests) were addressed to the original Stem.org.uk, 6% (2 requests) were made to Google-analytics.com. The less responsive or slowest element that took the longest time to load (875 ms) belongs to the original domain Stem.org.uk.

Page Optimization Overview & Recommendations

Page size can be reduced by 448.9 kB (64%)

Content Size

697.0 kB

After Optimization

248.2 kB

In fact, the total size of Stem.org.uk main page is 697.0 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. 30% of websites need less resources to load. Javascripts take 324.9 kB which makes up the majority of the site volume.

HTML Optimization

-73%

Potential reduce by 20.5 kB

  • Original 27.9 kB
  • After minification 25.4 kB
  • After compression 7.4 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 20.5 kB or 73% of the original size.

Image Optimization

-11%

Potential reduce by 11.3 kB

  • Original 100.5 kB
  • After minification 89.2 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. Obviously, Stem needs image optimization as it can save up to 11.3 kB or 11% of the original volume. The most popular and efficient tools for JPEG and PNG image optimization are Jpegoptim and PNG Crush.

JavaScript Optimization

-69%

Potential reduce by 223.7 kB

  • Original 324.9 kB
  • After minification 274.5 kB
  • After compression 101.2 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 223.7 kB or 69% of the original size.

CSS Optimization

-79%

Potential reduce by 193.4 kB

  • Original 243.8 kB
  • After minification 242.6 kB
  • After compression 50.4 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. Stem.org.uk needs all CSS files to be minified and compressed as it can save up to 193.4 kB or 79% of the original size.

Requests Breakdown

Number of requests can be reduced by 11 (38%)

Requests Now

29

After Optimization

18

The browser has sent 29 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Stem. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 8 to 1 for JavaScripts and from 5 to 1 for CSS and as a result speed up the page load time.

Accessibility Review

stem.org.uk accessibility score

67

Accessibility Issues

Navigation

These are opportunities to improve keyboard navigation in your application.

Impact

Issue

High

[id] attributes on active, focusable elements are not unique

High

Heading elements are not in a sequentially-descending order

ARIA

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Impact

Issue

High

ARIA IDs are not unique

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

Best practices

These items highlight common accessibility best practices.

Impact

Issue

High

[user-scalable="no"] is used in the <meta name="viewport"> element or the [maximum-scale] attribute is less than 5.

Best Practices

stem.org.uk 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

SEO Factors

stem.org.uk SEO score

86

Search Engine Optimization Advices

Crawling and Indexing

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

Impact

Issue

High

Links are not crawlable

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

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

    N/A

  • Language Claimed

    N/A

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Stem.org.uk can be misinterpreted by Google and other search engines. Unfortunately we cannot identify language used on the page (probably there is a mix of languages, too little text or something else) and no language is claimed in <html> or <meta> tags either. Our system also found out that Stem.org.uk 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 Stem. 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: