Report Summary

  • 7

    Performance

    Renders faster than
    21% of other websites

  • 86

    Accessibility

    Visual factors better than
    that of 63% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    57% of websites

  • 90

    SEO

    Google-friendlier than
    69% of websites

eso.org

ESO

Page Load Speed

4.7 sec in total

First Response

394 ms

Resources Loaded

4 sec

Page Rendered

387 ms

eso.org screenshot

About Website

Click here to check amazing ESO content for China. Otherwise, check out these important facts you probably never knew about eso.org

ESO, European Organisation for Astronomical Research in the Southern Hemisphere

Visit eso.org

Key Findings

We analyzed Eso.org page load time and found that the first response time was 394 ms and then it took 4.4 sec to load all DOM resources and completely render a web page. This is a poor result, as 65% of websites can load faster.

Performance Metrics

eso.org performance score

7

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.8 s

28/100

10%

LCP (Largest Contentful Paint)

Value15.8 s

0/100

25%

SI (Speed Index)

Value7.6 s

26/100

10%

TBT (Total Blocking Time)

Value3,530 ms

1/100

30%

CLS (Cumulative Layout Shift)

Value0.734

6/100

15%

TTI (Time to Interactive)

Value20.7 s

2/100

10%

Network Requests Diagram

eso.org

394 ms

716 ms

main.7cf8f1a4c4d7.css

300 ms

analytics.js

5 ms

extras.8eef4882228f.css

101 ms

Our browser made a total of 51 requests to load all elements on the main page. We found that 43% of them (22 requests) were addressed to the original Eso.org, 31% (16 requests) were made to Cdn.eso.org and 8% (4 requests) were made to S.ytimg.com. The less responsive or slowest element that took the longest time to load (1.6 sec) belongs to the original domain Eso.org.

Page Optimization Overview & Recommendations

Page size can be reduced by 792.8 kB (16%)

Content Size

4.8 MB

After Optimization

4.1 MB

In fact, the total size of Eso.org main page is 4.8 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. 55% of websites need less resources to load. Images take 3.9 MB which makes up the majority of the site volume.

HTML Optimization

-86%

Potential reduce by 168.9 kB

  • Original 196.1 kB
  • After minification 177.0 kB
  • After compression 27.2 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 168.9 kB or 86% of the original size.

Image Optimization

-2%

Potential reduce by 78.2 kB

  • Original 3.9 MB
  • After minification 3.8 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. ESO images are well optimized though.

JavaScript Optimization

-60%

Potential reduce by 148.4 kB

  • Original 247.6 kB
  • After minification 247.3 kB
  • After compression 99.2 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 148.4 kB or 60% of the original size.

CSS Optimization

-83%

Potential reduce by 397.3 kB

  • Original 480.0 kB
  • After minification 480.0 kB
  • After compression 82.8 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. Eso.org needs all CSS files to be minified and compressed as it can save up to 397.3 kB or 83% of the original size.

Requests Breakdown

Number of requests can be reduced by 8 (20%)

Requests Now

40

After Optimization

32

The browser has sent 40 CSS, Javascripts, AJAX and image requests in order to completely render the main page of ESO. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 9 to 1 for JavaScripts and as a result speed up the page load time.

Accessibility Review

eso.org accessibility score

86

Accessibility Issues

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-hidden="true"] elements contain focusable descendents

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

High

Links do not have a discernible 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.

Best Practices

eso.org 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

eso.org SEO score

90

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

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

High

Tap targets are not sized appropriately

Language and Encoding

  • Language Detected

    EN

  • Language Claimed

    EN

  • Encoding

    UTF-8

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