Report Summary

  • 22

    Performance

    Renders faster than
    40% of other websites

  • 66

    Accessibility

    Visual factors better than
    that of 31% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    35% of websites

  • 85

    SEO

    Google-friendlier than
    55% of websites

jwst-docs.stsci.edu

JWST User Documentation Home - JWST User Documentation

Page Load Speed

2.6 sec in total

First Response

111 ms

Resources Loaded

1.7 sec

Page Rendered

750 ms

jwst-docs.stsci.edu screenshot

About Website

Click here to check amazing JWST Docs Stsci content for United States. Otherwise, check out these important facts you probably never knew about jwst-docs.stsci.edu

Welcome to the JWST User Documentation Homepage This website holds a comprehensive collection of documentation (known as JDox) on the JWST spacecraft and instru

Visit jwst-docs.stsci.edu

Key Findings

We analyzed Jwst-docs.stsci.edu page load time and found that the first response time was 111 ms and then it took 2.4 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

jwst-docs.stsci.edu performance score

22

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value7.9 s

0/100

10%

LCP (Largest Contentful Paint)

Value9.0 s

1/100

25%

SI (Speed Index)

Value7.9 s

22/100

10%

TBT (Total Blocking Time)

Value2,120 ms

7/100

30%

CLS (Cumulative Layout Shift)

Value0.004

100/100

15%

TTI (Time to Interactive)

Value10.2 s

25/100

10%

Network Requests Diagram

jwst-docs.stsci.edu

111 ms

jwst-docs.stsci.edu

557 ms

js

281 ms

batch.js

249 ms

batch.js

247 ms

Our browser made a total of 78 requests to load all elements on the main page. We found that 85% of them (66 requests) were addressed to the original Jwst-docs.stsci.edu, 8% (6 requests) were made to Fonts.gstatic.com and 3% (2 requests) were made to Google-analytics.com. The less responsive or slowest element that took the longest time to load (557 ms) belongs to the original domain Jwst-docs.stsci.edu.

Page Optimization Overview & Recommendations

Page size can be reduced by 471.1 kB (60%)

Content Size

783.3 kB

After Optimization

312.3 kB

In fact, the total size of Jwst-docs.stsci.edu main page is 783.3 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. 70% of websites need less resources to load. HTML takes 354.0 kB which makes up the majority of the site volume.

HTML Optimization

-93%

Potential reduce by 330.2 kB

  • Original 354.0 kB
  • After minification 211.4 kB
  • After compression 23.8 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. This page needs HTML code to be minified as it can gain 142.6 kB, which is 40% of the original size. It is highly recommended that content of this web page should be compressed using GZIP, as it can save up to 330.2 kB or 93% of the original size.

Image Optimization

-67%

Potential reduce by 113.6 kB

  • Original 170.1 kB
  • After minification 56.5 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. Obviously, JWST Docs Stsci needs image optimization as it can save up to 113.6 kB or 67% of the original volume. The most popular and efficient tools for JPEG and PNG image optimization are Jpegoptim and PNG Crush.

JavaScript Optimization

-7%

Potential reduce by 7.2 kB

  • Original 106.3 kB
  • After minification 106.3 kB
  • After compression 99.1 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. This website has mostly compressed JavaScripts.

CSS Optimization

-13%

Potential reduce by 20.1 kB

  • Original 153.0 kB
  • After minification 152.9 kB
  • After compression 132.9 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. Jwst-docs.stsci.edu needs all CSS files to be minified and compressed as it can save up to 20.1 kB or 13% of the original size.

Requests Breakdown

Number of requests can be reduced by 61 (87%)

Requests Now

70

After Optimization

9

The browser has sent 70 CSS, Javascripts, AJAX and image requests in order to completely render the main page of JWST Docs Stsci. 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 20 to 1 for CSS and as a result speed up the page load time.

Accessibility Review

jwst-docs.stsci.edu accessibility score

66

Accessibility Issues

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.

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

Links do not have a discernible name

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

jwst-docs.stsci.edu best practices score

75

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

Browser errors were logged to the console

High

Missing source maps for large first-party JavaScript

SEO Factors

jwst-docs.stsci.edu SEO score

85

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

    EN

  • Language Claimed

    N/A

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Jwst-docs.stsci.edu 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 Jwst-docs.stsci.edu 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 JWST Docs Stsci. 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: