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coursera.org Desktop Performance
56/100
These metrics represent real-world Chrome users experience viewing coursera.org web page. Reports are focused on loading performance and other critical factors that most affect user experience. Follow our guide to track, optimize, and improve the quality of your web pages.
User Loading Experience
Largest Contentful Paint
Cumulative Layout Shift
First Contentful Paint
First Input Delay
Metrics
Largest Contentful Paint42/100 2.7 s
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn More
Time to Interactive47/100 4.7 s
Time to interactive is the amount of time it takes for the page to become fully interactive. Learn more.
Total Blocking Time53/100 330 ms
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more.
Speed Index56/100 2.1 s
Speed Index shows how quickly the contents of a page are visibly populated. Learn more.
First Contentful Paint79/100 1.1 s
First Contentful Paint marks the time at which the first text or image is painted. Learn more.
Cumulative Layout Shift100/100 0.008
Cumulative Layout Shift measures the movement of visible elements within the viewport. Learn more.
Should Fix (16)
Opportunities
These suggestions can help your page load faster. They don't directly affect the Performance score.
Remove unused JavaScript
Potential savings of 504 KiB
1,730 ms
Avoid multiple page redirects
Potential savings of 340 ms
340 ms
Enable text compression
Potential savings of 226 KiB
200 ms
Eliminate render-blocking resources
Potential savings of 170 ms
170 ms
Properly size images
Potential savings of 61 KiB
80 ms
Diagnostics
More information about the performance of your application. These numbers don't directly affect the Performance score.
Ensure text remains visible during webfont load
Serve static assets with an efficient cache policy
49 resources found
Minimize main-thread work
2.4 s
Reduce JavaScript execution time
1.5 s
Avoid an excessive DOM size
848 elements
Avoid chaining critical requests
4 chains found
User Timing marks and measures
23 user timings
Avoid long main-thread tasks
5 long tasks found
Avoid large layout shifts
5 elements found
Keep request counts low and transfer sizes small
213 requests • 2,127 KiB
Largest Contentful Paint element
1 element found
Passed Audits (14)
Minify JavaScript
Potential savings of 5 KiB
Serve images in next-gen formats
Efficiently encode images
Preload key requests
Uses passive listeners to improve scrolling performance
Initial server response time was short
Root document took 390 ms
Preconnect to required origins
Avoids enormous network payloads
Total size was 2,127 KiB
Minify CSS
Defer offscreen images
Potential savings of 69 KiB
Remove unused CSS
Potential savings of 44 KiB
Avoids `document.write()`
Minimize third-party usage
Third-party code blocked the main thread for 0 ms
Use video formats for animated content

coursera.org Desktop SEO
100/100
These checks ensure that your page is optimized for search engine results ranking. There are additional factors Lighthouse does not check that may affect your search ranking. Learn more. Run these additional validators on your site to check additional SEO best practices.
Passed Audits (12)
Image elements have `[alt]` attributes
Document has a `<title>` element
Document has a meta description
Document avoids plugins
Document has a valid `rel=canonical`
robots.txt is valid
Has a `<meta name="viewport">` tag with `width` or `initial-scale`
Links have descriptive text
Document has a valid `hreflang`
Links are crawlable
Page isn’t blocked from indexing
Page has successful HTTP status code

coursera.org Desktop Best Practices
77/100
These checks highlight opportunities to improve the overall code health of coursera.org page. Current recommendations will help to make your page fast and secure, to create a good user experience and to avoid deprecated technologies.
Should Fix (3)
User Experience
Displays images with incorrect aspect ratio
General
Browser errors were logged to the console
Trust and Safety
Does not use HTTPS
1 insecure request found
Passed Audits (11)
Properly defines charset
Serves images with appropriate resolution
Detected JavaScript libraries
Avoids deprecated APIs
Avoids front-end JavaScript libraries with known security vulnerabilities
Page has the HTML doctype
Avoids Application Cache
Allows users to paste into password fields
Links to cross-origin destinations are safe
Avoids requesting the geolocation permission on page load
Avoids requesting the notification permission on page load

coursera.org Desktop Progressive Web App
22/100
These checks validate the aspects of a Progressive Web App. Learn more. These checks are required by the baseline PWA Checklist but are not automatically checked by Lighthouse. They do not affect your score but it's important that you verify them manually.
Should Fix (9)
Fast and reliable
Current page does not respond with a 200 when offline
Page load is not fast enough on mobile networks
Interactive on simulated mobile network at 20.7 s
`start_url` does not respond with a 200 when offline
Installable
Does not register a service worker that controls page and `start_url`
Web app manifest does not meet the installability requirements
Does not use HTTPS
1 insecure request found
PWA Optimized
Is not configured for a custom splash screen
Does not set a theme color for the address bar.
Manifest doesn't have a maskable icon
Passed Audits (4)
Provides a valid `apple-touch-icon`
Contains some content when JavaScript is not available
Has a `<meta name="viewport">` tag with `width` or `initial-scale`
Redirects HTTP traffic to HTTPS

coursera.org Desktop Accessibility
90/100
These checks highlight opportunities to improve the accessibility of your web app. Only a subset of accessibility issues can be automatically detected so manual testing is also encouraged. These items address areas which an automated testing tool cannot cover. Learn more in our guide on conducting an accessibility review.
Should Fix (3)
Tables and lists
These are opportunities to to improve the experience of reading tabular or list data using assistive technology, like a screen reader.
List items (`<li>`) are not contained within `<ul>` or `<ol>` parent elements.
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.
Elements with an ARIA `[role]` that require children to contain a specific `[role]` are missing some or all of those required children.
ARIA input fields do not have accessible names
Passed Audits (23)
Links have a discernible name
Image elements have `[alt]` attributes
`[id]` attributes on active, focusable elements are unique
`[aria-*]` attributes have valid values
`[role]` values are valid
`[aria-*]` attributes match their roles
`[aria-hidden="true"]` elements do not contain focusable descendents
`[aria-*]` attributes are valid and not misspelled
Document has a `<title>` element
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
`[aria-hidden="true"]` is not present on the document `<body>`
ARIA IDs are unique
No element has a `[tabindex]` value greater than 0
`<html>` element has a valid value for its `[lang]` attribute
The page contains a heading, skip link, or landmark region
Heading elements appear in a sequentially-descending order
`[role]`s are contained by their required parent element
`<html>` element has a `[lang]` attribute
`[role]`s have all required `[aria-*]` attributes
Buttons have an accessible name
Background and foreground colors have a sufficient contrast ratio
Form elements have associated labels

Desktop Speed
74/100
These checks analyze the performance of coursera.org on desktop devices and return PageSpeed score and information on how to improve the load time. What makes a good Progressive Web App?
Should Fix (5)
Eliminate render-blocking JavaScript and CSS in above-the-fold content
Avoid landing page redirects
Reduce server response time
Leverage browser caching
Optimize images
Passed Audits (5)
Enable compression
Minify CSS
Minify HTML
Minify JavaScript
Prioritize visible content
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