Tools & Wizards About Us
archive.ck12.org screenshot

Report Summary

  • 16

    Performance

    Renders faster than
    30% of other websites

  • 89

    Accessibility

    Visual factors better than
    that of 72% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    36% of websites

  • 76

    SEO

    Google-friendlier than
    35% of websites

archive.ck12.org

CK12-Foundation

Page Load Speed

1.6 sec in total

First Response

354 ms

Resources Loaded

1 sec

Page Rendered

230 ms

archive.ck12.org screenshot

About Website

Visit archive.ck12.org now to see the best up-to-date Archive CK12 content for United States and also check out these interesting facts you probably never knew about archive.ck12.org

CK-12 Foundation provides a library of free online textbooks, videos, exercises, flashcards, and real world applications for over 5000 concepts from arithmetic to history

Visit archive.ck12.org

Key Findings

We analyzed Archive.ck12.org page load time and found that the first response time was 354 ms and then it took 1.3 sec to load all DOM resources and completely render a web page. This is quite a good result, as only 25% of websites can load faster.

Performance Metrics

archive.ck12.org performance score

16

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value5.6 s

5/100

10%

LCP (Largest Contentful Paint)

Value5.8 s

15/100

25%

SI (Speed Index)

Value11.4 s

5/100

10%

TBT (Total Blocking Time)

Value4,990 ms

0/100

30%

CLS (Cumulative Layout Shift)

Value0.159

73/100

15%

TTI (Time to Interactive)

Value17.9 s

4/100

10%

Network Requests Diagram

www.ck12.org

354 ms

28889104.js

116 ms

master.css

15 ms

landing.css

19 ms

jquery.appdownload.css

19 ms

Our browser made a total of 82 requests to load all elements on the main page. We found that 0% of them (0 request) were addressed to the original Archive.ck12.org, 16% (13 requests) were made to Dvninqhj78q4x.cloudfront.net and 15% (12 requests) were made to D1mgzmvrdgdhkc.cloudfront.net. The less responsive or slowest element that took the longest time to load (354 ms) relates to the external source Ck12.org.

Page Optimization Overview & Recommendations

Page size can be reduced by 1.0 MB (55%)

Content Size

1.8 MB

After Optimization

832.7 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Archive.ck12.org main page is 1.8 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. 65% of websites need less resources to load. Javascripts take 1.1 MB which makes up the majority of the site volume.

HTML Optimization

-82%

Potential reduce by 64.5 kB

  • Original 79.2 kB
  • After minification 66.7 kB
  • After compression 14.6 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 12.5 kB, which is 16% 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 64.5 kB or 82% of the original size.

Image Optimization

-6%

Potential reduce by 22.5 kB

  • Original 405.2 kB
  • After minification 382.7 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. Archive CK12 images are well optimized though.

JavaScript Optimization

-64%

Potential reduce by 681.4 kB

  • Original 1.1 MB
  • After minification 1.1 MB
  • After compression 383.7 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 681.4 kB or 64% of the original size.

CSS Optimization

-83%

Potential reduce by 246.4 kB

  • Original 298.2 kB
  • After minification 287.7 kB
  • After compression 51.7 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. Archive.ck12.org needs all CSS files to be minified and compressed as it can save up to 246.4 kB or 83% of the original size.

Requests Breakdown

Number of requests can be reduced by 39 (51%)

Requests Now

76

After Optimization

37

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 76 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Archive CK12. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 27 to 1 for JavaScripts and from 4 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

www.ck12.org

www.ck12.org

354 ms

28889104.js

28889104.js

116 ms

master.css

master.css

15 ms

landing.css

landing.css

19 ms

jquery.appdownload.css

jquery.appdownload.css

19 ms

globals.js

globals.js

16 ms

dexterjs.min.js

dexterjs.min.js

7 ms

require.js

require.js

11 ms

element.js

element.js

48 ms

event

event

79 ms

atrk.js

atrk.js

91 ms

gtm.js

gtm.js

62 ms

1x1.gif

1x1.gif

63 ms

snow.png

snow.png

59 ms

logo_ck12.svg

logo_ck12.svg

31 ms

loading.gif

loading.gif

43 ms

snow_bck.svg

snow_bck.svg

46 ms

snowman.svg

snowman.svg

43 ms

small_bck2.png

small_bck2.png

46 ms

start_browse_sim.png

start_browse_sim.png

51 ms

sims2.png

sims2.png

54 ms

start_browse_plix.png

start_browse_plix.png

53 ms

plix2.png

plix2.png

58 ms

practice1.png

practice1.png

54 ms

practice2.png

practice2.png

53 ms

schools1.png

schools1.png

57 ms

schools2.png

schools2.png

61 ms

Apple.svg

Apple.svg

60 ms

Android_Robot.svg

Android_Robot.svg

61 ms

windows_1color.svg

windows_1color.svg

59 ms

chrome.svg

chrome.svg

138 ms

lydia_1024.png

lydia_1024.png

139 ms

helena_1024.png

helena_1024.png

139 ms

colin_1024.png

colin_1024.png

140 ms

apple-app-store.svg

apple-app-store.svg

135 ms

google-play-badge.png

google-play-badge.png

138 ms

icon_licence.png

icon_licence.png

140 ms

icon_loading.gif

icon_loading.gif

141 ms

snow3.png

snow3.png

34 ms

snow2.png

snow2.png

35 ms

subject-sprite-icons-sm.png

subject-sprite-icons-sm.png

48 ms

app_bck.gif

app_bck.gif

35 ms

translateelement.css

translateelement.css

223 ms

main.js

main.js

242 ms

main.js

main.js

50 ms

regular.woff

regular.woff

50 ms

bold.woff

bold.woff

51 ms

ck12.ttf

ck12.ttf

46 ms

McLaren-Regular.ttf

McLaren-Regular.ttf

51 ms

analytics.js

analytics.js

36 ms

zenbox.js

zenbox.js

184 ms

r.js

r.js

211 ms

event

event

264 ms

atrk.gif

atrk.gif

195 ms

linkid.js

linkid.js

81 ms

test.png

test.png

146 ms

platform.js

platform.js

166 ms

my

my

72 ms

flxweb.landing.new.js

flxweb.landing.new.js

37 ms

collect

collect

25 ms

close_big.png

close_big.png

32 ms

help-img.png

help-img.png

27 ms

loading.html

loading.html

65 ms

g.js

g.js

134 ms

maintenance.notification.js

maintenance.notification.js

11 ms

slick.min.js

slick.min.js

11 ms

jquery.hammer.min.js

jquery.hammer.min.js

13 ms

jquery.appdownload.js

jquery.appdownload.js

11 ms

element_main.js

element_main.js

41 ms

jquery-migrate-1.2.1.js

jquery-migrate-1.2.1.js

12 ms

maintenance.notification.view.js

maintenance.notification.view.js

11 ms

jquery.autocomplete-min.js

jquery.autocomplete-min.js

21 ms

load_large.gif

load_large.gif

55 ms

translate_24dp.png

translate_24dp.png

45 ms

l

l

46 ms

cleardot.gif

cleardot.gif

72 ms

ga-audiences

ga-audiences

47 ms

t.gif

t.gif

8 ms

te_ctrl3.gif

te_ctrl3.gif

19 ms

2

2

16 ms

iframe_api

iframe_api

23 ms

system.maintenance.notification.html.js

system.maintenance.notification.html.js

5 ms

Accessibility Review

archive.ck12.org accessibility score

89

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.

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

archive.ck12.org 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

User Experience

Impact

Issue

High

Serves images with low resolution

General

Impact

Issue

Low

Detected JavaScript libraries

High

Page has valid source maps

SEO Factors

archive.ck12.org SEO score

76

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

High

Image elements do not have [alt] attributes

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

High

Tap targets are not sized appropriately

Language and Encoding

  • Language Detected

    N/A

  • Language Claimed

    EN

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Archive.ck12.org 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), while the claimed language is English. Our system also found out that Archive.ck12.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

archive.ck12.org

Open Graph description is not detected on the main page of Archive CK12. 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: