AlexaWhoisServer InformationDesktop SpeedMobile SpeedMobile UsabilityHTML ErrorsPingTraceroute

CK12.ORG Welcome to CK-12 Foundation | CK-12 Foundation

ck12.org Website Information

Daily Unique Visits: 78,506

Daily Page Views: 471,036

Income Per Day: $942

Estimated Value: $678,240

ck12.org is registered under .ORG top-level domain. Please check other sites in .ORG zone.

No name server records were found.

and is probably hosted by AMAZON-02 - Amazon.com, Inc., US. See the full list of other websites hosted by AMAZON-02 - Amazon.com, Inc., US.

The highest website ck12.org position in Alexa rank database was 16442 and the lowest rank position was 18374. Current position of ck12.org in Alexa rank database is 18269.

Desktop speed score of ck12.org (74/100) is better than the results of 57.94% of other sites and shows that the page desktop performance can be improved.

Mobile usability score of ck12.org (99/100) is better than the results of 79.46% of other sites and means that the page is mobile-friendly.

Mobile speed score of ck12.org (49/100) is better than the results of 31.99% of other sites and shows that the landing page performance on mobile devices is poor and can be improved.

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ck12.org Alexa Rank

The traffic rank is based on three months of aggregated historical traffic data from millions of Alexa Toolbar users and is a combined measure of page views and users.

ck12.org whois

WHOIS gives you the ability to lookup any generic domains to find out the registered domain holder. WHOIS database are provided for information purposes only. It allows the public to check whether a specific domain name is still available or not and to obtain information related to the registration records of existing domain names.

Domain Name: CK12.ORG
Registry Domain ID: D135194116-LROR
Registrar WHOIS Server: whois.networksolutions.com
Registrar URL: http://www.networksolutions.com
Updated Date: 2018-03-01T18:45:38Z
Creation Date: 2006-12-16T08:37:03Z
Registry Expiry Date: 2022-12-16T08:37:03Z
Registrar Registration Expiration Date:
Registrar: Network Solutions, LLC
Registrar IANA ID: 2
Registrar Abuse Contact Email: abuse@web.com
Registrar Abuse Contact Phone: +1.8003337680
Reseller:
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Registrant Organization:
Registrant State/Province: FL
Registrant Country: US
Name Server: NS-1136.AWSDNS-14.ORG
Name Server: NS-161.AWSDNS-20.COM
Name Server: NS-1687.AWSDNS-18.CO.UK
Name Server: NS-977.AWSDNS-58.NET
DNSSEC: unsigned
URL of the ICANN Whois Inaccuracy Complaint Form https://www.icann.org/wicf/)
>>> Last update of WHOIS database: 2021-04-25T13:18:10Z

ck12.org server information

Servers Location

ck12.org desktop page speed rank

Last tested: 2019-12-07

Desktop Speed Medium
74/100

ck12.org Desktop Speed Test Quick Summary


priority - 14Eliminate render-blocking JavaScript and CSS in above-the-fold content

Your page has 9 blocking script resources and 7 blocking CSS resources. This causes a delay in rendering your page.

Remove render-blocking JavaScript:

https://www.ck12.org/media/buildnumber.js
https://st3.ck12.org/media/build-20191119163938/ck…Build/header-bundle.js
https://st1.ck12.org/media/build-20191119163938/co…ser/outdatedbrowser.js
https://st3.ck12.org/media/build-20191119163938/co…ok-app/dist/vendors.js
https://st3.ck12.org/media/build-20191119163938/co…-book-app/dist/main.js
https://maps.googleapis.com/maps/api/js?libraries=…-_W52IfMDdflx93pWYDJB8
https://st2.ck12.org/media/build-20191119163938/dexterjs/dexterjs.min.js
https://st1.ck12.org/media/build-20191119163938/common/js/utils/globals.js
https://st1.ck12.org/media/build-20191119163938/co…ser/outdatedbrowser.js

Optimize CSS Delivery of the following:

https://st1.ck12.org/media/build-20191119163938/li…y-ui-1.8.17.custom.css
https://st2.ck12.org/media/build-20191119163938/common/css/master.css
https://st2.ck12.org/media/build-20191119163938/common/css/tangerine-ui.css
https://fonts.googleapis.com/css?family=Pacifico
https://st3.ck12.org/media/build-20191119163938/du…rnames/css/content.css
https://st3.ck12.org/media/build-20191119163938/co…utdatedbrowser.min.css
https://www.ck12.org/media/common/css/gtranslate.overrides.css

priority - 12Avoid landing page redirects

Your page has 3 redirects. Redirects introduce additional delays before the page can be loaded.

Avoid landing page redirects for the following chain of redirected URLs.

http://ck12.org/
https://ck12.org/
https://www.ck12.org/
https://www.ck12.org/student/

priority - 5Leverage browser caching

Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.

Leverage browser caching for the following cacheable resources:

https://www.ck12.org/dexter/record/event (expiration not specified)
https://www.ck12.org/media/buildnumber.js (60 seconds)
https://cdn.mxpnl.com/libs/mixpanel-2-latest.min.js (10 minutes)
https://www.google-analytics.com/gtm/js?id=GTM-MJH…d=362991446.1575762933 (15 minutes)
https://www.googletagmanager.com/gtm.js?id=GTM-NFJ3V2 (15 minutes)
https://maps.googleapis.com/maps/api/js?libraries=…-_W52IfMDdflx93pWYDJB8 (30 minutes)
https://translate.googleapis.com/translate_static/css/translateelement.css (60 minutes)
https://translate.googleapis.com/translate_static/js/element/main.js (60 minutes)
https://www.google-analytics.com/plugins/ua/linkid.js (60 minutes)
https://www.google-analytics.com/analytics.js (2 hours)

priority - 2Prioritize visible content

Your page requires additional network round trips to render the above-the-fold content. For best performance, reduce the amount of HTML needed to render above-the-fold content.

The entire HTML response was not sufficient to render the above-the-fold content. This usually indicates that additional resources, loaded after HTML parsing, were required to render above-the-fold content. Prioritize visible content that is needed for rendering above-the-fold by including it directly in the HTML response.

None of the final above-the-fold content could be rendered even with the full HTML response.

priority - 0Minify HTML

Compacting HTML code, including any inline JavaScript and CSS contained in it, can save many bytes of data and speed up download and parse times.

Minify HTML for the following resources to reduce their size by 1.2KiB (18% reduction).

Minifying https://www.ck12.org/student/ could save 1.2KiB (18% reduction) after compression.

priority - 0Minify CSS

Compacting CSS code can save many bytes of data and speed up download and parse times.

Minify CSS for the following resources to reduce their size by 971B (17% reduction).

Minifying https://st1.ck12.org/media/build-20191119163938/li…y-ui-1.8.17.custom.css could save 737B (15% reduction) after compression.
Minifying https://www.ck12.org/media/common/css/gtranslate.overrides.css could save 129B (29% reduction) after compression.
Minifying https://st3.ck12.org/media/build-20191119163938/co…utdatedbrowser.min.css could save 105B (21% reduction) after compression.

priority - 0Minify JavaScript

Compacting JavaScript code can save many bytes of data and speed up downloading, parsing, and execution time.

Minify JavaScript for the following resources to reduce their size by 597B (33% reduction).

Minifying https://st1.ck12.org/media/build-20191119163938/co…ser/outdatedbrowser.js could save 597B (33% reduction) after compression.

priority - 0Optimize images

Properly formatting and compressing images can save many bytes of data.

Optimize the following images to reduce their size by 591B (42% reduction).

Compressing https://translate.googleapis.com/translate_static/img/te_ctrl3.gif could save 591B (42% reduction).

priority - 0Enable compression

Compressing resources with gzip or deflate can reduce the number of bytes sent over the network.

Enable compression for the following resources to reduce their transfer size by 373B (44% reduction).

Compressing https://bf29222dxw.bf.dynatrace.com/bf?type=js&ses…9&app=717c68634dfb8989 could save 373B (44% reduction).

ck12.org Desktop Resource Breakdown

Total Resources51
Number of Hosts23
Static Resources34
JavaScript Resources25
CSS Resources8

ck12.org mobile page speed rank

Last tested: 2017-05-31

Mobile Speed Bad
49/100

ck12.org Mobile Speed Test Quick Summary


priority - 64Eliminate render-blocking JavaScript and CSS in above-the-fold content

Your page has 4 blocking script resources and 7 blocking CSS resources. This causes a delay in rendering your page.

Remove render-blocking JavaScript:

https://cdn.amp.ai/ck12/sync-includes/production.js
https://st2.ck12.org/media/build-20170519151546/dexterjs/dexterjs.min.js
https://st1.ck12.org/media/build-20170519151546/common/js/utils/globals.js
https://st3.ck12.org/media/build-20170519151546/co…r/requirejs/require.js

Optimize CSS Delivery of the following:

https://st2.ck12.org/media/build-20170519151546/common/css/master.css
https://st3.ck12.org/media/build-20170519151546/du…rnames/css/content.css
https://st2.ck12.org/media/build-20170519151546/css/landing.css
https://st3.ck12.org/media/build-20170519151546/co…jquery.appdownload.css
https://st3.ck12.org/media/build-20170519151546/carousel/css/carousel.css
https://dvninqhj78q4x.cloudfront.net/media/common/…ranslate.overrides.css
https://translate.googleapis.com/translate_static/css/translateelement.css

priority - 34Avoid landing page redirects

Your page has 2 redirects. Redirects introduce additional delays before the page can be loaded.

Avoid landing page redirects for the following chain of redirected URLs.

http://ck12.org/
https://ck12.org/
https://www.ck12.org/

priority - 8Prioritize visible content

Your page requires additional network round trips to render the above-the-fold content. For best performance, reduce the amount of HTML needed to render above-the-fold content.

The entire HTML response was not sufficient to render the above-the-fold content. This usually indicates that additional resources, loaded after HTML parsing, were required to render above-the-fold content. Prioritize visible content that is needed for rendering above-the-fold by including it directly in the HTML response.

Only about 68% of the final above-the-fold content could be rendered with the full HTML response.

priority - 8Leverage browser caching

Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.

Leverage browser caching for the following cacheable resources:

https://static.ck12.org/images/elementary-science-…ementary-science_1.svg (expiration not specified)
https://www.ck12.org/dexter/get/trending/concepts (expiration not specified)
https://www.ck12.org/dexter/record/event (expiration not specified)
https://assets.zendesk.com/embeddable_framework/main.js (60 seconds)
https://cdn.amp.ai/ck12/sync-includes/production.js (5 minutes)
https://www.googletagmanager.com/gtm.js?id=GTM-NFJ3V2 (15 minutes)
https://apis.google.com/js/platform.js (30 minutes)
https://translate.googleapis.com/translate_static/css/translateelement.css (60 minutes)
https://translate.googleapis.com/translate_static/js/element/main.js (60 minutes)
https://www.google-analytics.com/plugins/ua/linkid.js (60 minutes)
https://www.google-analytics.com/analytics.js (2 hours)

priority - 1Optimize images

Properly formatting and compressing images can save many bytes of data.

Optimize the following images to reduce their size by 7KiB (46% reduction).

Compressing and resizing https://img1.ck12.org/media/build-20170519151546/c…/google-play-badge.png could save 4.9KiB (57% reduction).
Compressing https://img2.ck12.org/media/build-20170519151546/common/images/1x1.gif could save 1KiB (93% reduction).
Compressing https://st2.ck12.org/media/common/images/app_bck.gif could save 604B (22% reduction).
Compressing https://www.ck12.org/media/common/images/Scroll_Down.png could save 542B (18% reduction).

priority - 0Enable compression

Compressing resources with gzip or deflate can reduce the number of bytes sent over the network.

Enable compression for the following resources to reduce their transfer size by 4.2KiB (56% reduction).

Compressing https://d31qbv1cthcecs.cloudfront.net/atrk.js could save 2.2KiB (61% reduction).
Compressing https://static.ck12.org/images/elementary-science-…ementary-science_1.svg could save 1.4KiB (56% reduction).
Compressing https://t2901500.omkt.co/fp/r.js could save 546B (42% reduction).

priority - 0Minify JavaScript

Compacting JavaScript code can save many bytes of data and speed up downloading, parsing, and execution time.

Minify JavaScript for the following resources to reduce their size by 3.2KiB (38% reduction).

Minifying https://st3.ck12.org/media/build-20170519151546/co…/jquery.appdownload.js could save 2.6KiB (42% reduction) after compression.
Minifying https://st3.ck12.org/media/build-20170519151546/js/flxweb.settings.js could save 622B (29% reduction) after compression.

priority - 0Minify HTML

Compacting HTML code, including any inline JavaScript and CSS contained in it, can save many bytes of data and speed up download and parse times.

Minify HTML for the following resources to reduce their size by 2.3KiB (17% reduction).

Minifying https://www.ck12.org/ could save 2.3KiB (17% reduction) after compression.

ck12.org Mobile Resource Breakdown

Total Resources117
Number of Hosts27
Static Resources97
JavaScript Resources41
CSS Resources7

ck12.org mobile page usability

Last tested: 2017-05-31

Mobile Usability Good
99/100

ck12.org Mobile Usability Test Quick Summary


priority - 0Size tap targets appropriately

Some of the links/buttons on your webpage may be too small for a user to easily tap on a touchscreen. Consider making these tap targets larger to provide a better user experience.

The following tap targets are close to other nearby tap targets and may need additional spacing around them.

The tap target <a href="/analysis/Sums…nding_concepts" class="trending-conce…g-concept-item">Sums of Finite…ometric Series</a> and 2 others are close to other tap targets.

The tap target <button class="supportButton">Support</button> is close to 2 other tap targets.

The tap target <a id="apple-store-link" href="https://itunes…3639?ls=1&amp;mt=8"></a> is close to 1 other tap targets.

ck12.org HTML validation

Errors

Attribute “itemprop” not allowed on element “meta” at this point.

Line: 9 Column: 5 - 93
"...itle> <meta property="og:site_name" itemprop="name" name="author" content="CK-12 Foundation" /> <..."

Bad value “x-dns-prefetch-control” for attribute “http-equiv” on element “meta”.

Line: 15 Column: 5 - 59
"...s --> <meta http-equiv="x-dns-prefetch-control" content="on"> ..."

Bad start tag in “img” in “head”.

Line: 80 Column: 15 - 145
"...<noscript><img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" /></nosc..."

Stray end tag “noscript”.

Line: 80 Column: 146 - 156
"... alt="" /></noscript> <..."

Stray end tag “head”.

Line: 82 Column: 1 - 7
"...cript --> </head> <body..."

Start tag “body” seen but an element of the same type was already open.

Line: 83 Column: 1 - 15
"...> </head> <body class=""> ..."

Cannot recover after last error. Any further errors will be ignored.

Line: 83 Column: 1 - 15
"...> </head> <body class=""> ..."

Warnings

The “type” attribute is unnecessary for JavaScript resources.

Line: 76 Column: 5 - 35
"...t --> <script type="text/javascript"> _..."

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ck12.org Ping

Ping is a computer network administration software utility used to test the reachability of a host on an Internet Protocol (IP) network. It measures the round-trip time for messages sent from the originating host to a destination computer that are echoed back to the source.

ck12.org TRACEROUTE

Traceroute is a computer network diagnostic tool for displaying the route (path) and measuring transit delays of packets across an Internet Protocol (IP) network. The history of the route is recorded as the round-trip times of the packets received from each successive host (remote node) in the route (path); the sum of the mean times in each hop is a measure of the total time spent to establish the connection. Traceroute proceeds unless all (three) sent packets are lost more than twice, then the connection is lost and the route cannot be evaluated.