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cdc.gov screenshot

Report Summary

  • 12

    Performance

    Renders faster than
    25% of other websites

  • 98

    Accessibility

    Visual factors better than
    that of 94% of websites

  • 92

    Best Practices

    More advanced features
    available than in
    81% of websites

  • 92

    SEO

    Google-friendlier than
    75% of websites

cdc.gov

Centers for Disease Control and Prevention

Page Load Speed

959 ms in total

First Response

41 ms

Resources Loaded

672 ms

Page Rendered

246 ms

cdc.gov screenshot

About Website

Click here to check amazing Cdc content for United States. Otherwise, check out these important facts you probably never knew about cdc.gov

CDC is the nation’s leading science-based, data-driven, service organization that protects the public’s health. For more than 70 years, we’ve put science into action to help children stay healthy so t...

Visit cdc.gov

Key Findings

We analyzed Cdc.gov page load time and found that the first response time was 41 ms and then it took 918 ms to load all DOM resources and completely render a web page. This is quite a good result, as only 15% of websites can load faster.

Performance Metrics

cdc.gov performance score

12

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.4 s

36/100

10%

LCP (Largest Contentful Paint)

Value12.0 s

0/100

25%

SI (Speed Index)

Value8.5 s

18/100

10%

TBT (Total Blocking Time)

Value1,810 ms

9/100

30%

CLS (Cumulative Layout Shift)

Value0.414

24/100

15%

TTI (Time to Interactive)

Value16.5 s

5/100

10%

Network Requests Diagram

cdc.gov

41 ms

www.cdc.gov

56 ms

bootstrap24.css

22 ms

app.css

10 ms

modernizr-latest.js

30 ms

Our browser made a total of 81 requests to load all elements on the main page. We found that 83% of them (67 requests) were addressed to the original Cdc.gov, 7% (6 requests) were made to Www2c.cdc.gov and 5% (4 requests) were made to Search.usa.gov. The less responsive or slowest element that took the longest time to load (252 ms) relates to the external source Www2c.cdc.gov.

Page Optimization Overview & Recommendations

Page size can be reduced by 1.3 MB (39%)

Content Size

3.3 MB

After Optimization

2.0 MB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Cdc.gov main page is 3.3 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. 70% of websites need less resources to load. Images take 1.7 MB which makes up the majority of the site volume.

HTML Optimization

-83%

Potential reduce by 57.7 kB

  • Original 69.7 kB
  • After minification 56.9 kB
  • After compression 12.0 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 12.8 kB, which is 18% 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 57.7 kB or 83% of the original size.

Image Optimization

-4%

Potential reduce by 72.2 kB

  • Original 1.7 MB
  • After minification 1.6 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. Cdc images are well optimized though.

JavaScript Optimization

-68%

Potential reduce by 599.3 kB

  • Original 887.0 kB
  • After minification 843.3 kB
  • After compression 287.7 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 599.3 kB or 68% of the original size.

CSS Optimization

-84%

Potential reduce by 546.6 kB

  • Original 648.2 kB
  • After minification 611.4 kB
  • After compression 101.5 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. Cdc.gov needs all CSS files to be minified and compressed as it can save up to 546.6 kB or 84% of the original size.

Requests Breakdown

Number of requests can be reduced by 40 (52%)

Requests Now

77

After Optimization

37

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 77 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Cdc. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 22 to 1 for JavaScripts and from 9 to 1 for CSS and as a result speed up the page load time.

Network Requests Diagram

cdc.gov

cdc.gov

41 ms

www.cdc.gov

www.cdc.gov

56 ms

bootstrap24.css

bootstrap24.css

22 ms

app.css

app.css

10 ms

modernizr-latest.js

modernizr-latest.js

30 ms

homepage.css

homepage.css

40 ms

yamm.css

yamm.css

42 ms

localrd.css

localrd.css

40 ms

libs.min.js

libs.min.js

63 ms

core.min.js

core.min.js

37 ms

app.min.js

app.min.js

37 ms

foresee-trigger.js

foresee-trigger.js

36 ms

foresee-variables.js

foresee-variables.js

60 ms

Universal-Federated-Analytics-Min.js

Universal-Federated-Analytics-Min.js

128 ms

rd_custom_interactions.js

rd_custom_interactions.js

129 ms

topic_levels.js

topic_levels.js

59 ms

s_code_v21_cdcgov.js

s_code_v21_cdcgov.js

131 ms

rd_search.js

rd_search.js

130 ms

homePageSurvey.js

homePageSurvey.js

150 ms

rss-featurefeed-disease.js

rss-featurefeed-disease.js

129 ms

rss-featurefeed-healthy.js

rss-featurefeed-healthy.js

145 ms

rss-featurefeed-travel.js

rss-featurefeed-travel.js

154 ms

rss-featurefeed-emergency.js

rss-featurefeed-emergency.js

138 ms

masthead.svg

masthead.svg

114 ms

masthead_3-col.svg

masthead_3-col.svg

111 ms

masthead_1-col.svg

masthead_1-col.svg

108 ms

homepage_gradient.jpg

homepage_gradient.jpg

99 ms

su.png

su.png

94 ms

sm-plus.gif

sm-plus.gif

94 ms

16_250322-bt_thapar_zika_general_2_v4_1184x300.jpg

16_250322-bt_thapar_zika_general_2_v4_1184x300.jpg

94 ms

zika_285px.jpg

zika_285px.jpg

174 ms

africanamericanhistory_285px.jpg

africanamericanhistory_285px.jpg

170 ms

getting-enough-sleep_285px.jpg

getting-enough-sleep_285px.jpg

169 ms

rawmilk_285px.jpg

rawmilk_285px.jpg

170 ms

outbreak_icon.png

outbreak_icon.png

172 ms

CDC_247.png

CDC_247.png

170 ms

cdc_24-7_horizontal.png

cdc_24-7_horizontal.png

174 ms

cdc-jobs_200px.jpg

cdc-jobs_200px.jpg

171 ms

cdc-jobs_450px.jpg

cdc-jobs_450px.jpg

170 ms

virus.jpg

virus.jpg

174 ms

organization.jpg

organization.jpg

172 ms

dr_frieden.jpg

dr_frieden.jpg

171 ms

TwitterFailoverButton.png

TwitterFailoverButton.png

172 ms

ss.png

ss.png

171 ms

sm.png

sm.png

177 ms

analytics.js

analytics.js

108 ms

lato-regular-webfont.woff

lato-regular-webfont.woff

105 ms

fontawesome-webfont.woff

fontawesome-webfont.woff

105 ms

feed.asp

feed.asp

84 ms

feed.asp

feed.asp

92 ms

feed.asp

feed.asp

252 ms

feed.asp

feed.asp

90 ms

feed.asp

feed.asp

89 ms

socialmenu.js

socialmenu.js

58 ms

socialmenu.css

socialmenu.css

50 ms

remote.loader.js

remote.loader.js

39 ms

feed.asp

feed.asp

33 ms

smRecommend.png

smRecommend.png

61 ms

smTweet.png

smTweet.png

74 ms

foresee-surveydef.js

foresee-surveydef.js

50 ms

facebook-32.png

facebook-32.png

42 ms

twitter-32.png

twitter-32.png

101 ms

collect

collect

48 ms

sayt.css

sayt.css

20 ms

sayt_loader_libs.js

sayt_loader_libs.js

39 ms

stats.js

stats.js

21 ms

cruiseshiptravel_456px.jpg

cruiseshiptravel_456px.jpg

69 ms

VFCProgram_456px.jpg

VFCProgram_456px.jpg

58 ms

winterweather_456px.jpg

winterweather_456px.jpg

49 ms

foresee-dhtml.css

foresee-dhtml.css

11 ms

s34313010289333

s34313010289333

83 ms

print.css

print.css

28 ms

addthis-32.png

addthis-32.png

6 ms

twitter-16.png

twitter-16.png

5 ms

facebook-16.png

facebook-16.png

14 ms

pinterest-16.png

pinterest-16.png

5 ms

linkedin-16.png

linkedin-16.png

5 ms

email-16.png

email-16.png

14 ms

digg-16.png

digg-16.png

13 ms

getting-enough-sleep_456px.jpg

getting-enough-sleep_456px.jpg

111 ms

ui-bg_flat_75_ffffff_40x100.png

ui-bg_flat_75_ffffff_40x100.png

31 ms

Accessibility Review

cdc.gov accessibility score

98

Accessibility Issues

Navigation

These are opportunities to improve keyboard navigation in your application.

Impact

Issue

High

[id] attributes on active, focusable elements are not unique

Best Practices

cdc.gov best practices score

92

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

Low

Ensure CSP is effective against XSS attacks

General

Impact

Issue

Low

Detected JavaScript libraries

High

Page has valid source maps

SEO Factors

cdc.gov SEO score

92

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 Cdc.gov 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 Cdc.gov 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

cdc.gov

Open Graph data is detected on the main page of Cdc. This is the best way to make the web page social media friendly. Here is how it looks like on Facebook: