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vdatum.noaa.gov screenshot

Report Summary

  • 65

    Performance

    Renders faster than
    78% of other websites

  • 86

    Accessibility

    Visual factors better than
    that of 61% of websites

  • 75

    Best Practices

    More advanced features
    available than in
    35% of websites

  • 92

    SEO

    Google-friendlier than
    74% of websites

vdatum.noaa.gov

NOAA/NOS's VDatum 4.6.1: Vertical Datums Transformation

Page Load Speed

680 ms in total

First Response

39 ms

Resources Loaded

457 ms

Page Rendered

184 ms

vdatum.noaa.gov screenshot

About Website

Click here to check amazing VDatum NOAA content for United States. Otherwise, check out these important facts you probably never knew about vdatum.noaa.gov

VDatum is designed to vertically transform geospatial data among a variety of tidal, orthometric and ellipsoidal vertical datums - allowing users to convert their data from different horizontal/vertic...

Visit vdatum.noaa.gov

Key Findings

We analyzed Vdatum.noaa.gov page load time and found that the first response time was 39 ms and then it took 641 ms to load all DOM resources and completely render a web page. This is quite a good result, as only 10% of websites can load faster.

Performance Metrics

vdatum.noaa.gov performance score

65

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.7 s

30/100

10%

LCP (Largest Contentful Paint)

Value7.1 s

5/100

25%

SI (Speed Index)

Value3.7 s

86/100

10%

TBT (Total Blocking Time)

Value50 ms

100/100

30%

CLS (Cumulative Layout Shift)

Value0

100/100

15%

TTI (Time to Interactive)

Value5.1 s

75/100

10%

Network Requests Diagram

vdatum.noaa.gov

39 ms

vdatum.css

9 ms

federated-analytics.js

23 ms

vdatum.js

20 ms

jquery-3.6.0.js

39 ms

Our browser made a total of 17 requests to load all elements on the main page. We found that 76% of them (13 requests) were addressed to the original Vdatum.noaa.gov, 12% (2 requests) were made to Googletagmanager.com and 12% (2 requests) were made to Ssl.google-analytics.com. The less responsive or slowest element that took the longest time to load (135 ms) relates to the external source Googletagmanager.com.

Page Optimization Overview & Recommendations

Page size can be reduced by 291.3 kB (36%)

Content Size

820.4 kB

After Optimization

529.1 kB

  • HTML
  • Images
  • JavaScript
  • CSS

In fact, the total size of Vdatum.noaa.gov main page is 820.4 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. 40% of websites need less resources to load. Images take 426.6 kB which makes up the majority of the site volume.

HTML Optimization

-74%

Potential reduce by 14.7 kB

  • Original 19.8 kB
  • After minification 15.3 kB
  • After compression 5.1 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 4.5 kB, which is 23% 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 14.7 kB or 74% of the original size.

Image Optimization

-3%

Potential reduce by 14.6 kB

  • Original 426.6 kB
  • After minification 412.0 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. VDatum NOAA images are well optimized though.

JavaScript Optimization

-70%

Potential reduce by 257.3 kB

  • Original 367.6 kB
  • After minification 333.1 kB
  • After compression 110.3 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 257.3 kB or 70% of the original size.

CSS Optimization

-75%

Potential reduce by 4.8 kB

  • Original 6.4 kB
  • After minification 4.9 kB
  • After compression 1.6 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. Vdatum.noaa.gov needs all CSS files to be minified and compressed as it can save up to 4.8 kB or 75% of the original size.

Requests Breakdown

Number of requests can be reduced by 5 (31%)

Requests Now

16

After Optimization

11

  • Images
  • JavaScript
  • CSS

The browser has sent 16 CSS, Javascripts, AJAX and image requests in order to completely render the main page of VDatum NOAA. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 6 to 1 for JavaScripts and as a result speed up the page load time.

Network Requests Diagram

vdatum.noaa.gov

vdatum.noaa.gov

39 ms

vdatum.css

vdatum.css

9 ms

federated-analytics.js

federated-analytics.js

23 ms

vdatum.js

vdatum.js

20 ms

jquery-3.6.0.js

jquery-3.6.0.js

39 ms

js

js

59 ms

js

js

135 ms

ga.js

ga.js

34 ms

background_top.jpg

background_top.jpg

99 ms

background_bottom.jpg

background_bottom.jpg

99 ms

background-mid.jpg

background-mid.jpg

78 ms

gototop.png

gototop.png

77 ms

noaa_left.png

noaa_left.png

112 ms

noaa_right.png

noaa_right.png

113 ms

seperator.gif

seperator.gif

117 ms

vdatum_overview_Tampav.gif

vdatum_overview_Tampav.gif

127 ms

__utm.gif

__utm.gif

39 ms

Accessibility Review

vdatum.noaa.gov accessibility score

86

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

Tables and lists

These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.

Impact

Issue

High

Lists do not contain only <li> elements and script supporting elements (<script> and <template>).

Best Practices

vdatum.noaa.gov best practices score

75

Areas of Improvement

Trust and Safety

Impact

Issue

High

Does not use HTTPS

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

SEO Factors

vdatum.noaa.gov SEO score

92

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

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 Vdatum.noaa.gov 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 Vdatum.noaa.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

vdatum.noaa.gov

Open Graph description is not detected on the main page of VDatum NOAA. 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: