Report Summary

  • 23

    Performance

    Renders faster than
    42% of other websites

  • 91

    Accessibility

    Visual factors better than
    that of 77% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    56% of websites

  • 97

    SEO

    Google-friendlier than
    91% of websites

libraryofcongress.gov

Home | Library of Congress

Page Load Speed

987 ms in total

First Response

24 ms

Resources Loaded

713 ms

Page Rendered

250 ms

libraryofcongress.gov screenshot

About Website

Click here to check amazing Library Of Congress content. Otherwise, check out these important facts you probably never knew about libraryofcongress.gov

The world's largest library. View historic photos, maps, books and more. Contact experts for help with research. Plan a visit. Home of U.S. Copyright Office.

Visit libraryofcongress.gov

Key Findings

We analyzed Libraryofcongress.gov page load time and found that the first response time was 24 ms and then it took 963 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

libraryofcongress.gov performance score

23

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value4.4 s

16/100

10%

LCP (Largest Contentful Paint)

Value21.8 s

0/100

25%

SI (Speed Index)

Value9.6 s

11/100

10%

TBT (Total Blocking Time)

Value1,070 ms

24/100

30%

CLS (Cumulative Layout Shift)

Value0.111

87/100

15%

TTI (Time to Interactive)

Value20.7 s

2/100

10%

Network Requests Diagram

libraryofcongress.gov

24 ms

www.loc.gov

61 ms

base.css

21 ms

jquery-1.8.2.min.js

60 ms

base.js

213 ms

Our browser made a total of 45 requests to load all elements on the main page. We found that 2% of them (1 request) were addressed to the original Libraryofcongress.gov, 89% (40 requests) were made to Loc.gov and 4% (2 requests) were made to Cdn.loc.gov. The less responsive or slowest element that took the longest time to load (405 ms) relates to the external source Loc.gov.

Page Optimization Overview & Recommendations

Page size can be reduced by 818.2 kB (46%)

Content Size

1.8 MB

After Optimization

949.2 kB

In fact, the total size of Libraryofcongress.gov 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. 60% of websites need less resources to load. Images take 751.1 kB which makes up the majority of the site volume.

HTML Optimization

-85%

Potential reduce by 95.0 kB

  • Original 111.4 kB
  • After minification 64.6 kB
  • After compression 16.4 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 46.8 kB, which is 42% 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 95.0 kB or 85% of the original size.

Image Optimization

-1%

Potential reduce by 4.2 kB

  • Original 751.1 kB
  • After minification 746.9 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. Library Of Congress images are well optimized though.

JavaScript Optimization

-75%

Potential reduce by 439.4 kB

  • Original 587.0 kB
  • After minification 522.1 kB
  • After compression 147.6 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 439.4 kB or 75% of the original size.

CSS Optimization

-88%

Potential reduce by 279.6 kB

  • Original 318.0 kB
  • After minification 255.8 kB
  • After compression 38.4 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. Libraryofcongress.gov needs all CSS files to be minified and compressed as it can save up to 279.6 kB or 88% of the original size.

Requests Breakdown

Number of requests can be reduced by 8 (19%)

Requests Now

42

After Optimization

34

The browser has sent 42 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Library Of Congress. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 4 to 1 for JavaScripts and as a result speed up the page load time.

Accessibility Review

libraryofcongress.gov accessibility score

91

Accessibility Issues

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.

Impact

Issue

High

[aria-hidden="true"] elements contain focusable descendents

High

[aria-*] attributes do not have valid values

Best Practices

libraryofcongress.gov best practices score

83

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

General

Impact

Issue

Low

Detected JavaScript libraries

High

Missing source maps for large first-party JavaScript

SEO Factors

libraryofcongress.gov SEO score

97

Search Engine Optimization Advices

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 Libraryofcongress.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 Libraryofcongress.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

Open Graph description is not detected on the main page of Library Of Congress. 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: