Tools & Wizards About Us
bibliotheek.leidenuniv.nl screenshot

Report Summary

  • 38

    Performance

    Renders faster than
    57% of other websites

  • 88

    Accessibility

    Visual factors better than
    that of 68% of websites

  • 83

    Best Practices

    More advanced features
    available than in
    55% of websites

  • 99

    SEO

    Google-friendlier than
    93% of websites

bibliotheek.leidenuniv.nl

Universitaire Bibliotheken Leiden - Universiteit Leiden

Page Load Speed

4.2 sec in total

First Response

376 ms

Resources Loaded

3.6 sec

Page Rendered

295 ms

bibliotheek.leidenuniv.nl screenshot

About Website

Visit bibliotheek.leidenuniv.nl now to see the best up-to-date Bibliotheek Leiden Univ content for Netherlands and also check out these interesting facts you probably never knew about bibliotheek.leidenuniv.nl

De Universitaire Bibliotheken Leiden (UBL) is een internationaal toonaangevende wetenschappelijke bibliotheek met collecties van wereldformaat en met geavanceerde diensten voor onderwijs en onderzoek....

Visit bibliotheek.leidenuniv.nl

Key Findings

We analyzed Bibliotheek.leidenuniv.nl page load time and found that the first response time was 376 ms and then it took 3.8 sec to load all DOM resources and completely render a web page. This is a poor result, as 65% of websites can load faster.

Performance Metrics

bibliotheek.leidenuniv.nl performance score

38

Measured Metrics

name

value

score

weighting

FCP (First Contentful Paint)

Value3.1 s

46/100

10%

LCP (Largest Contentful Paint)

Value5.4 s

20/100

25%

SI (Speed Index)

Value12.3 s

3/100

10%

TBT (Total Blocking Time)

Value250 ms

84/100

30%

CLS (Cumulative Layout Shift)

Value0.493

17/100

15%

TTI (Time to Interactive)

Value19.0 s

3/100

10%

Network Requests Diagram

bibliotheek.leidenuniv.nl

376 ms

bibliotheek.leidenuniv.nl

457 ms

www.bibliotheek.universiteitleiden.nl

584 ms

screen.css

279 ms

js

55 ms

Our browser made a total of 39 requests to load all elements on the main page. We found that 5% of them (2 requests) were addressed to the original Bibliotheek.leidenuniv.nl, 82% (32 requests) were made to Bibliotheek.universiteitleiden.nl and 5% (2 requests) were made to Digitalscholarshipleiden.nl. The less responsive or slowest element that took the longest time to load (1.8 sec) relates to the external source Bibliotheek.universiteitleiden.nl.

Page Optimization Overview & Recommendations

Page size can be reduced by 25.2 kB (72%)

Content Size

35.1 kB

After Optimization

9.9 kB

  • HTML
  • Images

In fact, the total size of Bibliotheek.leidenuniv.nl main page is 35.1 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. 20% of websites need less resources to load. HTML takes 31.1 kB which makes up the majority of the site volume.

HTML Optimization

-81%

Potential reduce by 25.2 kB

  • Original 31.1 kB
  • After minification 24.4 kB
  • After compression 5.9 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 6.8 kB, which is 22% 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 25.2 kB or 81% of the original size.

Image Optimization

-0%

Potential reduce by 0 B

  • Original 4.0 kB
  • After minification 4.0 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. Bibliotheek Leiden Univ images are well optimized though.

Requests Breakdown

Number of requests can be reduced by 13 (39%)

Requests Now

33

After Optimization

20

  • AJAX
  • Images
  • JavaScript
  • CSS

The browser has sent 33 CSS, Javascripts, AJAX and image requests in order to completely render the main page of Bibliotheek Leiden Univ. We recommend that multiple CSS and JavaScript files should be merged into one by each type, as it can help reduce assets requests from 14 to 1 for JavaScripts and as a result speed up the page load time.

Network Requests Diagram

bibliotheek.leidenuniv.nl

bibliotheek.leidenuniv.nl

376 ms

bibliotheek.leidenuniv.nl

bibliotheek.leidenuniv.nl

457 ms

www.bibliotheek.universiteitleiden.nl

www.bibliotheek.universiteitleiden.nl

584 ms

screen.css

screen.css

279 ms

js

js

55 ms

ul2.js

ul2.js

334 ms

zegel.png

zegel.png

163 ms

homepage-header_students_in_a_library.jpg

homepage-header_students_in_a_library.jpg

463 ms

studeren-in-de-bibliotheek-3x1.jpg

studeren-in-de-bibliotheek-3x1.jpg

194 ms

c_onderzoeker_blokje_3x1-copy.jpg

c_onderzoeker_blokje_3x1-copy.jpg

475 ms

homepage-blokje.jpg

homepage-blokje.jpg

1026 ms

cds_banner_3x1-copy.jpg

cds_banner_3x1-copy.jpg

496 ms

wandschildering-van-anton-de-kom-500-x-167copy.png

wandschildering-van-anton-de-kom-500-x-167copy.png

1835 ms

blokje-homepage-te-zien-en-te-doen-3x1.jpg

blokje-homepage-te-zien-en-te-doen-3x1.jpg

291 ms

d50x50

d50x50

398 ms

d50x50

d50x50

497 ms

d50x50

d50x50

558 ms

world-map.png

world-map.png

538 ms

vestulapro-semibold.woff

vestulapro-semibold.woff

536 ms

vestulapro-regular.woff

vestulapro-regular.woff

428 ms

fontello.woff

fontello.woff

491 ms

jquery.js

jquery.js

529 ms

main.js

main.js

95 ms

picturefill.js

picturefill.js

97 ms

ajax.js

ajax.js

95 ms

box-more.js

box-more.js

96 ms

nav.js

nav.js

108 ms

search.js

search.js

204 ms

suggest.js

suggest.js

209 ms

track-event.js

track-event.js

210 ms

local-search.js

local-search.js

210 ms

xsltblock

xsltblock

199 ms

xsltblock

xsltblock

204 ms

blog

blog

210 ms

opening-hours.js

opening-hours.js

96 ms

load_chat.php

load_chat.php

397 ms

file-02_generated_2024-06-18-092400_arki.jpg

file-02_generated_2024-06-18-092400_arki.jpg

690 ms

a_banner_Or.650-leather_block-stamped-copy.jpg

a_banner_Or.650-leather_block-stamped-copy.jpg

693 ms

pexels-fauxels-3183197.jpg

pexels-fauxels-3183197.jpg

693 ms

Accessibility Review

bibliotheek.leidenuniv.nl accessibility score

88

Accessibility Issues

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

Buttons do not have an accessible name

High

Links do not have a discernible name

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.

Best Practices

bibliotheek.leidenuniv.nl 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

Page has valid source maps

SEO Factors

bibliotheek.leidenuniv.nl SEO score

99

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

    NL

  • Language Claimed

    NL

  • Encoding

    UTF-8

Language claimed in HTML meta tag should match the language actually used on the web page. Otherwise Bibliotheek.leidenuniv.nl can be misinterpreted by Google and other search engines. Our service has detected that Dutch is used on the page, and it matches the claimed language. Our system also found out that Bibliotheek.leidenuniv.nl 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

bibliotheek.leidenuniv.nl

Open Graph description is not detected on the main page of Bibliotheek Leiden Univ. 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: