www.crossref.org speed test — 20 Oct 2026

Measured from the wfix.shop server on 20 October 2026 at 14:40 UTC. Grade B (84/100), with the screenshots, the timings and the fixes that matter.

https://www.crossref.org:443/

20 October 2026 at 14:40 UTC · Free test · report pt_1cc8f3428d09
Grade
B
84/100
Performance93/100
Structure70/100

9 audit(s) passed, 7 need work

First byte (TTFB)398 msmeasured from this server
Fully loaded1.90 sfirst byte + slowest asset
Requests26document + assets
Page weight423.3 KBcompressed transfer
HTML document9.3 KBgzip
ProtocolHTTP/3AmazonS3
Third-party91.1 KBother hosts

Where the first byte went

  • DNS lookup 61 ms 15%
  • TCP connect 81 ms 20%
  • Server wait 256 ms 64%

Measured on the connection that fetched the HTML. Every other request on the page waits for the end of this bar before it can start.

How this page compares

First bytefaster than 57% of 4,999 pages tested here398 ms against a median of 449 ms
Page weightlighter than 64% of 4,999 pages tested here423.3 KB against a median of 650.5 KB
Fully loadedslower than 53% of 4,999 pages tested here1.90 s against a median of 1.84 s
Requestssends more requests than 100% of 4,999 pages tested here26 against a median of 26

Every report published here is in this comparison, so it is a reference population of pages tested from one server - not a benchmark of the whole web.

What these numbers mean

  • The first byte arrived in 398 ms. That is workable, and the cheapest win left is caching or a warmer connection.
  • The page transfers 423.3 KB over 26 request(s). Images files are 56% of it, so resize and recompress the largest images before anything else.
  • The HTML itself arrives gzip-compressed.
  • It runs over HTTP/3, so the assets share a connection instead of opening one each.
  • 22% of the weight comes from other hosts (analytics, fonts, embeds), which also means their slow day becomes your slow day.
  • The largest element painted at 932 ms, inside the 2.5 s Google calls good.
  • Layout stayed still (CLS 0.013), so nothing jumps under the reader's cursor.
  • The main thread was blocked for 55 ms in total, which is not enough to feel.

Fix first: Render-blocking resources - Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.

Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.

Screenshot

What the page looks like

Loaded in headless Chromium on this server. Click an image to open it full size.

Desktop screenshot of www.crossref.org
Desktop 1366 × 768 · 785.4 KB · page is 1595 px tall
Mobile screenshot of www.crossref.org
Mobile 390 × 844 · 147.3 KB · page is 2919 px tall

Browser render

The same URL loaded in a real browser, so these are the readings curl cannot produce. The grade above is still built from the server measurements.

Largest contentful paint932 msgood is under 2.5 s
Cumulative layout shift0.013under 0.1 is stable
Total blocking time55 mslong tasks during load
First contentful paint660 msfirst content on screen
Browser page weight1.77 MB56 request(s), scripts included
Largest contentful paint932 ms
Goodgood under 2.5 s, poor over 4 s
Cumulative layout shift0.013
Goodgood under 0.1, poor over 0.25
Total blocking time55 ms
Goodgood under 200 ms, poor over 600 ms

Page weight by type

What the page is made of

Images 9 requests
237.1 KB 56%
Javascript 16 requests
177.0 KB 42%

Transfer size, compressed as sent. 26 request(s) in total, 423.3 KB across all of them.

Top issues

Render-blocking resources

high impact

10 render-blocking resource(s) in the document head (2 script(s), 8 stylesheet(s)). The page cannot paint until each one arrives.

Fix: Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.

Image delivery and format

medium impact

0 image(s) over 200 KB and 1 large image(s) still served as JPEG or PNG.

Fix: Serve WebP or AVIF with a JPEG fallback, size images to the space they occupy, and lazy-load anything below the fold. Images are usually more than half of a slow page.

Cache static assets

medium impact

18 asset(s) answer without a Cache-Control max-age, so browsers revalidate them on every visit.

Fix: Version filenames on change and serve them with a long max-age plus immutable. That is what makes a returning visitor fast.

Avoid extra redirects

medium impact

1 redirect hop(s) before the page load started, each one a full round trip before the first byte.

Fix: Link to the canonical URL (and make sure http, the apex domain and www all point at it) so no visitor pays a redirect first.

Mobile viewport

medium impact

No viewport meta tag, so a phone renders the desktop layout scaled down.

Fix: Add a viewport meta tag with width=device-width and an initial scale of 1.

Waterfall

Slowest requests

IMAGEScrossref.matomo.cloud/piwik.php
1.50 s
IMAGESassets.crossref.org/logo/crossref-logo-200.svg
1.42 s
JAVASCRIPTcdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.js
1.36 s
JAVASCRIPTwww.crossref.org/js/jquery.sticky-kit.min.js
1.23 s
IMAGESwww.crossref.org/img/crossref-love-metadata.svg
1.21 s
IMAGESwww.crossref.org/images/footer/cc.svg
1.21 s
IMAGESwww.crossref.org//images/staff/luis-montilla-thumb.jpg
1.21 s
IMAGESwww.crossref.org//img/crossref-logo-reverse.svg
1.21 s
IMAGESwww.crossref.org//images/staff/lucy-ofiesh.jpg
1.21 s
JAVASCRIPTcdn.datatables.net/1.10.16/js/jquery.dataTables.min.js
1.20 s

Each bar is one request's own response time, scaled to the slowest. Assets were fetched in parallel, so the bars overlap in real time rather than stacking. first party third party

RequestTypeStatusTimeSize
https://crossref.matomo.cloud/piwik.php?idsite=1&rec=1 3rd partyimages2001.50 s43 B
https://assets.crossref.org/logo/crossref-logo-200.svg 3rd partyimages2001.42 s3.0 KB
https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.js 3rd partyjavascript2001.36 s18.3 KB
https://www.crossref.org/js/jquery.sticky-kit.min.jsjavascript2001.23 s2.7 KB
https://www.crossref.org/img/crossref-love-metadata.svgimages2001.21 s7.7 KB
https://www.crossref.org:443/images/footer/cc.svgimages2001.21 s1.3 KB
https://www.crossref.org//images/staff/luis-montilla-thumb.jpgimages2001.21 s3.9 KB
https://www.crossref.org//img/crossref-logo-reverse.svgimages2001.21 s1.1 KB
https://www.crossref.org//images/staff/lucy-ofiesh.jpgimages2001.21 s177.8 KB
https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js 3rd partyjavascript2001.20 s26.0 KB
https://www.crossref.org/js/bootstrap.min.jsjavascript2001.20 s9.7 KB
https://www.crossref.org/js/crossref.js?v=1javascript2001.20 s9.0 KB
https://www.crossref.org/js/jquery.min.jsjavascript2001.20 s29.4 KB
https://www.crossref.org//images/staff/martyn-rittman.jpgimages2001.19 s41.3 KB
https://www.crossref.org:443/images/footer/by.svgimages2001.19 s912 B
https://www.crossref.org/js/jquery.ui-min.jsjavascript2001.19 s8.1 KB
https://cdnjs.cloudflare.com/ajax/libs/masonry/4.1.0/masonry.pkgd.js 3rd partyjavascript2001.19 s13.1 KB
https://www.crossref.org/js/jquery.validate.jsjavascript2001.17 s12.2 KB
https://www.crossref.org/js/jquery.cookiebar.jsjavascript2001.17 s2.5 KB
https://www.crossref.org/js/jquery.fancybox.jsjavascript2001.17 s13.8 KB
https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.js 3rd partyjavascript2001.16 s5.5 KB
https://www.crossref.org/js/js.cookie.jsjavascript2001.16 s1.4 KB
https://cdn.datatables.net/buttons/1.5.1/js/buttons.html5.min.js 3rd partyjavascript2001.16 s5.8 KB
https://cdn.jsdelivr.net/algoliasearch/3/algoliasearch.min.js 3rd partyjavascript2001.14 s18.9 KB
https://status.crossref.org/embed/script.js 3rd partyjavascript2001.14 s572 B
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