Editing Link rot (section)

== Prevalence ==
A number of studies have examined the prevalence of link rot within the [[World Wide Web]], in academic literature that uses [[URL]]s to cite web content, and within [[digital library|digital libraries]].

In a 2023 study of the [[The Million Dollar Homepage|Million Dollar Homepage]] external links, it was found that 27% of the links resulted in a site loading with no redirects, 45% of links have been redirected, and 28% returned various error messages.<ref>{{Cite web |last=Szymura |first=Sav |date=2023-09-11 |title=Link rot: what is it and how can I prevent it? |url=https://wolfenden.agency/insights/link-rot-what-is-it-and-how-can-i-prevent-it/ |access-date=2024-08-02 |website=Wolfenden |language=en}}</ref>

A 2002 study suggested that link rot within digital libraries is considerably slower than on the web. The article found that about 3% of the objects were no longer accessible after one year,<ref name=Nelson2002>{{cite journal | first1 = Michael L. | last1 = Nelson | first2 = B. Danette | last2 = Allen | year = 2002 | title = Object Persistence and Availability in Digital Libraries | doi = 10.1045/january2002-nelson | journal = D-Lib Magazine | volume = 8 | issue = 1 | url = https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1008&context=computerscience_fac_pubs | doi-access = free | access-date = 2019-09-24 | archive-date = 2020-07-19 | archive-url = https://web.archive.org/web/20200719044311/https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1008&context=computerscience_fac_pubs | url-status = live }}</ref> equating to a [[half-life]] of nearly 23 years.

A 2003 study found that on the Web, about one link out of every 200 broke each week,<ref name=Fetterly2003>{{cite conference | first1 = Dennis | last1 = Fetterly | first2 = Mark | last2 = Manasse | first3 = Marc | last3 = Najork | first4 = Janet | last4 = Wiener | year = 2003 | title = A large-scale study of the evolution of web pages | url = http://www2003.org/cdrom/papers/refereed/p097/P97%20sources/p97-fetterly.html | book-title = Proceedings of the 12th international conference on World Wide Web | access-date = 14 September 2010 | conference =  | archive-date = 9 July 2011 | archive-url = https://web.archive.org/web/20110709175020/http://www2003.org/cdrom/papers/refereed/p097/P97%20sources/p97-fetterly.html | url-status = live }}</ref> suggesting a [[half-life]] of 138 weeks. This rate was largely confirmed by a 2016–2017 study of links in [[Yahoo! Directory]] (which had stopped updating in 2014 after 21 years of development) that found the half-life of the directory's links to be two years.<ref>{{cite web |last=van der Graaf |first=Hans |title=The half-life of a link is two year |url=http://blog.zomdir.com/2017/10/the-half-life-of-link-is-two-year.html |website=ZOMDir's blog |access-date=2019-01-31 |url-status=live |archive-url=https://web.archive.org/web/20171017041901/http://blog.zomdir.com/2017/10/the-half-life-of-link-is-two-year.html |archive-date=2017-10-17}}</ref>

A 2004 study showed that subsets of Web links (such as those targeting specific file types or those hosted by academic institutions) could have dramatically different half-lives.<ref name=Koehler2004>{{cite journal | first = Wallace | last = Koehler | year = 2004 | title = A longitudinal study of web pages continued: a consideration of document persistence | url = http://www.informationr.net/ir/9-2/paper174.html | journal = Information Research | volume = 9 | issue = 2 | access-date = 2019-01-31 | archive-url = https://web.archive.org/web/20170911062629/http://www.informationr.net/ir/9-2/paper174.html | archive-date = 2017-09-11 | url-status = live}}</ref> The URLs selected for publication appear to have greater longevity than the average URL. A 2015 study by Weblock analyzed more than 180,000 links from references in the full-text corpora of three major open access publishers and found a half-life of about 14 years,<ref>{{cite web | title = All-Time Weblock Report | date = August 2015 | url = https://weblock.io/report?id=all | access-date = 12 January 2016 | url-status = dead | archive-url = https://web.archive.org/web/20160304081204/https://weblock.io/report?id=all | archive-date = 4 March 2016}}</ref> generally confirming a 2005 study that found that half of the [[Uniform Resource Locator|URLs]] cited in ''[[D-Lib Magazine]]'' articles were active 10 years after publication.<ref name=McCown2005>{{cite conference | first1 = Frank | last1 = McCown | first2 = Sheffan | last2 = Chan | first3 = Michael L. | last3 = Nelson | first4 = Johan | last4 = Bollen | year = 2005 | title = The Availability and Persistence of Web References in D-Lib Magazine | url = http://www.iwaw.net/05/papers/iwaw05-mccown1.pdf | url-status = dead | book-title = Proceedings of the 5th International Web Archiving Workshop and Digital Preservation (IWAW'05) | access-date = 2005-10-12 | archive-url = https://web.archive.org/web/20120717000118/http://www.iwaw.net/05/papers/iwaw05-mccown1.pdf | archive-date = 2012-07-17 }}</ref> Other studies have found higher rates of link rot in academic literature but typically suggest a half-life of four years or greater.<ref name=Spinellis2003>{{cite journal | author-link = Diomidis Spinellis | first = Diomidis | last = Spinellis | year = 2003 | title = The Decay and Failures of Web References | url = http://www.spinellis.gr/pubs/jrnl/2003-CACM-URLcite/html/urlcite.html | journal = Communications of the ACM | volume = 46 | issue = 1 | pages = 71–77 | doi = 10.1145/602421.602422 | citeseerx = 10.1.1.12.9599 | s2cid = 17750450 | access-date = 2007-09-29 | archive-date = 2020-07-23 | archive-url = https://web.archive.org/web/20200723030709/https://www.spinellis.gr/pubs/jrnl/2003-CACM-URLcite/html/urlcite.html | url-status = live }}</ref><ref name=Lawrence2001>{{Cite Q | Q21012586 }}</ref> A 2013 study in ''[[BMC Bioinformatics]]'' analyzed nearly 15,000 links in abstracts from Thomson Reuters's [[Web of Science]] citation index and found that the median lifespan of web pages was 9.3 years, and just 62% were archived.<ref>{{Cite journal | last1 = Hennessey | first1 = Jason | last2 = Xijin Ge | first2 = Steven | title = A Cross Disciplinary Study of Link Decay and the Effectiveness of Mitigation Techniques | journal = BMC Bioinformatics | volume = 14 | pages = S5 | date = 2013 | issue = Suppl 14 | doi = 10.1186/1471-2105-14-S14-S5 | pmid = 24266891 | pmc = 3851533 | doi-access = free }}</ref> A 2021 study of external links in ''[[New York Times]]'' articles published between 1996 and 2019 found a half-life of about 15 years (with significant variance among content topics) but noted that 13% of functional links no longer lead to the original content—a phenomenon called ''content drift''.<ref>{{Cite web|title=What the ephemerality of the Web means for your hyperlinks|url=https://www.cjr.org/analysis/linkrot-content-drift-new-york-times.php|access-date=2021-08-02|website=Columbia Journalism Review|language=en|archive-date=2021-08-02|archive-url=https://web.archive.org/web/20210802134941/https://www.cjr.org/analysis/linkrot-content-drift-new-york-times.php|url-status=live}}</ref>

A 2013 study found that 49% of links in U.S. Supreme court opinions are dead.<ref>{{Cite web |last=Garber |first=Megan |date=2013-09-23 |title=49% of the Links Cited in Supreme Court Decisions Are Broken |url=https://www.theatlantic.com/technology/archive/2013/09/49-of-the-links-cited-in-supreme-court-decisions-are-broken/279901/ |access-date=2024-01-10 |website=The Atlantic |language=en}}</ref>

A 2023 study looking at United States [[COVID-19]] dashboards found that 23% of the state dashboards available in February 2021 were no longer available at the previous URLs in April 2023.<ref name="Adams1">{{cite journal |last1=Adams |first1=Aaron M. |last2=Chen |first2=Xiang |last3=Li |first3=Weidong |last4=Chuanrong |first4=Zhang |title=Normalizing the pandemic: exploring the cartographic issues in state government COVID-19 dashboards |journal=Journal of Maps |date=27 July 2023 |volume=19 |issue=5 |pages=1–9 |doi=10.1080/17445647.2023.2235385|doi-access=free |bibcode=2023JMaps..19Q...1A }}</ref>

[[Pew Research Center|Pew Research]] found that, in 2023, 38% of pages from 2013 went missing. Also, in 2023, 54% of [[English Wikipedia]] articles had a dead link in the 'references' section and 23% of [[Article (publishing)|news articles]] linked to a dead URL.<ref>{{Cite web |last1=Chapekis |first1=Athena |last2=Bestvater |first2=Samuel |last3=Remy |first3=Emma |last4=Rivero |first4=Gonzalo |date=May 17, 2024 |title=When Online Content Disappears |url=https://www.pewresearch.org/data-labs/2024/05/17/when-online-content-disappears/ |access-date=May 19, 2024 |publisher=[[Pew Research Center]]}}</ref>