"ଉଇକିପିଡ଼ିଆ:Link rot" ପୃଷ୍ଠାର ସଂସ୍କରଣଗୁଡ଼ିକ ମଧ୍ୟରେ ତଫାତ
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ଟିକେ ଇଂରାଜୀ ଉଇଇପିଡ଼ିଆ ସହ ମେଳ କରାଗଲା |
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୧ କ ଧାଡ଼ି:
{{short description|Project page discussing issue of external pages going down over time, breaking links}}
{{about|(primarily) link rot in [[WP:External links|external links]]|broken section links within Wikipedia|Wikipedia:Database reports/Broken section anchors|internal links which point to deleted or non-existent articles|WP:REDLINKS|other uses|Wikipedia:Citing sources#Preventing and repairing dead links}}
{{redirect|WP:LR|Lua requests|Wikipedia:Lua requests}}
{{hatnote|To request URL changes, see [[WP:Link rot/URL change requests]].}}
{{Wikipedia how to|WP:LR|WP:404|WP:ROT|WP:BADLINK|WP:LINKROT|WP:DEADLINK}}
{{nutshell|Steps may be taken to reduce or repair dead external links.}}
Like most large [[website]]s, Wikipedia suffers from the phenomenon known as '''[[link rot]]''', where external links go dead (become '''[[WP:DEADREF|dead link]]s'''), as the linked web pages or complete websites disappear, change their content, or move. This presents a significant threat to Wikipedia's [[WP:RS|reliability]] policy and its [[Wikipedia:Citing sources|source citation]] guideline.
In general, do not delete cited information ''solely'' because the URL to the source does not work any longer. Tools, procedures, and processes are available as outlined in this document.
==Preventing link rot==
{{shortcut|WP:PLRT}}
===Automatic archiving===
Links added by editors to the English Wikipedia mainspace are automatically saved to [[Wayback Machine]] within about 24 hours (nb. in practice not every link is getting saved for various reasons). This is done with a program called [https://github.com/internetarchive/crawling-for-nomore404/tree/master/wikipedia/producer "NoMore404"] which Internet Archive runs and maintains; other language wiki sites are included. It scans the IRC feed channels, extracts new external URLs and adds a snapshot to the Wayback. This system became active sometime after 2015, though previous efforts were also made. Also, sometime after 2012, [[archive.today]] attempted to archive all external links then existing on Wikipedia at that time. This was incomplete but a significant number of links were added to archive.today during this period making it a major archival source filing in gaps of coverage. Archive.today is still making some automated archives as of 2020, though the extent of coverage and frequency is unknown.
As of 2015, there is a Wikipedia bot and tool called [[WP:IABOT]] that automates fixing link rot. It runs continuously checking all articles on Wikipedia if a link is dead, adding archives to [[Wayback Machine]] (if not yet there), and replacing dead links in the wikitext with an archived version. This bot runs automatically but it can also be directed by end users through its web interface. It is available when viewing any page's history, located near the top of the page on the line of "External Tools", with the "Fix dead links" option.
As of 2015, the periodic bot [[WP:WAYBACKMEDIC]] checks for link rot in the archive links themselves. Archive databases are dynamic and changing, archives go missing, move, new ones added etc.. this bot maintains existing archive links on English Wikipedia.
===Manual archiving===
Suggestions for ways to manually improve archiving:
* Avoid [[Wikipedia:Bare URLs|bare URLs]]. Use citation templates such as {{tlx|cite web}} for citations, and {{tlx|webarchive}} for external links sections.
* Use a [[web archiving]] service such as [[Internet Archive]] or [[Archive.is]]. A complete list is available at [[WP:List of web archives on Wikipedia]]. Within citation templates, put the archive URL in {{para|archive-url}} and add an {{para|archive-date}}. If the link is still valid, include {{para|url-status|live}}, otherwise set {{para|url-status|dead}}.
* If the link is still live but not yet archived, visit the web site of the archive service of your choice and request that the page be archived.
* Run [[WP:IABOT]] on pages via its user interface.
===Alternative methods===
Most [[Wikipedia:Citation templates|citation templates]] have a {{para|quote}} parameter that can be used to store text quotes of the source material. This can be used to store a limited amount of text from the source within the citation template. This is especially useful for sources that cannot be archived with web archiving services. It can also provide insurance against failure of the chosen web archiving service. Storing the entire text of the source is not appropriate under [[Wikipedia:Non-free content|fair use policies]], so choose only the most important portions of the text that most support the assertions in the Wikipedia article. Where applicable, [[Wikipedia:Public domain|public domain]] materials can be copied to [[Wikisource]].
==Repairing a dead link==
{{shortcut|WP:DEADLINK}}
{{Redirect|WP:DEADLINK|the guideline on what to do when a link is dead (including potential removal of the cited material)|WP:DEADREF}}
There are several ways to try to repair a dead link, detailed below:
===Searching===
If the dead link includes enough information (article title, names, etc.) it is often possible to use it to find the Web page at a different location, either on the same site or elsewhere.
Often web pages simply moved within the same site. A site index or site-specific search feature is a useful place to locate the moved page. If these tools are not available, many Internet search engines allow a search on a specified site.
Failing this, searching the Internet for the page can find alternatives.
If you find a suitable new URL, then you can edit the parameters within the citation. If the citation uses one of the common templates (e.g. {{template|cite web}}, {{template|cite news}}, {{template|Citation}}), then you can edit as follows:
* Change the {{para|url}} to point to the new URL;
* Change or add {{para|access-date}} to refer to the current date.
===Internet archives===
Check for archived versions at one of the many web archive services. The "Big 3" archive services are ''web.archive.org'', ''webcitation.org'' and ''archive.is''. These account for over 90% of all archives on Wikipedia, with ''web.archive.org'' being over 80% of all archive links. Other archive services are listed at [[WP:WEBARCHIVES]].
The [https://timetravel.mementoweb.org/ Mementos interface] allows one to search multiple archiving services with a single search. The Memento database is cached, meaning results are returned quickly, but the cache also becomes out of date. Therefore, it should not be relied on as the final word – very often when it reports no archives are available they actually are. You may still need to do the work of checking individual archive sites, but Mementos can be a quick first check.
<div style="overflow:auto;">
{| class="wikitable" style="margin: 1em auto 1em auto;"
|+ Bookmarklets to check common archive sites for archives of the current page<span style="font-weight:normal;"><br />(all open in a new tab or window)</span>
|-
! Archive site !! Bookmarklet
|-
| Archive.org || <syntaxhighlight lang="javascript">javascript:void(window.open('https://web.archive.org/web/*/'+location.href))</syntaxhighlight>
|-
| UKGWA || <syntaxhighlight lang="javascript">javascript:void(window.open('http://webarchive.nationalarchives.gov.uk/*/'+location.href))</syntaxhighlight>
|}</div>
If multiple archive dates are available, use the one that is most likely to be the contents of the page seen by the editor who entered the reference on the {{para|access-date}}. If that parameter is not specified, a [http://wikipedia.ramselehof.de/wikiblame.php?lang=en search of the article's revision history] can be performed to determine when the link was added to the article.
View the archive to verify that it contains valid page information. Usually dates closer to the time the link was placed in the Wikipedia page, or earlier, are more likely to show valid information.
If you find a suitable archive URL, then you can add it to the citation. If the citation uses one of the common templates (e.g. {{template|cite web}}, {{template|cite news}}, {{template|Citation}}), then you can edit as follows:
* Leave the {{para|url}} unchanged, pointing to the source URL.
* Add {{para|archive-url}}, pointing to the archive URL.
* Add {{para|archive-date}}, specifying the date when the archived copy was saved. YYYY-MM-DD format is usually easiest but any format can be used.
* Add or change {{para|url-status}}. Use {{para|url-status|dead}} if the old URL does not work. Use {{para|url-status|unfit}} or {{para|url-status|usurped}} if the old URL has been usurped for the purposes of spam, advertising, or is otherwise unsuitable. Use {{para|url-status|live}} if {{para|url}} still works and still gives the correct information, but you want to preemptively add an {{para|archive-url}}.
* Leave the {{para|access-date}} unchanged, referring to the date when a previous editor last accessed the {{para|url}}. Some editors believe {{para|access-date}} should be removed once a working {{para|archive-url}} is established since the {{para|url}} is no longer available, maintaining an {{para|access-date}} is redundant clutter.
==Mitigating a dead link==
{{shortcut|WP:MDLI}}
At times, all attempts to repair the link will be unsuccessful. In that event, consider finding an alternate source so that the loss of the original does not harm the verifiability of the article. Alternate sources about broad topics are usually easily located. A simple search engine query might locate an appropriate alternative, but be extremely careful to avoid citing [[Wikipedia:Mirrors and forks|mirrors and forks of Wikipedia]] itself, which would violate [[Wikipedia:Verifiability]].
Sometimes, finding an appropriate source is not possible, or would require more extensive research techniques, such as a visit to a library or the use of a subscription-based database. If that is the case, consider consulting with Wikipedia editors at [[Wikipedia:WikiProject Resource Exchange]], the [[Wikipedia:Village pump]], or [[Wikipedia:Help desk]]. Also, consider contacting experts or other interested editors at a relevant [[Wikipedia:WikiProject Council/Directory|WikiProject]].
Sometimes a link is dead because the website moved the URL e.g. http://example.com moved to http://example.co.uk . If you discover an URL change like this please submit a request at [[WP:BOTREQ]] for a url move. A bot will make the change.
==Keeping dead links==
{{shortcut|WP:KDL}}
A dead, unarchived source URL may still be useful. Such a link indicates that information was (probably) verifiable in the past, and the link might provide another user with greater resources or expertise with enough information to find the reference. It could also return from the dead. With a dead link, it is possible to determine if it has been cited elsewhere, or to contact the person originally responsible for the source. For example, one could contact the Yale Computer Science department if http://www.cs.yale.edu/~EliYale/Defense-in-Depth-PhD-thesis.pdf{{dead link}} were dead. Place {{tlg|dead link|2=date={{CURRENTMONTHNAME}} {{CURRENTYEAR}}}} after the dead citation, immediately before the <code></ref></code> tag if applicable, leaving the original link intact.
Placing {{tl|dead link}} auto-categorizes the article into [[:Category:Articles with dead external links|Articles with dead external links]] project category, and into specific monthly date range category based on {{para|date}} parameter. '''Do not delete''' a citation just because it has been tagged with {{tl|dead link}} for a long time.
==Link rot on non-Wikimedia sites==
{{shortcut|WP:EXTERNALROT}}
Non-Wikimedia sites are also susceptible to link rot. Following a [[Wikipedia:Moving a page|page move]] or [[Wikipedia:Deletion process|page deletion]], links to Wikipedia pages from other websites may break. In most page moves, a [[Wikipedia:Redirect|redirect]] will remain at the old page—this won't cause a problem. But if a page is completely deleted or [[Wikipedia:Moving a page#Usurping a page title|usurped]] (i.e. replaced with other content) then link rot will have been caused on any external websites that link to it.
Replacement of page content with a [[Wikipedia:Disambiguation|disambiguation page]] may still cause link rot, but is less harmful because a disambiguation page is essentially a type of [[Wikipedia:Soft redirect|soft redirect]] that will lead the reader to the required content. If a page is usurped with content for another subject that shares its name, a [[Wikipedia:Hatnote|hatnote]] may be placed at the top that directs readers to the original content on its new page—this again is a type of soft redirect, but less obvious. In these cases, readers arriving from an external rotten link should be able to find what they're looking for, but the situation is best avoided as they would have to get there via an additional page, potentially giving a poor impression of both Wikipedia and the linking website.
Because the Wikipedia software does not store [[HTTP referer|<code>Referer</code> information]], it will be impossible to tell how many external web pages will be affected by a move or deletion, but the risk of link rot will probably be greatest on older and higher profile pages. In truth, there is not a lot that can be done; maintenance of non-Wikimedia websites is not within the scope of being a Wikimedian, nor in most cases within our capability (although if they ''can'' be fixed, it would be helpful to do so). However, it may be good practice to think about the potential impact on other sites when deleting or moving Wikipedia pages, especially if no redirect or hatnote will remain. If a move or deletion is expected to cause significant damage, then this might be a factor to consider in [[WP:RM]], [[WP:AFD]] and [[WP:RFD]] discussions, although other factors may carry more weight.
== See also ==
===Essays===
* [[Wikipedia:Build content to endure]]
* [[Wikipedia:Offline sources]]
===Tools and how-to guides===
* [[Wikipedia:Link rot/URL change requests]] – request help to change many URLs, or mark them dead
* [[Help:Using the Wayback Machine]] – how-to guide
* [[Wikipedia:Using WebCite]] – how-to guide (note: as of June 2019 WebCite no longer accepts new archive requests)
* [[Wikipedia:Using Archive.is]] – how-to guide
* [[Special:LinkSearch]] – to find all the pages that contain a particular URL
* [[Wikipedia:Citing sources/Further considerations#Pre-emptive archiving]] – brief guide on how to use various archiving services
* [[Wikipedia:Citing sources#Preventing and repairing dead links]]
* [[Wikipedia:External links#Longevity of links]] – prescribes removal of dead URLs from the "External links" section
* [[:Category:Articles with bare URLs for citations]] – the backlog of articles containing bare URLs at risk of link rot, sub-categorised by month
* [[:Category:Articles with dead external links]] – the backlog of articles containing dead links, sub-categorised by month
=== Bots ===
* [[User:InternetArchiveBot|InternetArchiveBot]] (IABot) – automatically fixes dead links whenever possible, and tags them when it isn't
* [[WP:WAYBACKMEDIC|WaybackMedic]]-automatically fixes dead links that are difficult to determine, other general fixes
* [[User:Legobot]] – can mass tag links with {{tlx|dead link}}. Requests can be made at [[User talk:Legoktm]].
<!-- * [[WP:STiki/Dead links]] – page reporting NEWLY added dead links, a component of the [[WP:STiki|STiki project]] -->
<!-- * [[User:MerlLinkBot]] – purpose is to change links in articles which are outdated and can be successfully replaced by a new one. Submit requests for link updates to the bot's [[User talk:MerlLinkBot|talk page]]. -->
<!-- * [[User:Dispenser/Reflinks]]-can automatically or semi-automatically add information to references using data present in the web page. -->
<!-- * [[User:RileyBot]] – approved to update, migrate and replace broken links with new functioning links. Submit requests for link updates at [[User:RileyBot/Requests]]. -->
<!-- * [[User:WebCiteBOT]] – (inactive since 2009) purpose is to combat link rot by automatically [[WebCite|WebCiting]] newly added URLs -->
<!-- * [[User:DeadLinkBOT]] – (inactive since 2009) purpose is to update dead links caused by link rot. Submit any updatable links found (old + new locations) to the bot's [[User talk:DeadLinkBOT|talk page]]. After human verification, the bot automatically updates affected articles. -->
=={{Anchor|Tools}} External links==
* official Wayback add-on for [https://addons.mozilla.org/en-US/firefox/addon/wayback-machine_new/ Firefox] and [https://chrome.google.com/webstore/detail/wayback-machine/fpnmgdkabkmnadcjpehmlllkndpkmiak Chrome]<ref group="note">{{cite web |title=Save Pages in the Wayback Machine |url=https://help.archive.org/hc/en-us/articles/360001513491-Save-Pages-in-the-Wayback-Machine |website=[[Internet Archive]] Help Center |date=2018-08-24}}</ref>
* [https://addons.mozilla.org/en-US/firefox/addon/resurrect-pages/ Resurrect Pages], a third-party add-on tool provides links to seven cache/archive websites upon coming across a dead link. (Firefox)
* [https://web.archive.org/web/20181118031737/https://addons.opera.com/en/extensions/details/webcache/?display=en Webcache], add-on for Opera. (discontinued; newer similar add-ons available)
* [[mw:Manual:Pywikipediabot/weblinkchecker.py|weblinkchecker.py]]—script from the [[mw:Manual:Pywikipediabot/Basic use|Python Wikipedia Bot]] collection which finds broken external links.
<!-- *[https://addons.mozilla.org/en-us/firefox/addon/404-error/ 404-Error?]—add-on for Firefox, automatically brings you to the archive.org version upon coming across a dead link.-->
<!-- *[http://antelle.net/safari/ PageHistory]—addon for Safari. -->
<!-- *[https://chrome.google.com/webstore/detail/web-cache/coblegoildgpecccijneplifmeghcgip Web Cache]—add-on for Chrome. -->
<!-- *[[tools:~dispenser/view/Checklinks|tools:Checklinks]]—an external link checker [[tools:~dispenser/view/Main Page|tool]] for Wikimedia Foundation projects, which lists dead links and allows recovery using archiving services.-->
<!-- *[http://undeadlinks.org/ UndeadLinks.org]—allows you to search for a broken link's new address.{{dead link|date=August 2017}} -->
===Notes===
{{reflist|group=note}}
{{Wikipedia essays|building}}
[[Category:Wikipedia maintenance|{{PAGENAME}}]]
[[Category:Wikipedia essays about building the encyclopedia]]
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