Editing Blink element

{{short description|HTML element causing flashing text}}
{{HTML}}
The '''blink element''' is a non-standard [[HTML element]] that indicates to a [[user agent]] (generally a [[web browser]]) that the page author intends the content of the element to blink (that is, alternate between being visible and invisible).<ref name=":0">{{Cite web |title=&lt;blink&gt;: The Blinking Text element |url=https://developer.mozilla.org/en-US/docs/Web/HTML/Element/blink |url-status=dead |archive-url=https://web.archive.org/web/20230510064635/https://developer.mozilla.org/en-US/docs/Web/HTML/Element/blink |archive-date=2023-05-10 |access-date=2017-09-11 |website=[[MDN Web Docs]] |publisher=[[Mozilla]] |language=en-US}}</ref> The element was introduced in [[Netscape Navigator]]<ref name=":1">{{Cite web |last=Montulli |first=Lou |author-link=Lou Montulli |title=The Origins of the &lt;Blink&gt; Tag |url=http://www.montulli.org/theoriginofthe%3Cblink%3Etag |url-status=dead |archive-url=https://web.archive.org/web/20220331020029/http://www.montulli.org/theoriginofthe%3Cblink%3Etag |archive-date=2022-03-31 |access-date=2017-09-11 |website=www.montulli.org}}</ref> but is no longer supported and often ignored by modern Web browsers; some, such as [[Internet Explorer]], never supported the element at all.<ref name=":0" />

Despite its initial popularity among [[personal homepage|home users]] in the 1990s, it fell out of favor due to its overuse and the difficulty it presents in reading.<ref>{{Cite news |last=Eaton |first=Kit |date=2013-08-07 |title=Saying Goodbye To The HTML Blink Tag |language=en-US |work=[[Fast Company]] |url=https://www.fastcompany.com/3015408/saying-goodbye-to-the-html-tag |url-status=live |access-date=2017-09-11 |archive-url=https://web.archive.org/web/20220519144714/https://www.fastcompany.com/3015408/saying-goodbye-to-the-html-tag |archive-date=2022-05-19}}</ref> [[Lou Montulli]], often credited as the inventor of the blink element, claims he only suggested the idea, without writing any actual code.<ref name=":1" />
{{quote|text=
... At some point in the evening I mentioned that it was sad that [[Lynx (web browser)|Lynx]] was not going to be able to display many of the HTML extensions that we were proposing, I also pointed out that the only text style that Lynx could exploit given its environment was blinking text. We had a pretty good laugh at the thought of blinking text, and talked about blinking this and that and how absurd the whole thing would be.&nbsp;... Saturday morning rolled around and I headed into the office only to find what else but, blinking text. It was on the screen blinking in all its glory, and in the browser. How could this be, you might ask? It turns out that one of the engineers liked my idea so much that he left the bar sometime past midnight, returned to the office and implemented the blink tag overnight. He was still there in the morning and quite proud of it.<ref name=":1" />}}

== Usage ==
{{Quote box
| width = 250px
| class = noprint
| quote = {{blink|'''Hello, World!'''}}
| qstyle= font-size: 150%; color: #FF0000;
| source = Example of blinking text (accomplished via CSS; the &lt;blink&gt; tag itself is deprecated and no longer works in most browsers)
}}
The blink element is non-standard, and as such there is no authoritative specification of its syntax or semantics. While [[Bert Bos]] of the [[World Wide Web Consortium]] has produced a [[Document Type Definition]] that includes syntax for the blink element (defining it as a ''phrase element'' on a par with elements for [[emphasis (typography)|emphasis]] and [[citations]]), the comments in the DTD explain that it is intended as a joke.<ref>{{cite web |last=Bos |first=Bert |author-link=Bert Bos |date=1999-11-10 |title=HTML40, but with BLINK added |url=http://www.w3.org/Style/HTML40-plus-blink.dtd |url-status=live |archive-url=https://web.archive.org/web/20230122040932/https://www.w3.org/Style/HTML40-plus-blink.dtd |archive-date=2023-01-22 |access-date=12 December 2006 |publisher=[[World Wide Web Consortium]] |quote=This is basically just HTML40, but with BLINK added...The BLINK is merely added as a joke.}}</ref>

Syntax of the blink element type is identical to such standard [[HTML]] inline elements as span. For example: {{code|lang=html|code=<blink>This text could blink</blink>}}. The rate of blinking is browser-specific, and the tag contains no parameters or means to adjust the rate of blinking. In versions of [[Mozilla Firefox]] that support the tag, the text alternates between being visible for three quarters of a second and being invisible for one quarter of a second.<ref name="mozilla-corporation">{{cite web |date=2009-07-13 |title=VPAT for Firefox 3.0 and 3.5 |url=http://www.mozilla.com/en-US/firefox/vpat.html |url-status=dead |archive-url=https://web.archive.org/web/20080517030113/http://www.mozilla.com/en-US/firefox/vpat.html |archive-date=17 May 2008 |access-date=23 October 2009 |publisher=[[Mozilla]] |quote="When pages use the HTML &lt;blink&gt; tag, Firefox uses a 1 Hz duty cycle with the text visible for 3/4 of each cycle." }}</ref>

The blink element type was first invented for [[Netscape Navigator]] and was supported in its descendants, such as [[Mozilla Firefox]] (except for the ''[[Netscape 6]]'' and early [[Mozilla Application Suite|Mozilla suite]] browsers—it is thus also absent from [[SeaMonkey]], which descends from Mozilla suite); it was removed from [[Firefox]] in version 23.<ref name="firefox23">{{cite web |date=6 August 2013 |title=Firefox 23 Release Notes |url=https://www.mozilla.org/en-US/firefox/23.0/releasenotes/ |url-status=live |archive-url=https://web.archive.org/web/20230707093918/https://www.mozilla.org/en-US/firefox/23.0/releasenotes/ |archive-date=2023-07-07 |access-date=8 August 2013 |publisher=[[Mozilla]] |quote=...Dropped blink effect from text-decoration: blink; and completely removed &lt;blink&gt; element...}}</ref><ref name=":0" /> [[Microsoft]]'s [[Internet Explorer]] and [[WebKit]] (the browser engine behind [[Apple Inc.|Apple]]'s [[Safari (web browser)|Safari]] and [[Google Chrome]]) never supported it, even in its CSS incarnation. It was also supported by the [[Opera (web browser)|Opera Internet Browser]], but support ended in version 15 when that browser switched to a WebKit-based engine. [[Vivaldi (web browser)|Vivaldi]], despite its roots as a spiritual successor to the [[Presto (browser engine)|Presto]]-based Opera, also does not support a functional blink tag.

[[Netscape (web browser)|Netscape]] only agreed to remove the blink tag from their browser if [[Microsoft]] agreed to get rid of the [[Marquee element|marquee]] tag in theirs during an HTML ERB meeting in February 1996.<ref>{{Cite web |last1=Raggett |first1=Dave |author-link=Dave Raggett |last2=Lam |first2=Jenny |last3=Alexander |first3=Ian |last4=Kmiec |first4=Michael |date=1998 |title=Chapter 2 - A history of HTML |url=https://www.w3.org/People/Raggett/book4/ch02.html |url-status=live |archive-url=https://web.archive.org/web/20230713020927/https://www.w3.org/People/Raggett/book4/ch02.html |archive-date=13 July 2023 |access-date=2023-07-24 |publisher=[[World Wide Web Consortium]] |quote=The BLINK tag was ousted in an HTML ERB meeting. Netscape would only abolish it if Microsoft agreed to get rid of MARQUEE; the deal was struck and both tags disappeared.}}</ref>

Some software supports the blink element as an [[Easter Egg (media)|easter egg]]. [[Google Search]] blinks parts of the page when one searches for "blink html".<ref>{{Cite news |last1=Shankland |first1=Stephen |last2=King |first2=Mary |date=16 April 2022 |title=20 Hidden Google Search Easter Eggs to Hunt For |work=[[CNET]] |url=https://www.cnet.com/tech/services-and-software/20-hidden-google-search-easter-eggs-to-hunt-for/ |url-status=live |access-date=24 July 2023 |archive-url=https://web.archive.org/web/20230527042407/https://www.cnet.com/tech/services-and-software/20-hidden-google-search-easter-eggs-to-hunt-for/ |archive-date=27 May 2023 |quote=Type blink HTML into the search box, and you'll get a list of search results where the words "blink" and "HTML" are blinking.}}</ref> [[Android (operating system)|Android]]'s user interface framework supports the blink tag, labeling it as <code>TAG_1995</code> in its source code.<ref>{{Cite web |title=core/java/android/view/LayoutInflater.java - platform/frameworks/base |url=https://android.googlesource.com/platform/frameworks/base/+/49e7040b926280b8decbeee87b532eb6b55d7e58/core/java/android/view/LayoutInflater.java#146 |access-date=2019-09-20 |website=Google Git |publisher=[[Android Open Source Project]], [[Google]] |quote=146 private static final String TAG_1995 = "blink";}}</ref>

== Implementation ==
The ''blink'' value of the [[Cascading Style Sheets|CSS]] ''text-decoration'' property allows authors to suggest that text should blink without using proprietary tags, but the ''CSS 2.1 Specification'' states that "conforming user agents may simply not blink the text" in order to comply with the ''User Agent Accessibility Guidelines''.<ref>{{cite web |title=Underlining, overlining, striking, and blinking: the 'text-decoration' property |url=https://www.w3.org/TR/2011/REC-CSS2-20110607/text.html#lining-striking-props |url-status=live |archive-url=https://web.archive.org/web/20230511002456/https://www.w3.org/TR/2011/REC-CSS2-20110607/text.html |archive-date=2023-05-11 |access-date=2023-07-24 |website=Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification |publisher=[[CSS Working Group]], [[World Wide Web Consortium]]}}</ref>
<!--
Example:

-->
<syntaxhighlight lang="html" line="1">
<span style="text-decoration: blink;">Down to the porshrop, down to the streep</span>
</syntaxhighlight>
This produces the following on the page — it is unlikely to actually blink due to modern browsers lacking support for the tag:
:<span style="text-decoration: blink;">Down to the porshrop, down to the streep</span>
The blink element may also be implemented using [[CSS animations]].
<syntaxhighlight lang="css" line="1">
@keyframes blink {
	0% { opacity:1 } 75% { opacity:1 } 76% { opacity:0 } 100% { opacity:0 }
}

blink, .blink-css {
	animation:blink 0.75s ease-in infinite alternate!important;
}
</syntaxhighlight>
When elements are then given the tag <code>blink</code> or class <code>blink-css</code>, such as:
<syntaxhighlight lang="html" line="1">
<span class="blink-css">Down to the porshrop, to the porshrop family treep</span>
</syntaxhighlight>
This produces the following:<!--
The following templatestyles imports [[Template:Blink/styles.css]] which is just the exact same thing whose source code is given above.
--><templatestyles src="Blink/styles.css" />
:<span class="blink-css">Down to the porshrop, to the porshrop family treep</span>
Similar effects can also be achieved through the use of [[JavaScript]].
<syntaxhighlight lang="html" line="1">
<script type="text/javascript">
  (function() {
    var blinks = document.getElementsByTagName('blink');
    var visibility = 'hidden';
    window.setInterval(function() {
      for (var i = blinks.length - 1; i >= 0; i--) {
        blinks[i].style.visibility = visibility;
      }
      visibility = (visibility === 'visible') ? 'hidden' : 'visible';
    }, 250);
  })();
</script>
<blink>Text to blink here</blink>
</syntaxhighlight>

Or alternatively, the ''blink'' functionality can be implemented with the help of [[jQuery]].
<syntaxhighlight lang="html" line="1">
<script type="text/javascript">
    setInterval(function(){
      $('blink').each(function() {
        $(this).toggle();
      });
    }, 250);
</script>
<blink>Text to blink here</blink>
</syntaxhighlight>

== Usability and accessibility ==
Even before the implementing of the blink tag in HTML, the [[Apple IIe]] had a flashing text mode, alternating between standard white-on-black and inverse black-on-white text. A 1982 [[Apple Computer]] manual for developers advised against using this feature except for emergencies, warning that "[f]lashing [text] should only be used to indicate imminent destruction of data or the program".<ref name="apple1982">{{cite book |last1=Meyers |first1=Joe |url=https://archive.org/download/apple-iie-design-guidelines/Apple%20IIe%20Design%20Guidelines.pdf |title=Apple IIe Design Guidelines |last2=Tognazzini |first2=Bruce |publisher=[[Apple Inc.]] |year=1982 |location=Cupertino, California |page=38 |language=en-US |chapter=Displays |quote=Flashing [text] should only be used to indicate imminent destruction of data or the program. |author-link2=Bruce Tognazzini |access-date=24 July 2023 |via=[[Internet Archive]]}}</ref> 

The blink element has been consistently criticized by [[usability]] and [[accessibility]] experts. In 1996 [[Jakob Nielsen (usability consultant)|Jakob Nielsen]] described the element as "simply evil" in his ''Alertbox'' column "Original Top Ten Mistakes in Web Design".<ref>{{cite web |last=Nielsen |first=Jakob |author-link=Jakob Nielsen (usability consultant) |date=April 30, 1996 |title=Original Top Ten Mistakes in Web Design |url=https://www.nngroup.com/articles/original-top-ten-mistakes-in-web-design/ |url-status=live |archive-url=https://web.archive.org/web/20230705043841/https://www.nngroup.com/articles/original-top-ten-mistakes-in-web-design/ |archive-date=5 July 2023 |access-date=24 July 2023 |website=[[Nielsen Norman Group]] |publisher= |quote=Of course, <BLINK> is simply evil. Enough said.}}</ref>
The World Wide Web Consortium's ''[[Web Content Accessibility Guidelines]] (WCAG) 1.0'' state that content authors should avoid causing the screen to flicker or blink, noting that such effects can cause problems for people with [[cognitive disability|cognitive disabilities]] or [[photosensitive epilepsy]].<ref>{{cite web|url=http://www.w3.org/TR/WCAG10/|title=Web Content Accessibility Guidelines 1.0|first1=Wendy|last1=Chisholm|first2=Gregg|last2=Vanderheiden|first3=Ian|last3=Jacobs|publisher=[[World Wide Web Consortium]]|date=5 May 1999|access-date=20 July 2010}}</ref>

The [[United States Access Board]] states that pages should "not use flashing or blinking text, objects, or other elements having a flash or blink frequency greater than 2 [[Hertz|Hz]] and lower than 55Hz."<ref>{{Cite web |date=18 January 2017 |title=Revised 508 Standards and 255 Guidelines |url=https://www.access-board.gov/ict/#d21 |url-status=live |archive-url=https://web.archive.org/web/20230708091554/https://www.access-board.gov/ict/ |archive-date=8 July 2023 |access-date=2023-07-24 |website= |publisher=[[United States Access Board]] |quote=Software shall not use flashing or blinking text, objects, or other elements having a flash or blink frequency greater than 2 Hz and lower than 55 Hz.}}</ref>

The [[Germany|German]] Federal Government's ''Barrierefreie Informationstechnik-Verordnung'' (''Accessible Information Technology Ordinance'') also states that flickering or blinking content should be avoided.<ref>{{cite web|url=http://www.gesetze-im-internet.de/bitv_2_0/BJNR184300011.html |title=BITV&nbsp;— Einzelnorm |publisher=gesetze-im-internet.de |date=12 September 2011 |access-date=3 March 2014}}</ref>

To comply with the ''User Agent Accessibility Guidelines'' a user agent must either "[a]llow configuration to render animated or blinking text content as motionless, unblinking text" or never blink text.<ref>{{cite web |date=17 December 2002 |title=User Agent Accessibility Guidelines 1.0 |url=https://www.w3.org/TR/UAAG/guidelines.html |url-status=live |archive-url=https://web.archive.org/web/20230526201528/https://www.w3.org/TR/UAAG/guidelines.html |archive-date=26 May 2023 |access-date=23 October 2009 |publisher=[[World Wide Web Consortium]] |quote=Allow configuration to render animated or blinking text content as motionless, unblinking text.}}</ref> [[Mozilla Firefox]] satisfied this requirement by providing a hidden configuration option to disable blinking,<ref name="mozilla-corporation"/> ''browser.blink_allowed'', which could be accessed through [[About: URI scheme|about:config]]. The blinking feature has been disabled altogether since version 23.<ref name="firefox23"/>

== See also ==
* [[Marquee element]]

== References ==
{{reflist}}

== External links ==
* [https://web.archive.org/web/20140428062755/http://siteexperts.com/tips/html/ts12/page1.asp Cross Browser Blink Tag]
{{Use dmy dates|date=May 2016}}

{{DEFAULTSORT:Blink Element}}
[[Category:HTML tags]]
[[Category:Netscape]]
[[Category:Web 1.0]]