and
<meta name=viewport content="width=device-width,initial-scale=1,shrink-to-fit=no"><link rel=stylesheet href=../../css/main.css><link href="https://fonts.googleapis.com/css?family=Quicksand&display=swap" rel=stylesheet><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js></script><script>window.jQuery||document.write('<script src="../../js/vendors/jquery-3.3.1.min.js"><\/script>')</script><script>document.write('<script src="//pagea'+'d2.googles'+'yndication.com/pagea'+'d/js/a'+'dsby'+'google.js"><\/script>')</script><script>var superSpecialObject={};superSpecialObject['google_a'+'d_client']='ca-p'+'ub-4469282388984999';superSpecialObject['enable_page_level_a'+'ds']=true;(window['a'+'dsbygoogle']=window['a'+'dsbygoogle']||[]).push(superSpecialObject);</script><header class="page-header js-page-header"><a class=page-header-logo-container href=https://geek-questions.imtqy.com/index.html></a><div class=page-header-text>All geek questions in one place</div></header><section class="page js-page"><div itemscope itemtype=http://schema.org/QAPage class=page><div class=main-col itemprop=mainEntity itemscope itemtype=http://schema.org/Question><div class=question-header><h1 itemprop=name>HTML attribute with / without quotes</h1></div><div class=question><div class=question-row><div class=question-text><div class=description itemprop=text><p>Is there a difference between<pre class=prettyprint-override><code class="hljs xml"><span class=hljs-tag><<span class=hljs-name>iframe</span> <span class=hljs-attr>src</span>=<span class=hljs-string>"www.example.com"</span> <span class=hljs-attr>width</span>=<span class=hljs-string>100%</span>></span><span class=hljs-tag></<span class=hljs-name>iframe</span>></span></code> </pre><p>and<pre class=prettyprint-override> <code class="hljs xml"><span class=hljs-tag><<span class=hljs-name>iframe</span> <span class=hljs-attr>src</span>=<span class=hljs-string>"www.example.com"</span> <span class=hljs-attr>width</span>=<span class=hljs-string>"100%"</span>></span><span class=hljs-tag></<span class=hljs-name>iframe</span>></span></code> </pre><p>I tried both, and both seem to work, but I ask, just in case, that I need to be careful (for example, units other than%, etc.).</div><div class="favorite hidden"><i class="far fa-star"></i></div><div class=votes-question><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+12</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=tags><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" class=tag title="show questions tagged with 'html'" rel=tag>html</a> <a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" class=tag title="show questions tagged 'quotes'" rel=tag>quotes</a></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>John</a></span></span> <time title="2012-10-24 19:53" itemprop=dateCreated datetime=2012-10-24T19:53:57+0000>Oct 24 '12 at 19:53</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><ins style=height:90px;display:block data-zxname=zx-adnet data-zxadslot=ZX-QRST data-zxw=0 data-zxh=90 data-zxid=2 data-overlay=false></ins><div class=answers id=answers_hash><div class=answers-header><span class=pull-left><span itemprop=answerCount>7</span> answers</span><div class=clearfix></div></div><div class="answer-pager hidden"></div><div class="answer accepted" id=4452668_hash itemscope itemtype=http://schema.org/Answer itemprop=acceptedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>It's all about the true validity of HTML markup. This is what the W3C (WWW Consortium) is for. Many things can work in HTML, but they need to be checked to be more carefully recognized by the web browser. You can even omit the <code><html></code> and <code></html></code> tags at the beginning and at the end, but this is not recommended at all, no one does this and is considered "bad code."<p>Therefore, it is more advisable to put them in quotation marks.</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class=vote-count itemprop=upvoteCount>0</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>Davit</a></span></span> <time title="2012-10-24 19:56" itemprop=dateCreated datetime=2012-10-24T19:56:08+0000>Oct 24 '12 at 19:56</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><ins style=height:90px;display:block;margin-top:15px data-zxname=zx-adnet data-zxadslot=ZX-QRST data-zxw=0 data-zxh=90 data-zxid=3 data-overlay=false></ins><div class="answer rltd" id=4452671_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>There is no practical difference except<ul><li>if you are checking your page, quotation marks may or may not be necessary to avoid error messages, depending on the type of doctype used<li>if you serve a page with an XML content type for browsers (rarely and rarely useful), then you need quotes - otherwise the page does not appear at all, just an error message<li>If the page is otherwise processed using XML tools, quotation marks are required.</ul><p>Otherwise, quotation marks are really needed only if the attribute value contains a space, line break, quotation mark Ascii ("), apostrophe Ascii ('), serious accent (`), equal sign (=), less sign (<) or more than a character (>). Thus, <code>style = width:20em</code> will work (although it can be considered somewhat obscure), while <code>style = width: 20em</code> will not - because of the space, you need to write <code>style = "width: 20em"</code> .<p>Many people always write quotes around all attribute values, for simplicity. Others think that quotation marks make the code a little dirty, so they omit them whenever possible.<p>Whatever it is, <code>src="www.example.com"</code> means a relative URL link, not what people expect. You probably meant <code>src="http://www.example.com"</code> .</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+13</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>Jukka K. Korpela</a></span></span> <time title="2012-10-24 21:49" itemprop=dateCreated datetime=2012-10-24T21:49:25+0000>Oct 24 '12 at 21:49</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class="answer bt" id=4452670_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>According to the <strong><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel="nofollow noreferrer" src>W3C,</a></strong> there are four types of attribute syntax:<ol><li>empty attribute syntax<li>Syntax of attribute value without quotes<li>single-quote attribute value syntax<li>double-quoted attribute value syntax</ol><p>This is true for HTML5, however when referenced to & lt; HTML5 <strong><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel="nofollow noreferrer" src>W3C</a></strong> says quotation marks (single or double) are required depending on the type of document used (e.g. strict, transitional, etc.).</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+6</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>j08691</a></span></span> <time title="2012-10-24 20:01" itemprop=dateCreated datetime=2012-10-24T20:01:45+0000>Oct 24 '12 at 20:01</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class=answer id=4452672_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>This is from Google - best practices - "Minimize payload size" <a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel="nofollow noreferrer" src>https://developers.google.com/speed/docs/best-practices/payload</a> (my emphasis)<p>To keep your content compressed well, follow these steps: ... Use consistent quotes for the attributes of HTML tags, i.e. always a single quote, always a double quote, <strong>or no quotation at all</strong> , if possible.</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+3</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>tomo7</a></span></span> <time title="2014-03-06 13:08" itemprop=dateCreated datetime=2014-03-06T13:08:37+0000>Mar 6 '14 at 13:08</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class=answer id=4452667_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>No, both are the same ..<p>In HTML 5, quotation marks around attributes are simply <strong>optional.</strong> (if there are no spaces or special characters in the value)<p>But I think it's better to quote them.</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+1</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>Sushanth -</a></span></span> <time title="2012-10-24 19:55" itemprop=dateCreated datetime=2012-10-24T19:55:55+0000>Oct 24 '12 at 19:55</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class=answer id=27594774_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><blockquote><h1>The syntax of a value without quotes</h1><p>The name of the attribute, followed by zero or more spaces, followed by one character U + 003D EQUALS SIGN, followed by zero or more spaces, followed by the value of the attribute, which, in addition to the requirements given above for attribute values, is not must contain letter spaces, any characters U + 0022 QUOTATION MARK ("), characters U + 0027 APOSTROPHE ('), characters U + 003D EQUALS SIGN (=), characters U + 003C LESS-THAN SIGN (& lt;), U + 003E BIG CHARGE characters (>) or U + 0060 GRAVE ACCENT characters ('), and should not be an empty string.<p><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel="nofollow noreferrer" src>- W3 HTML5 Specification - sec 8.1.2.3.</a> <a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel="nofollow noreferrer" src>Attributes</a></blockquote></div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count greenc" itemprop=upvoteCount>+1</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>georgeawg</a></span></span> <time title="2018-08-08 17:22" itemprop=dateCreated datetime=2018-08-08T17:22:31+0000>Aug 08 '18 at 17:22</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class="answer last" id=4452669_hash itemscope itemtype=http://schema.org/Answer itemprop=suggestedAnswer><div class=answer-row><div class=answer-text><div class=desc itemprop=text><p>There is a big difference. Most browsers will see the absence of quotes and automatically insert them. If you looked at the element, you would see it. Always put quotes around values for non-smart browsers</div><div class=votes-answer><i class="glyphicon glyphicon-arrow-ups"></i><div class="vote-count redc" itemprop=upvoteCount>-1</div><i class="glyphicon glyphicon-arrow-down"></i></div><div class=clearfix></div><div class=action-time><span itemprop=author itemscope itemtype=http://schema.org/Person><span itemprop=name><a href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" rel=noopener target=_blank>Zak</a></span></span> <time title="2012-10-24 19:56" itemprop=dateCreated datetime=2012-10-24T19:56:12+0000>Oct 24 '12 at 19:56</time></div><a class=aa-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" target=_blank rel=noopener>source</a> <a itemprop=url class=s-link href="https://translate.googleusercontent.com/translate_c?depth=1&rurl=translate.google.com&sl=ru&sp=nmt4&tl=en&u=" title=share>share</a><div class=clearfix></div></div></div></div><div class="answer-pager hidden"></div></div></div></div><p>Source: <a rel=nofollow href=https://habr.com/ru/post/1441897/>https://habr.com/ru/post/1441897/</a><section class="more-articles-navigation-panel js-more-articles-navigation-panel"><h4>More articles:</h4><nav class="list-of-articles-container js-list-of-articles-container"><ul class="list-of-pages js-list-of-pages"><li><a href=../1441892/index.html>Parsing YYYY-MM-DD dates strictly on Linux - linux</a><li><a href=../1441893/index.html>Delphi - Hide console window - delphi</a><li><a href=../1441894/index.html>Creating a new table from two existing tables with the possibility of each combination - sql</a><li><a href=../1441895/index.html>How to hide the console window? - delphi</a><li><a href=../1441896/index.html>C # .net winforms DataGridView footer - c #</a><li><a href=../1441898/index.html>Rapid device testing << in C ++ - c ++</a><li><a href=../1441899/index.html>How to WebBrowser.Navigate () from BackgroundWorker? - c #</a><li><a href=../1441900/index.html>Building a custom expression tree in Spirit: Qi (without Utree or Boost :: Variant) - c ++</a><li><a href=../1441901/index.html>is there any advantage to using int instead of float without decimal numbers? - floating-point</a><li><a href=../1441902/index.html>How to add qi :: characters in the <iterator, double ()>grammar? - c ++</a></ul></nav></section><br><a href=../../allArticles.html><strong>All Articles</strong></a> <script src=../../js/main.js></script><script>(function(d,w,c){(w[c]=w[c]||[]).push(function(){try{w.yaCounter62683636=new Ya.Metrika({id:62683636,clickmap:true,trackLinks:true,accurateTrackBounce:true,webvisor:true});}catch(e){}});var n=d.getElementsByTagName("script")[0],s=d.createElement("script"),f=function(){n.parentNode.insertBefore(s,n);};s.type="text/javascript";s.async=true;s.src="https://mc.yandex.ru/metrika/watch.js";if(w.opera=="[object Opera]"){d.addEventListener("DOMContentLoaded",f,false);}else{f();}})(document,window,"yandex_metrika_callbacks");</script><noscript><div><img src=https://mc.yandex.ru/watch/62683636 style=position:absolute;left:-9999px alt></div></noscript><script>window.ga=function(){ga.q.push(arguments)};ga.q=[];ga.l=+new Date;ga('create','UA-166339405-1','auto');ga('send','pageview')</script><script src=https://www.google-analytics.com/analytics.js async defer></script></section><footer class=page-footer><div class="page-footer-legal-info-container page-footer-element"><p>Geek Questions | <span class="page-footer-legal-info-year js-page-footer-legal-info-year">2019</span></div><div class="page-footer-counters-container page-footer-element"><a class=page-footer-counter-clustrmap href=# title="Visit tracker"><img src="https://clustrmaps.com/map_v2.png?cl=698e5a&w=271&t=t&d=x9KFE5t3Mv44EqtuX_BNXcB69A0sIUZAkKxnezcia0Y&co=3a3a3a&ct=ffffff"></a></div></footer>