Editing Ad blocking (section)

===Browser integration===
{{As of|2015}}, many web browsers block unsolicited [[pop-up ad]]s automatically. Current versions of [[Konqueror]],<ref>{{cite web |url=https://konqueror.org/features/browser.php |title=Konqueror browser features |access-date=23 March 2019 |archive-date=10 April 2019 |archive-url=https://web.archive.org/web/20190410141201/https://konqueror.org/features/browser.php |url-status=live }}</ref> [[Microsoft Edge]],<ref>{{cite web |url=https://support.microsoft.com/en-us/help/17288 |title=Use Do Not Track in Internet Explorer 11 |access-date=23 March 2019 |archive-date=1 May 2021 |archive-url=https://web.archive.org/web/20210501023526/https://support.microsoft.com/en-us/windows/use-do-not-track-in-internet-explorer-11-ad61fa73-d533-ce96-3f64-2aa3a332e792 |url-status=live }},</ref> and [[Firefox]]<ref>{{Cite web |website=support.mozilla.org |title=Enhanced Tracking Protection in Firefox for desktop |access-date=23 January 2021 |url=https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop |archive-url=https://archive.today/20210123153639/https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop |archive-date=23 January 2021 |url-status=live }}</ref><ref>{{Cite web |title=Content blocking |archive-url=https://archive.today/20210123153755/https://support.mozilla.org/en-US/kb/content-blocking |url=https://support.mozilla.org/en-US/kb/content-blocking |archive-date=23 January 2021 |access-date=23 January 2021 |website=support.mozilla.org |url-status=live }}</ref> also include content filtering support out-of-the-box. Content filtering can be added to [[Firefox browser|Firefox]], [[Chromium browser|Chromium-based browsers]], [[Opera browser|Opera]], [[Safari browser|Safari]], and other browsers with extensions such as [[AdBlock]], [[Adblock Plus]], and [[uBlock Origin]], and a number of sources provide regularly updated filter lists. Adblock Plus is included in the freeware browser [[Maxthon]] from the [[People's Republic of China]] by default.<ref>{{cite web |url=https://adblockplus.org/blog/adblock-plus-integrated-into-maxthon-browser |title=Adblock Plus integrated into Maxthon browser |first=Job |last=Plas |date=11 February 2015 |access-date=23 March 2019 |archive-date=2 February 2019 |archive-url=https://web.archive.org/web/20190202223035/https://adblockplus.org/blog/adblock-plus-integrated-into-maxthon-browser |url-status=live }}</ref>

Another method for filtering advertisements uses [[Cascading Style Sheets]] (CSS) rules to hide specific [[HTML]] and [[XHTML]] [[HTML element|elements]]. This was once handled directly by a browser's user style sheet and custom CSS files. The CSS files employed regular expressions to describe a general advertisement profile. An example CSS selector from the once popular Floppy Moose (2003) style sheet is below.<ref>{{cite web |url=http://www.floppymoose.com/userContent.css |title=Archived copy |website=floppymoose.com |access-date=1 September 2022 |archive-url=https://web.archive.org/web/20031007231436/http://www.floppymoose.com/userContent.css |archive-date=7 October 2003 |url-status=dead}}</ref> It simply hides anything with a link containing the characters "ad."<ref>{{cite web|url=https://digiwonk.gadgethacks.com/how-to/use-ad-blockers-stop-ads-from-displaying-your-web-browser-0126987/|title=How to Use Ad Blockers to Stop Ads from Displaying in Your Web Browser |date=23 April 2011 }}</ref>

<syntaxhighlight lang="css">a:link[href*="ad."] img</syntaxhighlight>

Stylesheets are still used to block ads today. However they are almost always used by an ad-blocking extension that combines CSS with other techniques. AdBlock Plus syntax includes CSS selectors which they call "element hiding" rules.<ref>{{cite web|url=https://help.eyeo.com/en/adblockplus/how-to-write-filters#element-hiding|title=How to write filters &#124; Adblock Plus Help Center }}</ref> The newer uBlock Origin even allows "cosmetic filters" which inject custom CSS declarations.<ref>{{cite web|url=https://portswigger.net/research/ublock-i-exfiltrate-exploiting-ad-blockers-with-css|title=uBlock, I exfiltrate: Exploiting ad blockers with CSS|date=6 December 2021}}</ref> Due to changes in advertising techniques, modern ad-blockers use more specific selectors, more frequently updated selectors, and a greater quantity of selectors. For example, the Floppy Moose style sheet originally contained 40 lines of CSS. In 2022, Easylist contains thousands of CSS selectors. In contrast to the general example above, below is one of the many specific CSS selectors from Easylist (2022).<ref>{{cite web |url=https://easylist.to/easylist/easylist.txt |title=EasyList |access-date=18 September 2022 |date=18 September 2022 |last=The EasyList authors |website=EasyList.to |editor=MontzA}}</ref>

<syntaxhighlight lang="css">a[href^="https://topoffers.com/"][href*="/?pid="]</syntaxhighlight>

In January 2016, [[Brave (web browser)|Brave]], a free, ad-blocking browser for Mac, PC, Android, and iOS devices was launched. Brave users can optionally enable Brave's own ad network to earn [[Basic Attention Token]]s (BATs), a type of cryptocurrency, which can be sent as micro-payments to publishers.<ref>{{Cite web|date=2018-07-24|title=The Brave browser basics – what it does, how it differs from rivals|url=https://www.computerworld.com/article/3292619/the-brave-browser-basics-what-it-does-how-it-differs-from-rivals.html|access-date=2020-11-23|website=Computerworld|language=en|archive-url=https://archive.today/20200529204354/https://www.computerworld.com/article/3292619/the-brave-browser-basics-what-it-does-how-it-differs-from-rivals.html|archive-date=29 May 2020|last1=Keizer|first1=Gregg|url-status=live}}</ref>

At the beginning of 2018, Google confirmed that the built-in ad blocker for the [[Google Chrome|Chrome]]/[[Chromium (web browser)|Chromium]] browsers would go live on 15 February:<ref>{{cite web |url=https://www.blog.google/products/chrome/browser-web-worth-protecting/ |title=The browser for a web worth protecting |first=Rahul |last=Roy-Chowdhury |date=13 February 2018 |access-date=23 March 2019 |archive-date=6 June 2019 |archive-url=https://web.archive.org/web/20190606030419/https://blog.google/products/chrome/browser-web-worth-protecting/ |url-status=live }}</ref> this ad blocker only blocks certain ads as specified by the ''Better Ads Standard''<ref>{{cite web |url=https://blog.chromium.org/2018/02/how-chromes-ad-filtering-works.html |title=Under the hood: How Chrome's ad filtering works |date=14 February 2018 |access-date=23 March 2019 |archive-date=18 June 2019 |archive-url=https://web.archive.org/web/20190618160145/https://blog.chromium.org/2018/02/how-chromes-ad-filtering-works.html |url-status=live }}</ref> (defined by the Coalition for ''Better Ads'', in which Google itself is a board member<ref>{{cite web |url=https://www.betterads.org/members/ |title=Members |publisher=Coalition for Better Ads |access-date=23 March 2019 |archive-date=10 May 2019 |archive-url=https://web.archive.org/web/20190510191350/https://www.betterads.org/members/ |url-status=live }}</ref>). This built-in ad blocking mechanism is disputed because it could unfairly benefit Google's advertising itself.<ref>{{cite web |url=http://fortune.com/2018/02/15/google-chrome-ad-blocking-2/ |title=Why Google's Ad-Blocking in Chrome Might Prove Awkward For the Company |date=15 February 2018 |first=David |last=Meyer |access-date=23 March 2019 |archive-date=28 October 2018 |archive-url=https://web.archive.org/web/20181028101922/http://fortune.com/2018/02/15/google-chrome-ad-blocking-2/ |url-status=live }}</ref>

In 2019, both [[Apple Inc.|Apple]] and Google began to make changes to their web browsers' extension systems which encourage the use of declarative content blocking using pre-determined filters processed by the web browser, rather than filters processed at runtime by the extension. Both vendors have imposed limits on the number of entries that may be included in these lists, which have led to (especially in the case of Chrome) allegations that these changes are being made to inhibit the effectiveness of ad blockers.<ref>{{Cite web|url=https://www.zdnet.com/article/google-promises-to-play-nice-with-ad-blockers-again/|title=Google promises to play nice with ad blockers (again)|last=Cimpanu|first=Catalin|website=ZDNet|language=en|access-date=13 June 2019|archive-date=7 November 2020|archive-url=https://web.archive.org/web/20201107233236/https://www.zdnet.com/article/google-promises-to-play-nice-with-ad-blockers-again/|url-status=live}}</ref><ref>{{Cite web|url=https://www.zdnet.com/article/google-chrome-could-soon-kill-off-most-ad-blocker-extensions/|title=Google Chrome could soon kill off most ad-blocker extensions|last=Tung|first=Liam|website=ZDNet|language=en|access-date=13 June 2019|archive-date=19 December 2020|archive-url=https://web.archive.org/web/20201219125215/https://www.zdnet.com/article/google-chrome-could-soon-kill-off-most-ad-blocker-extensions/|url-status=live}}</ref><ref>{{Cite web|url=https://www.cnet.com/news/google-says-chrome-isnt-killing-ad-blockers-its-making-them-safer/|title=Google says Chrome isn't killing ad blockers|last=Mihalcik|first=Carrie|website=CNET|language=en|access-date=13 June 2019|archive-date=13 June 2019|archive-url=https://web.archive.org/web/20190613172004/https://www.cnet.com/news/google-says-chrome-isnt-killing-ad-blockers-its-making-them-safer/|url-status=live}}</ref><ref>{{Cite web|url=https://www.zdnet.com/article/apple-neutered-ad-blockers-in-safari-but-unlike-chrome-users-didnt-say-a-thing/|title=Apple neutered ad blockers in Safari, but unlike Chrome, users didn't say a thing|last=Cimpanu|first=Catalin|website=ZDNet|language=en|access-date=23 September 2019|archive-date=23 September 2019|archive-url=https://web.archive.org/web/20190923012641/https://www.zdnet.com/article/apple-neutered-ad-blockers-in-safari-but-unlike-chrome-users-didnt-say-a-thing/|url-status=live}}</ref>