{"id":130306,"date":"2021-01-12T11:00:44","date_gmt":"2021-01-12T16:00:44","guid":{"rendered":"https:\/\/ahrefs.com\/blog\/?p=130306"},"modified":"2023-05-15T06:03:46","modified_gmt":"2023-05-15T11:03:46","slug":"how-ahrefs-counts-links","status":"publish","type":"post","link":"https:\/\/ahrefs.com\/blog\/how-ahrefs-counts-links\/","title":{"rendered":"How Ahrefs Counts Links and Domains"},"content":{"rendered":"<div class=\"intro-txt\">Every backlink tool will store different links.<\/div>\n<p>When building an index of the web, companies have to make many choices around crawling, parsing, and indexing data. While there\u2019s going to be a lot of overlap between indexes, there\u2019s also going to be some differences depending on each company\u2019s decisions.<\/p>\n<p>In the name of transparency, we want to let people know more about Ahrefs\u2019 link&nbsp;index.<\/p>\n<ul>\n<li><a href=\"#link-explanation\">What is a&nbsp;link?<\/a><\/li>\n<li><a href=\"#which-links\">Which links get indexed?<\/a><\/li>\n<li><a href=\"#which-domains\">Which domains get indexed?<\/a><\/li>\n<li><a href=\"#why-we-cant-see-all-links\">Why we can\u2019t see all&nbsp;links<\/a><\/li>\n<\/ul>\n<div class=\"post-nav-link clearfix\" id=\"section1\"><a class=\"subhead-anchor\" data-tip=\"tooltip__copielink\" rel=\"#section1\"><svg width=\"19\" height=\"19\" viewBox=\"0 0 14 14\" style><g fill=\"none\" fill-rule=\"evenodd\"><path d=\"M0 0h14v14H0z\" \/><path d=\"M7.45 9.887l-1.62 1.621c-.92.92-2.418.92-3.338 0a2.364 2.364 0 0 1 0-3.339l1.62-1.62-1.273-1.272-1.62 1.62a4.161 4.161 0 1 0 5.885 5.884l1.62-1.62L7.45 9.886zM5.527 5.135L7.17 3.492c.92-.92 2.418-.92 3.339 0 .92.92.92 2.418 0 3.339L8.866 8.473l1.272 1.273 1.644-1.643A4.161 4.161 0 1 0 5.897 2.22L4.254 3.863l1.272 1.272zm-.66 3.998a.749.749 0 0 1 0-1.06l2.208-2.206a.749.749 0 1 1 1.06 1.06L5.928 9.133a.75.75 0 0 1-1.061 0z\" style \/><\/g><\/svg><\/a><div class=\"link-text\" data-anchor=\"What is a link?\" data-section=\"link-explanation\">\n<h2>What is a&nbsp;link?<\/h2>\n<\/div><\/div>\n<p><a href=\"https:\/\/ahrefs.com\/blog\/what-are-backlinks\/\">Links<\/a>&nbsp;take users from one webpage to another when clicked. There are many ways to create them, with the most common method being the classic HTML <code>&lt;a&gt;<\/code> element with an href attribute.<\/p>\n<p><code>&lt;a href=\"url\"&gt;link text&lt;\/a&gt;<\/code><\/p>\n<p>However, it\u2019s possible to create links with other elements, including:<\/p>\n<ul>\n<li>Onclick<\/li>\n<li>Button<\/li>\n<li>Ng-click<\/li>\n<li>Option\/value<\/li>\n<li>And more\u2026<\/li>\n<\/ul>\n<div class=\"post-nav-link clearfix\" id=\"section1\"><a class=\"subhead-anchor\" data-tip=\"tooltip__copielink\" rel=\"#section1\"><svg width=\"19\" height=\"19\" viewBox=\"0 0 14 14\" style><g fill=\"none\" fill-rule=\"evenodd\"><path d=\"M0 0h14v14H0z\" \/><path d=\"M7.45 9.887l-1.62 1.621c-.92.92-2.418.92-3.338 0a2.364 2.364 0 0 1 0-3.339l1.62-1.62-1.273-1.272-1.62 1.62a4.161 4.161 0 1 0 5.885 5.884l1.62-1.62L7.45 9.886zM5.527 5.135L7.17 3.492c.92-.92 2.418-.92 3.339 0 .92.92.92 2.418 0 3.339L8.866 8.473l1.272 1.273 1.644-1.643A4.161 4.161 0 1 0 5.897 2.22L4.254 3.863l1.272 1.272zm-.66 3.998a.749.749 0 0 1 0-1.06l2.208-2.206a.749.749 0 1 1 1.06 1.06L5.928 9.133a.75.75 0 0 1-1.061 0z\" style \/><\/g><\/svg><\/a><div class=\"link-text\" data-anchor=\"Which links get indexed?\" data-section=\"which-links\">\n<h2>Which links get indexed?<\/h2>\n<\/div><\/div>\n<p>In an ideal world, anything that functions as a link would be stored. Unfortunately, we don\u2019t live in an ideal world. Neither Ahrefs nor Google stores all types of links because it\u2019s not an efficient process to load each page and click every link. That\u2019s exactly what you\u2019d have to do if you want to find all of the links that work for&nbsp;users.<\/p>\n<p>Instead, crawlers typically fetch pages, possibly render them, then extract and store various types of links. All crawlers work differently, so let\u2019s talk about how we do things here at Ahrefs.<\/p>\n<h3>Links we&nbsp;store<\/h3>\n<p>Here are the types of links we store in our&nbsp;index.<\/p>\n<h4>External links<\/h4>\n<p>Links from one website to another created using the classic HTML <code>&lt;a&gt;<\/code> element with an href attribute.<\/p>\n<h4>Internal links<\/h4>\n<p>Links from one page on a website to another page on the same website. There are 22.21 trillion internal backlinks in our index. That\u2019s far more extensive than our live external link count. We\u2019re the only SEO tool where you can access this data without a custom website crawl. We use the internal link data in the <a href=\"https:\/\/help.ahrefs.com\/en\/articles\/72658-what-is-url-rating-ur\">URL Rating (UR)<\/a>&nbsp;calculation, similar to how Google would use it in their <a href=\"https:\/\/ahrefs.com\/blog\/google-pagerank\/\">PageRank<\/a>&nbsp;calculation.<\/p>\n<p>If you want to see when we first and last crawled a URL, you can check the \u201cBest by links\u201d report in <a href=\"https:\/\/ahrefs.com\/site-explorer\">Site Explorer<\/a>. There are tabs for both External and Internal Links.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1600\" height=\"1091\" class=\"wp-image-130305\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/best-by-links-report.jpg\" alt=\"best by links report\" srcset=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/best-by-links-report.jpg 1600w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/best-by-links-report-623x425.jpg 623w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/best-by-links-report-768x524.jpg 768w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/best-by-links-report-1536x1047.jpg 1536w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\"><\/p>\n<h3>Links we may&nbsp;store<\/h3>\n<p>Here are all the links we store under some circumstances.<\/p>\n<h4>Links inserted with JavaScript<\/h4>\n<p>Because Google renders all pages, they can count links that are inserted with JavaScript but aren\u2019t in the HTML code. Rendering at scale takes a lot more resources than just downloading the HTML of pages. At Ahrefs, we render around 80 million pages per day. That\u2019s why we will have some of these links inserted by JavaScript, but not all of them. We\u2019re currently the only SEO tool that renders during our regular crawling of the web, so we have some link data that other tools don\u2019t&nbsp;have.<\/p>\n<p>However, we only count links inserted with JavaScript if they are in the format of an HTML <code>&lt;a&gt;<\/code> element with an href attribute. You\u2019ll see these links tagged in the backlinks report as \u201cJS,\u201d like&nbsp;this:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"150\" class=\"wp-image-130301\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/js-link.png\" alt=\"js link\"><\/p>\n<h4>Links from pages with URL parameters<\/h4>\n<p><a href=\"https:\/\/ahrefs.com\/blog\/url-parameters\/\">URL parameters<\/a> are additions to a URL like ?tag=something. You may see some of these URLs in our index, but they\u2019re usually parameters that show different content. In many cases, pages with parameters can show the same content. We have many systems in place to consolidate URLs to <a href=\"https:\/\/ahrefs.com\/blog\/canonical-tags\/\">canonical<\/a>&nbsp;versions and additional protection for infinite crawl paths. Other tools may not make the same decisions or have the same protections in place. As a result, they may count essentially the same link many&nbsp;times.<\/p>\n<h3>Links we try not to&nbsp;store<\/h3>\n<p>Here are the links we do our best not to&nbsp;store.<\/p>\n<h4>Links from pages with URL parameters<\/h4>\n<p>As mentioned above, there are good and bad types of parameters. We try not to store the ones that are duplicated.<\/p>\n<h4>Links from pages in infinite crawl&nbsp;paths<\/h4>\n<p>These paths create an infinite number of possible URLs. Parameters are one way they could form but so are filters, dynamic content, and broken relative paths for links. As mentioned before, we have many protections in place for links on these types of pages so that they\u2019re less likely to show up in our reports. Respecting <a href=\"https:\/\/ahrefs.com\/blog\/canonicalization\/\">canonicalization<\/a> and the way we prioritize crawling pages are just two of those protections. Every index will have to deal with these infinite spaces, but there\u2019s potential for these pages to inflate link counts.<\/p>\n<h3>Links we don\u2019t&nbsp;store<\/h3>\n<p>Here are all the links we never&nbsp;store.<\/p>\n<h4>Links in PDFs or other documents<\/h4>\n<p>Google converts many document formats to HTML and indexes them as they would any other page. This means that they count links in these documents. I don\u2019t believe that any SEO tool currently indexes these links, but we probably should. I think that one day we will, but I\u2019m also concerned that the effort and resources required for this won\u2019t be worth it. According to Google Webmaster Trends Analyst John Mueller,&nbsp;<a href=\"https:\/\/twitter.com\/JohnMu\/status\/1221861121352773632\" target=\"_blank\" rel=\"noopener\">links in PDFs don\u2019t have any practical effect in web search<\/a>.<\/p>\n<h4>Links in iframes<\/h4>\n<p>Iframes allow another page to show inside of a page. Because of this, Ahrefs doesn\u2019t count links in iframes. However, they are shown to users, so other tools may count them even though the content technically belongs to a different page. Google may or may not count these&nbsp;links.<\/p>\n<h4>Links from pages not indexed<\/h4>\n<p>We drop these links.&nbsp;There are mixed messages from Google representatives on whether they use these in link calculations or not. Different tools may make different decisions.<\/p>\n<blockquote class=\"twitter-tweet\">\n<p dir=\"ltr\" lang=\"en\">something with noindex will never reach the serving index, but we will have the fetched copy for things like link graph calculation.\u2014 Gary \u9be8\u7406\uff0f\uacbd\ub9ac Illyes (@methode) <a href=\"https:\/\/twitter.com\/methode\/status\/1339633778831093761?ref_src=twsrc%5Etfw\">December 17,&nbsp;2020<\/a><\/p>\n<\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/p>\n<h4>Same links from multiple IPs<\/h4>\n<p>One fun fact about the web is that sites may serve the same page from multiple IP addresses. If this is the case, a link index may count the same link multiple times. We don\u2019t do this. We associate links with the pages they are&nbsp;on.<\/p>\n<h4>Multiple links to the same page from a single page<\/h4>\n<p>Currently, we only record one version of a link on a page. If you link to a page in the menu and then again in the body content, we will only count one of these links. We may change this in the future to give users more data, but this is the current state. Google will count all versions of links for passing <a href=\"https:\/\/ahrefs.com\/blog\/google-pagerank\/\">PageRank<\/a>&nbsp;but may only use one version\u2019s <a href=\"https:\/\/ahrefs.com\/blog\/anchor-text\/\">anchor text<\/a>.<\/p>\n<h3>Other link related items that impact the&nbsp;index<\/h3>\n<p>Understanding how we count links is one thing, but many other things can affect what does and doesn\u2019t get counted.<\/p>\n<h4>Number of links per&nbsp;page<\/h4>\n<p>I don\u2019t believe we have a limit for the number of links we count per page, but we do have a page size limit that may eventually impact the number of links we see. Google recommends <a href=\"https:\/\/developers.google.com\/search\/docs\/advanced\/guidelines\/webmaster-guidelines\" target=\"_blank\" rel=\"noopener\">no more than a few thousand links per page<\/a>.<\/p>\n<h4>Redirected or canonicalized<\/h4>\n<p>At Ahrefs, we trust all <a href=\"https:\/\/ahrefs.com\/blog\/301-redirects\/\">redirects<\/a>&nbsp;and canonical tags and consolidate links where websites tell us to. For Google, this is more complicated as they have many canonicalization signals that determine which page is the lead in a canonical cluster. We keep things simple because it\u2019s impossible to know how Google views every situation, and it would confuse our users if we treated canonicals and redirects differently every&nbsp;time.<\/p>\n<p>These links are tagged in our reports with \u201c301\u201d, \u201c302\u201d, or \u201cCanonical,\u201d such&nbsp;as:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"898\" height=\"434\" class=\"wp-image-130302\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/301-canonical-links-ahrefs.png\" alt=\"301 canonical links ahrefs\" srcset=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/301-canonical-links-ahrefs.png 898w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/301-canonical-links-ahrefs-680x329.png 680w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/301-canonical-links-ahrefs-768x371.png 768w\" sizes=\"auto, (max-width: 898px) 100vw, 898px\"><\/p>\n<div class=\"post-nav-link clearfix\" id=\"section1\"><a class=\"subhead-anchor\" data-tip=\"tooltip__copielink\" rel=\"#section1\"><svg width=\"19\" height=\"19\" viewBox=\"0 0 14 14\" style><g fill=\"none\" fill-rule=\"evenodd\"><path d=\"M0 0h14v14H0z\" \/><path d=\"M7.45 9.887l-1.62 1.621c-.92.92-2.418.92-3.338 0a2.364 2.364 0 0 1 0-3.339l1.62-1.62-1.273-1.272-1.62 1.62a4.161 4.161 0 1 0 5.885 5.884l1.62-1.62L7.45 9.886zM5.527 5.135L7.17 3.492c.92-.92 2.418-.92 3.339 0 .92.92.92 2.418 0 3.339L8.866 8.473l1.272 1.273 1.644-1.643A4.161 4.161 0 1 0 5.897 2.22L4.254 3.863l1.272 1.272zm-.66 3.998a.749.749 0 0 1 0-1.06l2.208-2.206a.749.749 0 1 1 1.06 1.06L5.928 9.133a.75.75 0 0 1-1.061 0z\" style \/><\/g><\/svg><\/a><div class=\"link-text\" data-anchor=\"Which domains get indexed?\" data-section=\"which-domains\">\n<h2>Which domains get indexed?<\/h2>\n<\/div><\/div>\n<p>In&nbsp;Ahrefs, we have the <strong>Referring domains<\/strong>&nbsp;report that shows all the domains linking to a website or webpage.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1600\" height=\"912\" class=\"wp-image-130304\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/referring-domains-report.png\" alt=\"referring domains report\" srcset=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/referring-domains-report.png 1600w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/referring-domains-report-680x388.png 680w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/referring-domains-report-768x438.png 768w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/referring-domains-report-1536x876.png 1536w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\"><\/p>\n<p>But how exactly do we count domains?<\/p>\n<p>You would think this would be an easy question to answer. It\u2019s just domain.com, right? Unfortunately, things are a little more complex as there are many ways to count domains. One option is to treat every registered domain as a domain\u2014which seems to be how Google aggregates them in <a href=\"https:\/\/ahrefs.com\/blog\/google-search-console\/\">Google Search Console<\/a>. Another is to treat every subdomain as a different domain. You could also aggregate some sections of a site and not others (what Google does), go by every section on a different tech stack, etc. There are many options.<\/p>\n<p>At Ahrefs, we have ~175 million domains post-vetting. The vetting process includes removing spam domains and breaking out some subdomains where we\u2019ve determined that different users control the different areas. We use a custom list for this, but there\u2019s a somewhat similar public list at <a href=\"https:\/\/publicsuffix.org\/list\/\" target=\"_blank\" rel=\"noopener\">https:\/\/publicsuffix.org\/list\/<\/a>.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"1396\" height=\"366\" class=\"wp-image-130299\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-domains.png\" alt=\"ahrefs domains\" srcset=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-domains.png 1396w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-domains-680x178.png 680w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-domains-768x201.png 768w\" sizes=\"auto, (max-width: 1396px) 100vw, 1396px\"><\/p>\n<p>It is important to note that different domain definitions can result in large variations of referring domains. Here are some examples of things that others, not Ahrefs, may count as separate domains:<\/p>\n<ul>\n<li><strong>Mobile versions subdomains<\/strong>&nbsp;(m.domain.com, mobile.domain.com, etc.)<\/li>\n<li><strong>Country\/Language subdomains<\/strong>&nbsp;(en.domain.com, fr.domain.com, de.domain.com, jp.domain.com, etc). There may be exceptions to this in our index, such as wikipedia.org, but this is not standard practice.<\/li>\n<li><strong>Random subdomains<\/strong>&nbsp;(support.domain.com, images.domain.com, etc.)<\/li>\n<\/ul>\n<p>Another decision backlink tool providers have to make is whether they should count some subfolders as different domains. For instance, I think most link indexes would count different blogs on well-known platforms (e.g., user1.blogspot.com, user2.blogspot.com) as different domains because different users control them. But why not do the same for sites like medium.com\/user1 or github.com\/user1? At Ahrefs, we don\u2019t currently do this, but there\u2019s a chance we may in the future where we know different people control each subfolder on a&nbsp;site.<\/p>\n<p>The point here is that there are many ways to count domains. That\u2019s obvious when you look at the varying figures from companies that count sites on the internet. <a href=\"https:\/\/www.verisign.com\/en_US\/domain-names\/dnib\/index.xhtml\" target=\"_blank\" rel=\"noopener\">According to Verisign<\/a>, there are 370.7 million registered domains in Q3 2020 across all TLDs. <a href=\"https:\/\/news.netcraft.com\/archives\/2020\/11\/30\/november-2020-web-server-survey.html\" target=\"_blank\" rel=\"noopener\">According to Netcraft<\/a>, there are 1,229,948,224 sites across 263,787,870 unique domains with 193.8 million active sites in November 2020. <a href=\"https:\/\/www.internetlivestats.com\/total-number-of-websites\/\" target=\"_blank\" rel=\"noopener\">According to Internet Live Stats<\/a>, there are roughly 1.8 billion websites with less than 200 million currently active. Each company clearly has a different methodology for counting domains.<\/p>\n<p>To recap, what we do at Ahrefs is take all the sites we know about and remove many spam and inactive domains, then add some for subdomains on sites like blogspot.com. That\u2019s how we come to our total domain count of ~175 million. Other indexes may do this differently and come up with different counts.<\/p>\n<div class=\"post-nav-link clearfix\" id=\"section1\"><a class=\"subhead-anchor\" data-tip=\"tooltip__copielink\" rel=\"#section1\"><svg width=\"19\" height=\"19\" viewBox=\"0 0 14 14\" style><g fill=\"none\" fill-rule=\"evenodd\"><path d=\"M0 0h14v14H0z\" \/><path d=\"M7.45 9.887l-1.62 1.621c-.92.92-2.418.92-3.338 0a2.364 2.364 0 0 1 0-3.339l1.62-1.62-1.273-1.272-1.62 1.62a4.161 4.161 0 1 0 5.885 5.884l1.62-1.62L7.45 9.886zM5.527 5.135L7.17 3.492c.92-.92 2.418-.92 3.339 0 .92.92.92 2.418 0 3.339L8.866 8.473l1.272 1.273 1.644-1.643A4.161 4.161 0 1 0 5.897 2.22L4.254 3.863l1.272 1.272zm-.66 3.998a.749.749 0 0 1 0-1.06l2.208-2.206a.749.749 0 1 1 1.06 1.06L5.928 9.133a.75.75 0 0 1-1.061 0z\" style \/><\/g><\/svg><\/a><div class=\"link-text\" data-anchor=\"Why we can\u2019t see all links\" data-section=\"why-we-cant-see-all-links\">\n<h2>Why we can\u2019t see all&nbsp;links<\/h2>\n<\/div><\/div>\n<p>As we find backlinks by crawling the web, we can only do so on sites we\u2019re allowed to crawl. If site owners block AhrefsBot in their <a href=\"https:\/\/ahrefs.com\/blog\/robots-txt\/\">robots.txt<\/a>&nbsp;file, we can\u2019t crawl their site. For example, if you get a backlink from website.com and website.com blocks AhrefsBot, we can\u2019t crawl their site and your backlink won\u2019t show up in Ahrefs. IP blocks, user-agent blocks from servers (different from robots.txt), server timeouts, bot protection, and many other things can also affect our ability to crawl some websites. Crawling the web at scale isn\u2019t&nbsp;easy.<\/p>\n<h2>We have multiple link indexes<\/h2>\n<p>Each tool has to make decisions about data storage and retrieval. At Ahrefs, we split our data into multiple indexes.<\/p>\n<ul>\n<li><strong>Live<\/strong>&nbsp;- the links we see that are still active on the web. This best represents the current state of the web and is what many of our users will find most useful.<\/li>\n<li><strong>Recent<\/strong>&nbsp;- links we have seen active on the web in the past 3-4 months.<\/li>\n<li><strong>Historical<\/strong>&nbsp;- all the links we have ever seen. This is going to be the most comprehensive list, but with many links that no longer exist.<\/li>\n<\/ul>\n<p>You can switch between indexes in our backlink and referring domain reports.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"860\" height=\"544\" class=\"wp-image-130300\" src=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-indexes.png\" alt=\"ahrefs indexes\" srcset=\"https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-indexes.png 860w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-indexes-672x425.png 672w, https:\/\/ahrefs.com\/blog\/wp-content\/uploads\/2021\/01\/ahrefs-indexes-768x486.png 768w\" sizes=\"auto, (max-width: 860px) 100vw, 860px\"><\/p>\n<p>Other indexes may choose to show all the data they have ever seen, and while this means they may show a lot of links, many of those links may not exist anymore.<\/p>\n<h2>Final thoughts<\/h2>\n<p>We wanted you, our users, to have more information on our index so that you can make informed decisions. We also want you to let us know if you think we should change things and&nbsp;why.<\/p>\n<p>If you\u2019re currently comparing link indexes or have questions about our data, feel free to reach out to us with any questions or for clarifications.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When building an index of the web, companies have to make many choices around crawling, parsing, and indexing data. While there\u2019s going to be a lot of overlap between indexes, there\u2019s also going to be some differences depending on each<span class=\"ellipsis\">\u2026<\/span><\/p>\n<div class=\"read-more\">Read more \u203a<\/div>\n<p><!-- end of .read-more --><\/p>\n","protected":false},"author":150,"featured_media":130424,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[414],"tags":[],"coauthors":[377],"class_list":["post-130306","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-data-studies","odd"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How Ahrefs Counts Links and Domains<\/title>\n<meta name=\"description\" content=\"Every backlink tool will store different links. 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