Are links on other websites that point to your site an important Google-search ranking factor?\nThe answer used to be blatantly obvious, and for some, it still is. Google, however, made major changes to its search engine algorithm during the past few years. The company also changed the way it displays search results. Then there are mobile search results, which can be different from desktop results, the possible impact (or not) of social media shares, the emergence of Google's RankBrain artificial intelligence (AI), and many other factors that come into play.\nIt's all enough to cause confusion and lead to questions about today's most important search engine ranking factors. We interviewed a set of SEO experts for their takes on the most important ranking factors. They're not listed in order of importance, because not all of the experts agreed on the degrees of importance for factors. However, the consensus is all digital marketers, SEO experts and other search pros should focus on the following six SEO ranking factors.\n6 key search-ranking factors\n1. Content relevance and SEO rank\nGoogle ultimately became the dominant search engine because it is adept at displaying, on the first page of search results, the most relevant content that matches a keyword query. Eventually, users came to assume the search engine only shows the most relevant results first, a behavior that web-usability consultant Jakob Nielsen dubs, "Google Gullibility."\nContent relevance is often assumed or overlooked in studies of ranking factors, but it's still the most important factor, according to Eric Enge, CEO of Stone Temple Consulting, which offers content marketing, SEO, social media, and Google-penalty recovery services.\nRelevance is often presumed to be "on" or "off," so content is either relevant or irrelevant to a query. "But that's not really the right view in my opinion," Enge says. "You can't assume that relevance is a binary factor, where you assign a zero score if it's not relevant and a 1 score if it is relevant. True relevance scoring would be on a sliding scale, ranging from 0 to 1, with any possible value in-between. The content with the lower score would need to score somewhat higher on other metrics to outrank the [higher score]."\n2. Inbound links and SEO\nGoogle made a number of tweaks during the past year, including the rollout of RankBrain and a second mobile-friendly update, but the core ranking factors remain much the same, according to Jayson DeMers, founder and CEO of AudienceBloom, a content- and social-media marketing firm. "The quality of\u00a0inbound links pointing to your domain or page\u00a0is still the most important ranking indicator."\nLinks have always been key to high Google ranks. During its early days, Google touted its PageRank technology as an important competitive differentiator. PageRank is Google's "numeric rating of how important it considers pages to be," according to Search Engine Land. Google said in 2011 that PageRank "works by counting the number and quality of links to a page to determine a rough estimate of how important the website is. The underlying assumption is that more important websites are likely to receive more links from other websites." As of earlier this year, Google no longer shares PageRank scores publicly, but it still uses them in ranking calculations, Search Engine Land says.\nStone Temple Consulting recently performed a research study to answer the question: "Are links still a powerful ranking factor?" All of the details are available in the company's related blog post, but the gist is that provided the content is relevant and a site doesn't have technical problems or quality issues, links are still highly important. And "authority" is Enge's No. 2 most important ranking factor after content relevance, though it's primarily driven by the quality and diversity of backlinks, he says.\nSEO consultancy Backlinko recently posted the results of its search engine ranking factors study, based on a million Google search results. Backlinko found that "the number of domains linking to a page correlated with rankings more than any other factor." Backlinko also concluded that a site's overall link authority, as measured by Ahrefs Domain Ratings, "strongly correlates with higher [search] rankings."\nRand Fishkin, founder of Moz, which offers SEO and other software tools as a service, says page-level link features are the No. 1 search engine-ranking factor today, assuming a site's content is relevant. These features include Google's PageRank, the quantity of linked root domains, quality of the link sources, and trust metrics. Every other year, Moz releases its own search engine ranking factors survey, and in the last survey for 2015, page-level link features were the No. 2 ranking factor, just slightly below domain-level link features.\n3. Content quality and SEO rank\nGoogle wants to deliver not only the most relevant content, but also the highest-quality search results. And quality can be measured in a variety of ways, according to Enge, including proper grammar and spelling, reading level, comprehensiveness \u2014 how well the content covers the spectrum of user needs related to the query \u2014 uniqueness, and a lack of negative signals, such as excessive keyword repetition. (The Content Marketing Institute's blog offers more information in, "How Google judges quality and what you should do about it," and, "What quality content is, and how to help your clients create it.")\u00a0\n"Marketers and SEO professionals should still focus on developing the best content they can to attract quality inbound links to their content, and that usually means\u00a0executing a solid content marketing strategy," says DeMers. "It's harder to stand out these days due to increasing competition in the content sphere, so if there's one change I can recommend \u2026 it's investing more to make sure your content is truly remarkable, even if that means creating less content overall."\nBacklinko's survey results found that "publishing focused content that covers a single topic may help with rankings," and that "longer content tends to rank higher in Google's search results. The average Google first page result contains 1,890 words." And a separate study from BuzzSumo and Moz found that long-form content "of over 1,000 words consistently receives more (social media) shares and links than shorter form content."\nSearchmetrics, an enterprise SEO and content marketing service provider, ranked content quality as the third most important element in its 2015 study of search ranking factors and rank correlations. Among the factors that can influence such ranking are keywords, in the body of the copy, in internal and external links, and in meta-descriptions; word count; and relevant terms.\n4. Technical issues and SEO\nLike content relevancy, technical issues are sometimes overlooked in SEO ranking factor studies. Technical issues, however, can prevent a site's content from ranking as highly as it could for relevant keyword queries \u2014 or keep it from ranking at all.\nCommon technical issues include duplicate content, dubious inbound links, poor navigation, and improper redirects. Google's goal is to deliver a positive user experience, so content on sites with architecture problems won't likely earn high ranking. "You have to solve those problems if you want to play the SEO game," Enge says.\nIn fact, technical issues ranked as the No. 1 most important factor to mitigate in Searchmetrics' study. Technical issues aren't just about problems in a website's structure, however. Technical on-page factors that can play a role in rank include whether or not content has a strong meta-description, if it uses H1 and H2 tags, and whether a site is encrypted via HTTPS. "HTTPS is becoming more relevant and even a ranking signal for Google \u2014 but it is not necessary for every site," the Searchmetrics report says. "Encryption is primarily important for sites with purchasing processes or sensitive client information to increase trust and conversion rates."\n5. User engagement and SEO rank\nDoes your content truly engage website visitors? If so, Google may reward you with a higher search ranking. Unfortunately, it's unclear how exactly Google measures user engagement. "I don't think anyone in the industry has a good handle on what user engagement measurements might be," Enge says, adding that he doesn't think click-through rates are a direct ranking factor.\nFor some pages, high bounce rates are a positive signal, according to Enge. When visitors land on contact pages in search of phone numbers and then click away, for example, that's a satisfactory user engagement. "But I do believe Google is looking at user engagement in some ways," Enge says. Google software engineer Paul Haahr confirmed as much in a March 2016 presentation, in which he said Google leverages user engagement to evaluate the quality of its ranking algorithms.\nMoz's Fishkin says user interaction and engagement, along with usage-data signals, are among the top SEO ranking factors. Such signals include clickstream analysis, which collects, analyzes and reports aggregate data on the pages site visitors see and in what order, and visitor traffic. In its beginner's guide to SEO, Moz outlines some user engagement metrics, and provides an explanation of how usability and user experience impact search rankings.\nSearchmetrics lists user experience as its No. 2 ranking factor, based on elements such as the number of internal links and images, responsive design \u2014 when a website adjusts to both mobile and desktop screens \u2014 and time spent on site.\n6. RankBrain and SEO\nIn March 2016, a Google search executive said RankBrain, links and content are the three top ranking factors, according to Search Engine Land. RankBrain uses AI to help Google "interpret the searches that people submit to find pages that might not have the exact words that were researched for," Search Engine Land says.\nBut some SEO professionals aren't convinced RankBrain is such an important factor. Google has said many times that RankBrain has a larger impact on long-tail queries, according to Enge. (Long-tail queries are highly specific search phrases with multiple words.) RankBrain runs on all queries, he says, but it doesn't impact broad or generic keyword search terms at all. Instead, it impacts keywords terms that are a bit more complex "infrequently," and RankBrain affects long-tail keyword phrases "fairly often," Enge says.\nSEO tips and best practices for 2016\n1. Don't overemphasize social media shares\nAfter Google+'s fall from grace, social signals lost a lot of search sway, especially for personalized results, according to Moz's Fishkin. And Enge points out, "social media sources can be shut off at any time, so Google doesn't want to make it part of their core algorithm."\n2. Ranking factors are intertwined\nSome misconceptions about ranking factors come from the idea that site owners can make a handful of changes or tweaks to pages and quickly see them rank, according to Holly Miller, a Searchmetrics SEO expert and professional services manager. "There are a lot of factors at play," she says. "A lot of the technical and content\u00a0elements\u00a0have to work together in concert to provide a superior user experience. It's ultimately about asking yourself,\u00a0'Does this content help the user accomplish X?'\u00a0Or\u00a0,'Does this content answer their question?'"\u00a0\n3. Always keep user experience in mind\nUsability, user experience, speed, and the ability to deliver unique value are crucial to SEO, according to Fishkin. "These were often the domains of other marketing and website professionals in the past, and SEOs merely helped with more technical and keyword-based on-page and off-page signals," he says. "But today, to succeed long-term in search, you need these elements of stickiness and remarkability."