An in-depth guide to Google ranking factors
In SEO, Google’s ranking factors are the stuff of legend.
There are rumored to be more than 200 signals which inform Google’s rankings (although this statistic originated in 2006, so it’s probably safe to say things have changed a bit since then), and the exact factors which make up this list, as well as their order of importance, is the subject of perennial debate.
While we at Search Engine Watch can by no means lay claim to a complete list of Google ranking factors (and anyone who says they can is lying to you – yes, even if they’re from Google, probably), we’ve delved into the subject a fair bit.
Last year our intrepid editor Christopher Ratcliff wrote a ten-part series examining a number of important Google ranking factors in detail. This guide will summarize the key insights from that series for your referencing convenience, with links to the full explanations of each ranking factor.
From content freshness to content quality, internal links to backlinks, we’ve covered off the major points that you need to hit for a solid Google ranking, and how to hit them.
So without further ado, let’s get started.
- Part 1: On-page factors
- Part 2: Keywords
- Part 3: Quality content
- Part 4: Content freshness
- Part 5: Duplicate content and syndication
- Part 6: Trust, authority and expertise
- Part 7: Site-level signals
- Part 8: Internal links
- Part 9: Outbound links
- Part 10: Backlinks
- BONUS: RankBrain
Part 1: On-page factors
The first part of our guide to Google ranking factors looks at the simple, technical elements that Google uses to rank your page: title tags, H1 tags and meta descriptions.
These are all elements that you have total control over, and have a significant effect both on how Google ranks your site and how your site appears in the SERP. Therefore, it’s incredibly important to learn how to optimize them properly.
Some key points on how to optimize your title tags, H1 tags and meta descriptions for search:
- Include any keywords you want to rank for in the title tag. The closer to the start of the tag the keyword is, the more likely that your page will rank for that keyword
- With that said, make sure your title tags are written for humans – that means they still need to make logical sense and not just be stuffed full of keywords
- Don’t duplicate title tags across your website, as this can negatively impact your visibility
- Your target keywords should also be in the H1 tag, but your H1 can differ from your title tag
- You can generally only use one H1 tag per page, but H2 and H3 tags can be used to break up your content further
- While meta descriptions are not strictly a ranking signal, a good meta description can vastly improve click-through rate, so make sure you use it wisely!
For even more depth on how to write title tags and meta descriptions for SEO, check out our two separate guides:
Part 2: Keywords
Part 2 of our ranking factors guide looks at that eternal subject of SEO discussion: keywords.
Although the role of keywords in SEO has changed greatly since the early days of search, with the evolution of long-tail keywords and natural language search, the humble keyword is still one of the fundamental building blocks of search optimization, and an important Google ranking signal.
But as we covered in the last section, just because keywords are important doesn’t mean you should stuff them in like crazy. Here are some highlights from our guide to Google ranking factors about how to use keywords wisely:
- Keyword relevancy and placement is far more important than frequency. Your keyword or key phrase should appear in the first 100 words of your page, if not the first sentence
- Google prioritizes meta information and headers first, then body copy, and finally sidebars and footers
- Try to ensure the key phrase is an exact match to what the searcher will type into a search engine. This means phrasing your keywords in a conversational fashion if you want to optimize for natural language search queries
- Excessive repetition of keywords, and using keywords that are irrelevant to the rest of your content, are likely to earn you a penalty
- Having keywords in your domain URL can also give you a small SEO boost.
Part 3: Quality content
You’ve no doubt heard the phrase “quality content” thrown around as a way to get your blog or site ranked highly by Google: “Produce quality content”.
Well, that’s all very well and good, but what does it mean in practical terms? How can you know if the content you’re producing is high-quality enough for Google?
In Part 3 of our guide to Google ranking factors, we give 14 tips for gauging the quality of your content, covering everything from spelling and grammar to readability, formatting and length. Here are a few of our pointers:
- As we’ve covered previously, make sure your content is written to appeal to humans, not just algorithms, and don’t saturate it with keywords
- Check the readability score of your content with the Flesch reading ease test, and aim to get above 60%
- Keep your sentences and paragraphs short, and break them up with line breaks (white space makes much for a much nicer reading experience on mobile) and subheadings
- While you want your sentences and paragraphs to be short, your overall content can be as long as you fancy – in-depth content is a big indicator of quality.
Part 4: Content freshness
Continuing with on-page content signals, how recently your webpage was published is also a ranking signal – but different types of searches have different freshness needs, such as searches for recent events, hot topics, and regularly recurring events.
Google’s algorithms attempt to take this all into account when matching a search with the most relevant and up-to-date results.
Last year, Moz published a comprehensive look at how freshness of content may influence Google rankings, which forms the basis of our insights in Part 4 of the guide to Google ranking factors. Some key takeaways include:
- A web page can be given an immediate “freshness score” based on its date of publication, when then decays over time as the content gets older. Regular updates to the content can help to preserve that score
- An increase in the number of external sites linking to a piece of content can be seen as an indicator of relevance and freshness
- Links from “fresh” sites can help pass that freshness on to your content
- The newest result isn’t always best – for less newsworthy topics, an in-depth and authoritative result that’s been around longer may outrank newer, thinner content.
When is it acceptable to republish someone else’s content on your website, or to re-use your own content internally? The SEO community has a shared horror of accidentally running afoul of a “duplicate content penalty”, and advice abounds on how to avoid one.
To be sure, stealing and republishing someone else’s content without their permission is a terrible practice, and doing this frequently is an obvious sign of a spammy, low-quality website. However, as Ann Smarty explains in her FAQ on duplicate content, there is no such thing as a “duplicate content penalty”. No-one from Google has ever confirmed the existence of such a penalty, and nor have there been any “duplicate content” algorithm updates.
So what are the dangers with publishing duplicate content? In short, they concern search visibility: if there are multiple versions of the same post online, Google will make a call about which one to rank, and it will likely have nothing to do with which was published first, but rather with which site has the highest authority.
In the same vein, if you have multiple versions of the same internal content competing for rankings (this includes separate desktop and mobile versions of the same site), you can wind up shooting yourself in the foot.
How can you avoid all of this? Part 5 of our Google ranking factors article covers how to manage duplicate and syndicated content to make sure that Google only indexes your preferred URL. Some points include:
- Setting up a 301 redirect if you have duplicate content on your own site, to make sure Google indexes your preferred page
- Using a responsive website instead of a separate mobile site
- Using a rel=canonical tag or a meta noindex tag on syndicated content to tell Google which article is the original.
Part 6: Trust, authority and expertise
We know that websites with a high level of authority carry greater weight, particularly when it comes to link-building campaigns. But exactly how does Google evaluate your website’s levels of trust, authority and expertise?
In Part 6 of our Guide to Google Ranking Factors, we examine the factors that make up your site’s Page Quality Rating, as well as how Google calculates authority, trust and expertise. Some key points include:
- Content quality, content amount, and website information are all factors in your Page Quality Rating
- A logical site architecture can help with a higher level of authority
- Starting a blog can help showcase that your business is relevant and trustworthy – as well as helping with content freshness
- Negative customer reviews won’t necessarily impact your Page Quality Rating, particularly if you have a high number of total reviews. Google tends to check reviews for content, rather than the actual rating.
Part 7: Site-level signals
Moving away from on-page content, Part 7 of our Guide to Google Ranking Factors looks at site-level signals.
What factors does Google take into account at a site level that can affect your ranking? Here are a few…
- HTTPS: Google announced in 2014 that it was starting to use HTTPS as a “very lightweight signal”. While it’s unknown whether it has strengthened since then, using HTTPS is also just good practice generally, particularly if your website handles financial transactions
- Mobile-friendliness: Mobile-friendliness has been a significant factor in Google search results ever since the initial “mobilegeddon” update of 2015, and the signal has only strengthened since then
- Site speed: Take the time to assess and optimize your site speed, particularly on mobile, and you are likely to find that your search ranking improves.
Part 8: Internal links
Parts 8, 9 and 10 of our ranking factors guide all deal with the nervous system of the internet: links. How do different types of links help your site rank well in search?
First: internal links. According to Jason McGovern of Starcom, internal linking is one of the few methods we can use to tell Google (and visitors) that a particular page of content is important. So how should you go about linking internally to other pages of your website?
Part 8 covers off how internal links can help your site improve its metrics and user experience, including “hub pages” and how to build them.
Once you’ve digested the important points, be sure to check out our full guide to Internal Linking for SEO: Examples and Best Practices.
Part 9: Outbound links
Outbound, or external, links are links pointing outwards from your site to another website. They pass along some of your own site’s ranking power (without any detriment to you, unless the links go to a super spammy website) to the site you’re linking to.
But how does this benefit you? Why should you be giving out what are essentially link juice freebies to other sites?
In actual fact, as we reveal in Part 9 of our Guide to Google Ranking Factors, outgoing links to relevant, authoritative sites benefit your ranking. Other key points about outbound links and SEO include:
- Pagerank retention is a myth – it’s not possible for your site to ‘leak’ link juice by having more external than internal links
- In fact, outbound links count as a trust signal – if you’re linking to references to back up your data and research, you’ve clearly done your work properly and can be trusted
- Affiliate links are also fine, but make sure you use a nofollowmeta tag in accordance with Google best practice.
Part 10: Backlinks
Why are backlinks (links from a third party back to your site) important to SEO? Well, as we just covered, external links from your own site to another website pass along some of your ranking power – so the reverse must also be true.
Links back to your site from elsewhere online are an important way to improve your search ranking; in fact, as revealed by Andrey Lipattsev, Search Quality Senior Strategist at Google Ireland, last year, links pointing to your website are one of the top three ranking factors.
Small wonder, then, that there is a booming trade around link-building in SEO – both in advice on how to build links, and in buying and selling links themselves. However, paid link-building is considered black hat SEO and is likely to incur a penalty.
Google has clamped down on different types of paid links, such as links on blogs exchanged for free gifts, at various times. This has made many SEOs wary of the practice of link-building altogether. But Google has nothing against link-building in principle – on the contrary, Google relies on links to know what websites are all about, and how much preference to give them in certain searches.
So how can you go about earning backlinks the right way? Here are some pointers from Part 10 of our Guide to Google Ranking Factors:
- Needless to say, the number of individual domains referring to your website is an important factor in Google’s algorithm – but so is their authority. Having fewer, authoritative backlinks is worth more in terms of SEO value than having lots of low-quality links (except in local SEO, as Greg Gifford will tell you).
- Backlinks from relevant sites in your niche are also worth significantly more than irrelevant sites or pages
- Links from a diverse range of websites are good, as too many links from the same domain can be seen as spammy
- Links within long-form, evergreen content are also more valuable than links in short, news-based posts.
BONUS: RankBrain and SEO
While not an official part of our Guide to Google Ranking Factors, I thought I’d include Dan Taylor’s excellent guide to RankBrain and SEO as part of this round-up, as Google has officially named RankBrain as one of the three most important signals that contribute to a website’s ranking.
In his guide, Dan Taylor breaks down and untangles how RankBrain works, as well as what machine learning is, and the concepts that underpin Association Rule Learning (ARL).
He then explains “optimizing” for RankBrain (hint: it’s not as complicated as you might believe) and how RankBrain differs from “classic algorithms” like Panda and Penguin.