SEO Ranking Factors

Here is a complete list of SEO ranking factors that have been either been confirmed by Google or that we believe Google is employing.


Domain Ranking Factors

Domain Age
The domain age is likely an SEO ranking factor. The older the domain, the more trusted it is. This hasn’t been confirmed by Google, but many SEO’s believe this to be the case.

Country Domain Suffix
A country code top-level domain (, .ie, .ca) will help a site rank for that nation. However, it will certainly impede the site’s potential to rank internationally.

Keyword Appears in Domain
Having a keyword in your top-level domain or sub-domain acts as a relevancy signal, although not as powerful as it once was.

Exact Match Domain
Exact match domain (EMD) used to rank extremely well, however, Google caught on to this overpowered SEO ranking factor and now it probably has no benefit. If the site content is scraped or of low quality, it could be penalised by Google’s EMD update from 2012.


On-Page SEO Ranking Factors

Title Tag
Your keyword in your title tag is a ranking factor and tells Google what the page is likely to be about – a relevancy signal. Title tags that start with your keyword rank better than if it appears towards the end of the title tag.

Keyword in H1 Headings
Along with the title tag, Google uses the h1 heading tag as a relevancy signal.

Keyword in H2-h6 Headings
Having your keyword and associated keywords in subheadings help Google understand the structure of the site and is a small SEO ranking factor.

Keyword in Description
Although not a ranking factor in itself, because google highlights the keywords within a search query it will help click-through rate (CTR) which is a ranking factor.

Keyword in the URL
Very long URL’s and URLs which are not user friendly negatively impact search engine visibility. Whilst adding your keyword in to the URL is a relevancy ranking signal.

URL Structure
The URL structure (including categories in the URL) helps Google understand the site architecture, what the page may be about and the importance of a page.

When compared to URLs deeper down the site structure, those closer to the home page may have a higher authority.

Keyword in Content
Having the keyword appear in the content, and particularly within the first paragraph is a very important relevancy signal.

Term Frequency-Inverse Document Frequency (TF-IDF)
TF-IFD is a statistical measure that assesses the relevance of a word to a document in a set of documents.

This is accomplished by multiplying two metrics: the number of times a word appears in a document and the word’s inverse document frequency over a collection of documents.

It has a variety of applications, including automatic text analysis and scoring words in machine learning techniques for Natural Language Processing (NLP).

Google uses an advanced version of TF-IDF to understand what the page is about: The more frequently a word occurs on a page, the more probable the page is about that word. However, if the word appears too many times vs other articles of a similar nature, it may not look like a natural use of language.

Semantic Keywords
Instead of focusing solely on keywords, Google reads and can comprehend the general theme of a page thanks to the Google Hummingbird update.

Length of Content
The top-ranking results have an average word count of roughly 1,900 words and tend to cover the topic indepth.

Ideal lengths, on the other hand, vary depending on the topic, the keyword, and the level of competition. Google will be more concerned with how visitors interact with the material than with its length.

If a post has 1,900 words but visitors don’t spend much time on it (Dwell Time) or click the return button to move to another result, Google is likely to think that your lengthy content isn’t answering consumers’ questions.

Thanks to Hummingbird, Google can now better understand the topic of a webpage and not only the keywords. Google can also understand the overall topic of your website.

Duplicate Content on the Same Site
The search engine visibility of a site can be harmed by identical content appearing on the same site on different pages.

Grammar and Spelling
Correct spelling and grammar is a quality ranking signal.

Content Creation Date
Google favours content that has been recently published or updated, especially for time-sensitive queries.

Google displays the date of a page’s latest update for select pages to emphasise the relevance of this factor.

Content Historical Updates
How frequently has the content been changed in the past? Every day, every week, every five years? The frequency with which pages are updated effects SEO ranking factors.

Scraped Content
Some website owners employ content “scraped” from other, more credible websites in the belief that expanding the number of pages on their site is a beneficial long-term strategy, regardless of the content’s relevancy or distinctiveness.

It may even lead to a penalty.

Reading Level
Google estimates the reading level of a site – basic, intermediate or advanced. Google probably matches the reading level to that relevancy of the search query and user intent.

Table of Contents
A linked table of contents like the one above can assist Google in better understanding the content of your web page. It may also result in the sitelinks within Google Search.

Page Speed
Google Has confirmed page speed and core web vitals are a ranking factor.

User experience is also influenced by page speed. Pages that take longer to load have a greater bounce rate and a shorter average stay on page. Conversions have also been demonstrated to be harmed by longer load times.

AMP (Accelerated Mobile Pages)
AMP pages are small, fast-loading pages that give mobile visitors a more engaging experience.

It’s an open-source HTML framework that makes it simple to create fast-loading webpages that put the user first. It involves creating a stripped-down AMP copy of a webpage.

It’s possible that AMP is required to rank in the Google News Carousel’s mobile version.

Canonical Tag
A canonical tag (also known as “rel canonical”) tells search engines that a given URL is the page’s master copy. The canonical element prevents duplicate or “same” content from appearing on different URLs, which could cause problems.

The canonical tag, in practice, notifies search engines which version of a URL you want to show up in search results.

Image Optimisation
The file name, alt text, title, description, and caption can transmit relevancy signals to search engines.

However, alt text is given a higher priority by Google. They utilise it to figure out not only what’s on the image, but also how it relates to the text around it.

Outbound Links
Linking out to authoritative pages send Google trust signals. The outbound content that you link to also most likely sends Google relevancy signals about your page. Too many outbound links without rel=nofollow may “leak” PageRank.

Mobile Friendly
The mobile-friendly update or ‘Mobilegeddon’ came in April 2015. The main result of this change was that websites that display well on smartphones and other mobile devices were given precedence over those that don’t.

Mobile Useability
Websites that have a better user experience on mobile perform better in Google search than those that don’t. You’ll find a usability report tool in Google Search Console.

Hidden Text on Mobile
On mobile devices, hidden text may not be indexed (or evaluated as heavily) as fully exposed content.

Text hidden behind tabs, usually FAQs, may not be indexed.

Helpful Interactive Apps
Helpful on-page apps such as calculators or currency converters are an indicator of a page’s quality. These apps are also likely to increase dwell time and lower bounce rate.

Video on a page is also an indicator of the quality of a page and similar to an interactive app, will help with dwell time and bounce rate.

Internal Linking
Google uses links to discover new content on websites and to rank it in search results. A large number of links to a post or page indicates to Google that it is an important or high-value article. This applies to both internal and external links.

Internal links from authoritative pages have a greater impact than internal links from pages with no or poor PageRank.

The anchor text of an internal link acts as a relevancy signal.

Broken Links
Too many broken links on a page indicate to Google a low page quality or abandoned site.

W3C Validation
A well-coded website may be a quality signal.

Sitemap Priority
The priority of the page within the sitemap may influence the importance of the page.

Page Age
Although Google favours new, regular content, a page that has existed for a while that is updated on a regular basis may perform better than a newer page.

Page Layout
A page that makes the main content immediately visible likely outranks pages that don’t.


Site-Wide SEO Ranking Factors

Overall Content Quality
A site that has a lot of duplicate, scraped or thin content will most likely receive a penalty from Google.

Contact Information
Contact information and legal information on a website help with domain trust and is a quality SEO ranking factor.

Site Structure
A well-structured site with good architecture will help Google better understand the content, its relevancy and importance and therefore an SEO ranking signal.

Although a sitemap isn’t a ranking factor, a sitemap with priority information submitted in Google Search Console helps Google find and index pages.

Host Downtime
A site with a lot of downtime is likely a negative quality ranking factor.

Host Location
The website host physical location helps rank the site in geographic locations. A UK based host will rank better for UK based search queries.

It will also help with page speed for users within your target geo-location.

SSL Certificate
Google has confirmed a secure site using an SSL certificate is a ranking factor.

Duplicate Metadata
When it comes to helping search engines comprehend the context of your website, duplicates are an issue; how should Google prioritise displaying one page when you have the same fundamental description on numerous other pages?

It may also mean there is a lack of descriptiveness or focus throughout the site.

Breadcrumb markup in the body of a web page is used by Google Search to categorise the material on the page in search results.

User Experience
By reducing time on site, pages visited, and bounce rate, a site that is difficult to use or navigate might effect rankings indirectly.

Google has always advised to concentrate on the user first with a well-designed website, rather than clicks.

Google Analytics
It’s never been confirmed, however, we believe that having Google Analytics installed on your website helps Google with data such as bounce rate, referring traffic, time on site, etc.

Reviews on sites such as Google Business, or Trust Pilot are probably a quality and trust rank signal.

Structured Data
Google employs structured data to provide more information to organic listings. Structured data provides Google with detailed information about the page’s content.

According to a study conducted by Schema App, enhanced organic listings with structured data provide a 20% higher average click-through rate (CTR).

Content Authorship
The existence of author names and the inclusion of author biographies could give a trust ranking factor.

Hacked Website
Google can deindex your entire site if it deems it a risk for its users.


Backlink Ranking Factors

Number of Referring Domains
An important ranking factor. You’re “worthy of amplification” if a lot of people are directing their readers to you. The number of domains linking to yours from the same IP address is less effective.

Referring Domain Age
An aged domain has more authority than newer domains.

Anchor Text
The anchor text used within the backlink is a relevancy signal. However, it can also be a webspam signal if Google deems it to be unnatural looking, if multiple backlinks use exact match anchor text, for example.

Backlink Image Alt Text
The image alt text acts as the anchor text if the backlink is an image.

Authority of the Referring Domain and Page
The referring domain’s overall authority, as well as the PageRank of the page on which the backlink resides, are both crucial ranking factors. A backlink from an authoritative site will pass more PageRank than an unknown site.

Spammy backlinks
Backlinks from spammy websites or websites associated with spam (bad neighbourhoods) may result in a penalty or negative ranking effect.

Backlinks from Ads
Advertisement links should either be Nofollowed or have the rel=sponsored tag.

Nofollow Links
According to Google, Nofollow links do not pass PageRank. However, according to recent publications, Google uses Nofollow links as a ranking factor, thus just because a link is Nofollow doesn’t mean it doesn’t have any significance.

Plus, a particular percentage of Nofollow links can also reveal whether a link profile is natural or unnatural.

Backlink Diversity
A high percentage of your links coming from a single source, eg blog comments could be a sign of an unnatural backlink profile. Links from a variety of sources, on the other hand, indicate a natural link profile.

Contextual Backlinks
Links embedded in an article have more authority than those found elsewhere on the page, for example in the footer or sidebar.

Referring Page Quality and Length
A backlink from an in-depth 2000 word, well-written article passes more value than a 100-word article.

Surrounding Text
Google can also decipher the surrounding text and use this as a relevancy ranking factor.

301 Redirect
A 201 redirect of a page loses approximately 20% of its PageRank.

Link Title
When 56k modems were common and page speeds were poor, the link title attribution was employed. When a user hovered their mouse over a link, a description appeared, explaining what the link page was about. The link title attribute may still provide a very faint relevancy signal to Google.

Backlink Domain Suffix
Getting links from specific country domains such as may help Google decipher where to better rank your site geographically.

Backlink Topics and Categories
The topics from the backlinking domains and backlinking pages are a relevancy ranking factor.

A page with increasing backlink popularity shows page authority.

Backlink Age
Older backlinks are considered more trustworthy.

Amount of Outbound Backlinks
Link Juice gets diluted by the number of links are on a page. A backlink on a page with hundreds of outbound connections conveys less PageRank than a backlink on a page with only a few.

Backlinks from Web 2.0 (Forums and Comments)
Backlinks from forums and comments from blog posts have little to no value.

Sitewide Backlinks
Sitewide backlinks, such as those found in a website’s footer, are counted as a single backlink.

Rapid Backlinks Spike
A rapid spike of links suddenly pointing to your site is a dead giveaway that the links are fake.

Backlinks with “Poison” Anchor Text
Backlinks with “poison” anchor text such as gambling, or pharmacy keywords are a sign of webspam.

Overall Backlink Profile
A site with a “natural” link profile will rank higher and be more resistant to changes than one that has plainly utilised black-hat link-building tactics.


User Signals

Click-Through Rate (CTR)
Pages with a greater click-through rate from Google’s organic search results provide a stronger relevancy signal to Google for that search query.

There may also be a sitewide domain CTR quality score, favouring sites that have an overall higher CTR.

Bounce Rate
A bounce rate indicates that the page Google served the user didn’t answer their query. Pages with a high bounce rate tend to get demoted within Google.

Sites with a lot of traffic are most likely of a high quality or valuable brand. The more traffic, the higher the authority.

Sites with a lot of repeat traffic may also receive an authority boost for the same reason.

Dwell Time and Time on Page
The period of time between when a user clicks a search result and when they return to the SERPs is known as dwell time. It’s an excellent sign of user intent and relevancy.

The longer you stay on a page after a search query, the more likely it is that the page has answered your query.

Comments on a Page
Pages with a high number of comments may indicate high levels of user participation and therefore content quality.


User Intent Signals

Browsing History
Websites that the user have visited in the past, get an uplift within Google Search.

Search History
By looking at previous searches, Google will try to figure out what the user’s goal is and promote pages based on that.


Other Signals

Big Brands have been given an authority boost for their brand and product associated keywords.

Your Money or Your Life
Google’s term “Your Money or Your Life” (YMYL) refers to pages that Google believes may have an influence on “users’ future happiness, health, financial stability, or safety.”

Ecommerce websites, medical websites, news websites, and a variety of other types of websites all fall within the YMYL category and are held to a higher “Page Quality” standard as a result.

Local Searches
Google will display local results as a priority for local searches.

Social Signals
Sites with lots of social likes and followers tell Google you have a popular brand.

The number of times a brand appears across the internet and within articles could be a ranking factor.



The most crucial thing to keep in mind is that reaching the top of the search results pages takes time.

If you optimise your website for numerous ranking factors now, it will not be at the top of the search results tomorrow.

Do you need SEO assistance? Contact us to see if we can help achieve your goals.


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Posted by Gareth Allen

Over the past 20 years, I have worked on magazine/newspaper design & pre-press production, advertising, POS, DM, brand creation and guardian. I'm a front end-digital designer (html/css), SEO & SEM with a passion for digital marketing.