Onpage SEO: What is it?
Onpage SEO is basically everything that you do on your website to make your site and/or subpages rank on Google. You can think of on page SEO as basically making sure that google understands exactly what your page is about.
If you look back in time the most basica versions of onpage SEO used to be adding relevent keywords that you wanted to rank for into your keyword meta tags field. Of course today this keyword meta tag is all but obsolete because Google realised that it was open to major abuse and manipulation so they started looking for other methods of detecting what a page was about.
How Google use onpage factors to determine a pages relevence for any keyword
So the whole point of onpage SEO is to make sure that Google understands what your page is about. Because we know that Google is looking at each page and trying to determine through the use of algorithms what a page is about and how relevent that page is to any keywords or phrases that are being searched for in Google. That predetermined relevance will then be used as one of many factors when deciding where to list that page within the search results.
Basic Onpage factors
First of all its a good idea to understand the basic onpage SEO factors - what you need to do in theory to optimize a page for a particular keyword or phrase.
For this part of the guide I am using some of the popular sources for onpage grading - for example the Moz onpage grading tool and the wordpress plugin Yoast SEO.
I have also taken some inspiration from a great guide here on BHW by PHPBuilt.
Keyword in URL
This involves having the keyword in the URL of your page. So for example if your article is on a sub page of your site and your main keyword is blue widgets then you might have the following URL -
http://domain.com/blue-widgets
Keyword in Title tag
The title tag contents will depend on the type of site that you have but if you are using wordpress then the title tag is normally made up from your websites main title or name followed by your pages title (The title that you put in to wordpress when you create the article).
Keyword in H1 tag
This is the text that is in between your H1 tags (You should only have one set of these tags on your page) - <h1></h1>. In wordpress this is normally made up from the title that you give your page or post.
Keyword in H2 tag
The same as above but for your H2 tags (your first sub-heading after you main (h1) page heading).
Keyword density in body
This is the number of times that you include your keyword within the body of your article. - well technically its the number of times that it appears on the page, so keep this in mind because if you have your keyword in your title and maybe your categories as well then this percentage will be bumped up.
Anyway, as per PHPBuilt's guide keyword density should be somewhere around 0.8 - 1.1% for a single word phrase and 0.5 - 0.7% for a 3 word phrase.
The idea behind this concept is making things look natural - if your keyword is widgets then it would seem likely that it be mentioned more in the content than if your keyword was blue widgets that form a circular shape when connected - the later being such a lengthy phrase it might seem unnatural to google if it appeared very reguarly within a page.
In the same respect you might expect a higher density for common words and a lower density for very uncommon words. For example if you were trying to optimize your article for the word cars then you might have a higher keyword density simply because that term is more common in general.
It is sensible to assume that Google would base keyword density checks on the density of keyword in comparison to the density of that keyword elsewhere on the internet in general - so taking the cars keyword as an example, for arguements sake lets say that keyword appears on the web 1% of the time - because it would be mentioned in loads of different sites and pages and covering a broad range of subjects. So when Google are trying to rank a page for the specific term cars they might look for a higher percentage of say 2% for that term - this would essentially cover the standard 1% that it is mentioned anyway and then an additional percentage of mentions for a page that is about that specific topic and no other related topics.
Conversly if Google were looking at the relevence of a page for a more specific keyword like cars with slick tires it might be the case that the term appears in general on the web only 0.1% of the time - because its a more specific keyword/phrase. And so when looking for sites that specifically relate to that exact topic they might expect a density of only 0.5% - which would be a lot higher than the average but lower than a density for a more common term like cars.
Anyway, in summary the keyword density can change depending on your niche, your keywords and how regularly they occur elsewhere on the web.
Keyword in bold / EM
This is a tactic that has been popular and involves putting in bold a mention of your keyword within your articles text. In theory this shows Google that your article is emphasising that keyword and thus shows google that the article is all about that keyword.
Keyword variations
These are very important and I will take some more about them below. Basically keyword variations are the different words that would be associated with your main keyword. So for example if your main keyword you are trying to optimize your page for is cars then related keywords might be automobiles, fords, vehicles, trucks etc. Depending on your actual keyword you might consider related terms to be ones that are very closely related or you might consider using broadly related terms as well - it depends how specific your keyword is and how many variations or alternatives there are.
Keyword in meta description tags
The meta description is something that you declare in the head of your article and it is something that Google will often use as the description for your page in the search results - the bit that appears below the title of your page in the results.
In wordpress you cant normally see or edit this description but if you install a plugin such as Yoast SEO then you will be given the option of editing the description as you create each page and/or post.
the theory is that having your keyword in your description shows additional relevence to Google.
Overall article topic
This can be tied in with the use of related keywords. There has been lots of talk recently about how Google looks for the overall relevence of a keyword to your page, and also about the overall subject of a page. You can manipulate or optimize this factor by included related keywords and phrases.
The theory here is that Google will often estimate the overall subject matter of a page through various means and then they will rank that page for a particular keyword even though that keyword may not neccesarily appear in the content of the page.
To back this up, there was a recent article published by ahrefs here, that showed up to 75% of pages ranking in the top 10 for Google dont have a single mention of the exact match keyword in the body of the text. This is a pretty cool figure and really should drive home the point that Google are looking at much more advanced techniques when they decide what a page is about and what it should be ranking for.
Image alt tags
The alt tags of an image are the text that can be used in place of the image - for example on a browser that doesnt render images, or for someone that cannot see and is using a screen reading software.
Adding your keyword in the alt tags for images on your page can also help to promote the relevence of that keyword within your page.
Technical perfection
Anyway, if you follow all of the tips above then you will have a technically perfect onpage SEO - if you run a page like that through moz on page grader or you check it with yoast SEO plugin for keyword optimization then you will get an A or a green light.
However, as I just mentioned and as ahrefs study of 2 million pages confirmed there is a lot more to it than this.
My theory is that just in the same way that Google realised that the meta keywords tag was easy to manipulate, they are also realising that onpage optimization is also very easy to manipulate.
Not only that, but I think they are also realising that if they really want to give users the most relevent information they need to look beyond simple keyword checks such as those mentioned above.
And so Google are going to be developing and relying on much more complex techniques and algorithms that are ultimately trying to understand what a page is about. The way that Google and other search engines do this is through semantic analysis - there is a good explanation of it here -
http://boomtrain.com/understanding-semantic-analysis/
If you want to manipulate this algorithm then its all about using related keywords. The way to do this is to take your main keyword and then brain storm all of the related keywords - think about it like what other ways of saying that keyword are there, what other terms might users be typing in when they are really looking for information about that keyword?
You can then take all of these related keywords and apply all of the above techniques to them. So for example, you might put one of those related keywords in bold, you might use another one of those related keywords in your h2 tag and so on.
Equally, if you are trying to rank for a keyword that doesnt read naturally in an article - like for example blue widgets big, then you might not include that phrase at all, least of all in your main heading. You might instead use the term big blue widgets in your heading. Google will know that these terms are related through its use or semantic analysis and it will also likely know that big blue widgets makes more sence than blue widgets big and thus that you are trying to manipulate the results if you are using the later as your title.
You can see the evidence of this if you search for the term on page SEO. YOu will see that the second result does not even include that phrase in its title (Thanks ahrefs for pointing that one out). This just shows that Google is smarter than that.
Other onsite factors
As well as optimizing your page as per the guidelines above there are other ways that you can optimize your site in general for your keywords.
Inter-linking
This is a very good practice which involves linking your own pages between eachother. For example if you have a page about cars then you might link to that page from another page on your site that is about trucks. Just like a backlink from an external site gives more credit to the page that it links to, so does a link from another page within your own site. This is just confirming to Google that the page is about that topic.
Reafirming relevence by other means
You can also reafirm the relevence of your content through other means including your sites page structure and through the use of breadcrumbs. Just like Google can understand that a page that mentions automobiles might be relevent for the search term cars it will also know that if a page about cars is directly below a page about road vehicles in a sites hierachy then it is even more relevent to the keyword cars. That page about road vehicles directly above it is re-enforcing the subject matter on that page. This is partly where the siloing that I talked about in part 3 comes in.
Similarly using breadcrumbs (An on page navigation aid to show a user where abouts in your sites hierachy they currently are) can also help to re-enforce the subject matter and relevence of a page.
How on-page factors compare to off-page factors
I know that a lot of people say this - you must get your onpage SEO spot on otherwise no amount of backlinks will help you. However I think this is one of those phrases (Like work harder not smarter) that has become a buzz phrase that people use without really thinking about it.
The reality is that offpage factors still hold way more weight than onpage factors and especially when you think about how Google are looking more at semantic analysis it is easy to see that onpage SEO (As we know it) is becoming less important.
From my personal experience I would say that traditional onpage factors are used more by Google when there are no other factors available - ie if there are no strong indicators from off page factors. But when there are strong offpage factors giving relevence to a website then onpage factors (Like exact match keyword density and title optimization) become less important.
I saw this recently in a site that I am working on where I had fully optimized one particular page on the site and found that once I started building backlinks to the site as a whole another un-optimized page went above the one I had optimized in the results.
This tells me that a) offpage factors hold more weight and b) Google doesnt neccesarily listen to blatent onpage optimization factors but rather uses semantic analysis to determin a pages relevence to any particular keyword.
Thats it for this part, hope this has given some beginners the info they need to optimize their websites and webpages and also I hope this will inspire some discussions from more experienced members here as well.