Think the danger of running into a tribe of savage cannibals is limited to the sci-fi fantasy worlds of Soylent Green, The Walking Dead and Game of Thrones? The truth is, you may unwittingly have anthropophagists lurking in your SEO strategy, hungrily consuming all your content optimization efforts.

If you have a website, chances are you have pages of content that are competing with each other for the same main keywords. Search engines like Google will almost certainly display only one of those pages for a given keyword query on its results page, so the decision as to which page has the highest relevance is left to the search engine. The competing pages within your site are fighting for, or cannibalizing the keyword, resulting in an unfortunate end for one or all your overlapping pages.

Take control of your search optimization strategy out of the search engines’ hands with a strong canonical SEO strategy. Canonicalization is an oft-used phrase in search optimization and website development, but in this context, the term is aimed at a page that owns a given keyword phrase or theme, and the keywords themselves. A canonical SEO strategy clearly assigns target keyword(s) (and closely related derivations) to a single canonical page and sends clear signals to search engines and, perhaps more importantly, your human visitors, as to which page is the authority and the place they’re most likely to find the content for which they’re searching.

Example of duplicate content due to URL parameters, causing canonical keyword cannibalization
If your site uses URL parameters, make sure the rel=canonical tag points to the original or best source of the content.

For example, if you have an E-commerce website that sells (cannibal) hunting gear, it’s important that you have only one page that owns “hunting vest” as well as very similar phrases and search parameters like “hunting vest size large” and “men’s hunting vest.” If you have multiple pages targeting each one of those close derivations, or every page of your site features “Hunting Vests” in the title tag, you’ve got cannibals in your midst! Here’s how to fight them off:

Create a Canonical Keyword Map

Start by getting a clear bird’s-eye view of all your website’s indexed content and the page titles, meta descriptions, headline tags, on-page content and internal link anchors. Screaming Frog is a great tool for gathering this information with just a few clicks. Export a list of all your HTML page URLs that are capable of being indexed (filter out pages with a 3xx, 4xx or 5xx server status, and pages that already have a noindex meta robots tag.)

Next, create a spreadsheet workbook and paste the raw exported Screaming Frog report into the first tab. Add a column for Canonical Keywords, which you’ll fill in later. Right away, start highlighting page URLs for which there is a glaring overlap in keywords found in the Page Title and H1, two obvious sources of which keywords the pages are targeting. These pages are the best place to start identifying areas of cannibalization, crafting your canonical strategy and creating some space between overlapping keywords.

Third, do some keyword research, using your favorite keyword discovery methods and create some more worksheet tabs to hold your findings. I recommend you use a site analytics tool like Google Analytics to find what organic search keywords are already driving traffic in general, as well as what landing pages are being found at the end of those keyword click-throughs. These two reports will give you clear insight into:

a) what keywords you’ll want to keep in your canonical strategy
b) which keywords the search engines already think should be mapped to each landing page, and whether your strategy should keep those decisions intact or try to right the ship.

Your keyword discovery process should also take into consideration which keywords your site is already ranking 1 – 20 in your favorite search engine. Furthermore, you might want to make note of the keywords for which your competitors are ranking on the first two search engine results pages (SERPs) and your website is not. SEMRush is a great tool to accomplish both of these tasks.

In the final keyword discovery step, use a tool like the Google Adwords Keyword Planner, MOZ Pro Keyword Difficulty Tool or Wordtracker to find the search volume and competition/difficulty for your Already Referring, Already Ranking and Competitor Opportunity keywords as well as finding new, unexplored keyword suggestions you can use to differentiate your cannibalized content in the next step.

Next, go to your Canonical Keywords column and start making some decisions about what keyword phrases each page should naturally own. Use what you learned from the site analytics reports about what keywords are currently mapped to each landing page. Using the hunting gear example, if you have a page targeting Men’s Hunting Clothing and another page targeting Men’s Hunting Wear, you’ll need to address those pages with either unique keywords or a canonical directive.

Decision Time

Now that you’ve identified which pages are cannibalizing their keyword phrases, it’s decision time:

If two pages have duplicate or near duplicate content – including category and tag pages and pages with URL parameters – you need to decide which of the two is the optimal or canonical version (e.g. ranks higher when you do an advanced search command – shared keyword phrase; has a bigger/better backlink profile and Page Authority; has more internal links; has a higher conversion rate, etc.) Use a 301 redirect from the non-optimal to the canonical version, or add a meta robots NOINDEX,FOLLOW tag and a canonical rel= tag pointing to the canonical version in the non-optimal page’s header.

If two or more pages are targeting a main keyword phrase like “Hunting Vest,” use your keyword discovery and intuitive sense to differentiate the two pages based on their content. Perhaps one page actually features a Mesh Back Hunting Vest while the other features a Cotton Field Hunting Vest. These are two different pages of content that pass this simple gut check: If a human user searched “mesh back hunting vest,” am I doing everything I can to make sure they land on the Mesh Back Hunting Vest page instead of the Hunting Vests category page or the home page?

Example of Keyword Cannibalization in Page Titles
Highlight page titles that have a significant degree of keyword overlap, or cannibalization

Use the canonical keywords you’ve mapped to each page to rewrite and shore up your page titles, descriptions, H1 and H2 tags. Take it a step further by ensuring that your internal links point to the canonical (optimal) versions upon which you’ve decided, using anchor text that supports the canonical strategy for that page.

Save Your Skin

A strong canonical SEO strategy is the best defense against keyword cannibalization. It gives you control over which pages should rank for given keyword queries; fends off unintentional duplicate content issues; helps increase click-through rates and lower bounce rates; clears the way for you to create new, deeper content that your users will find relevant and engaging versus replicated and thin; and offers confident insight into what organic search keywords are resulting in which landing pages, a big benefit in today’s “not provided” and “not set” era of site analytics.

Do you have a canonical SEO strategy? How do you start your keyword mapping process?