Keyword Density Is the Worst Metric for SEO
The process of optimizing content for search — literally, SEO — is not formulaic. You can’t easily or effectively automate it, and what passes for “optimal” is constantly changing.
Yet the notion that keyword density is critical to SEO success never seems to go out of fashion. The moment you bring up keywords as an important element of SEO, people naturally want to know: “how many?”
This question is asked as though all it takes to rank well for a topic is repeating a keyword some predetermined number of times per page. That’s what measuring keyword density tells you: how many times you’ve repeated yourself. It isn’t a strategy, and it isn’t optimization.
There was a time when keyword density was central to search algorithms, but for over a decade, that hasn’t been the case. Technology and searchers both have moved beyond that system. Yet the idea of keyword density impacting SEO persists, probably because it is attractively simple.
Never forget: SEO can be simple, but it isn’t that simple. If optimization were that easy, everyone would do it — and not everyone who wants to rank for keywords proves capable.
To understand why keyword density is a distraction from true SEO, you first must understand the absolute basics of keywords themselves.
There are endless editorials and much confusion about what keywords are, how they work, and what we do with them to accomplish SEO goals.
Need help finding your most lucrative keywords? Download this free guide to unlock your data and start building easy-to-use keyword reports.
In principle, it is all really quite simple. Keywords represent popular topics. The more people search for information about a topic, the higher the search volume for the associated keywords. The most basic keyword associated with a topic is called a head term.
Head Term example: “president”
When you add modifiers or additional words to a head term, you get a keyword phrase. Keyword phrases use different modifiers to make topics more specific or complex. They make it clearer what people are actually searching for.
Keyword Phrase example: “current us president”
Finally, long-tail keyword phrases most commonly reflect how people use natural language and sometimes complete sentences to ask specific, direct questions.
These are great for optimizing titles, because it shows readers that the content on the page corresponds to the actual question they asked or topic they are researching.
Long-Tail Keyword Phrase example: “who is the current us president”
Keyword density is a number, usually a percentage, measuring how much of a page is made up of a head term, keyword phrase, or long-tail keyword phrase.
How To Calculate Keyword Density
Calculating keyword density is really just a matter of counting, although normally it is presented as a percentage. There are a number of tools that do it for you, but the manual process is almost as easy. Step one is:
- Don’t do it. It’s a trap!
Seriously, knowing this number will rarely prove to be anything more than a distraction; at worst, using it will undermine your actual ability to optimize content. At best, it makes for useless trivia.
However, if you must, the equation is as follows:
( Keyword Appearances / Total Word Count ) x 100
The elements of this formula include:
- Keyword Appearances — The number of times your target word or phrase appears on the page.
- Total Word Count — The number of words on the page.
- And multiplying the number by 100 to convert it into a percentage.
Here is an example:
(10 keyword appearances / 1,000 words ) x 100 = (.01) x 100 = 1%
If you increase the number of words on the page, your keyword density tends to go down. If you repeat your target keyword or phrase more, keyword density tends to go up. It is not difficult to manipulate, and it is not difficult to ascertain, but neither will do much to improve your SEO.
Keyword Density Checkers and Tools
Again, don’t use them. They aren’t helping you.
There are many tools, and they are user-friendly and well-designed and easy to use, but they are a distraction from what matters. Possibly the most popular example is Yoast, which is by far the most common SEO plugin used on WordPress sites. Yoast has its merits and its applications, but I cannot emphasize enough how measuring keyword density is not one of them.
This is one of the important concepts behind keyword density, and what makes it a problematic metric. If you start mentioning a keyword or phrase more than is natural, contextual, or relevant, it looks and sounds artificial. This is keyword stuffing — literally, stuffing your target term or phrase into a page to increase the density, but without improving the quality of the content or serving readers in any meaningful way.
There was a time, in the early days of Google and web search, when keyword density was central to ranking. Site owners and web developers realized they could rank for virtually anything, simply by repeating the target term ad nauseum — albeit disguised, by making the text color match the background.
To the average reader, it didn’t look like keyword stuffing at all, but search engines would crawl and record all these hidden keywords and phrases, and associate them with the content of the page. Presto! Artificially ranking without truly optimizing content. This is one of the classic black hat SEO strategies.
Even though this egregious form of keyword stuffing is more or less extinct and ineffective, keyword stuffing remains prevalent, even if by accident.
Well-intentioned site owners and content creators routinely wind up keyword stuffing out of an effort to improve keyword density. This is partly why keyword density is a distraction, but potentially a complete misdirection that ultimately hurts, rather than helping, your SEO goals.
The point of keyword research is to discover what topics searchers want to learn about, and what language they use to find that information. Beyond that, it is a matter of strategy to determine how exactly to use those keywords to create content, inform web development, or set and achieve SEO goals.
Having a spreadsheet full of keywords and search volume does nothing to convey what makes a good result; it doesn’t tell you who the people using the keywords are; it doesn’t tell you what searchers actually want, or if the words they are using accurately reflect the intent behind them.
Many keyword research tools will present information on keyword density alongside more useful metrics like monthly search volume.
Don’t be fooled: just as it is easy for you to calculate keyword density on a given page, it is easy for these tools to calculate average keyword density across several pages. They can even generate fanciful but irrelevant statistics like Minimum Keyword Density, or the lowest keyword density in content that ranks on page one of the SERPs. It may sound impressive, but it is no more helpful to your SEO strategy than aiming for maximum keyword density.
Ultimately, keyword research is just the start of a strategy, not the strategy itself. Real SEO is taking thoughtful, nuanced insights from keyword research to inform content creation.
People Search for Answers, Not Questions
The problem with repeating the titular question within the answer 10 times is that no good answer does that. The question is the question, the answer is the answer.
People don't use keywords in search to be reminded of what they searched for — they search for answers. Keywords help them find answers, but they shouldn't be the main ingredient in the answer.
Imagine asking your doctor if you had cancer. If your doctor responded by mentioning cancer 20 times, you might be concerned, even if the context wasn’t bad news. If your doctor just said, “No, you don’t have cancer” the message would be much clearer, without unnecessary repetition. The same logic applies to SEO. Google strives to understand intent, and keywords are only one part of that.
Anyone who passed 7th grade English knows how to pad an essay with rambling, meaningless, stalling-for-time verbosity without saying anything. Buffing your keyword density achieves essentially the same thing: more words without necessarily more detail or better information.
Good Content Satisfies Searcher Intent
If you want to truly optimize for search, then you need to make sure your content speaks to what people want, not just the words they use. That means you need to understand intent, not just parrot words and phrases at intervals.
There is often a gap between what people search for, and what they actually want to know, learn, or discover with their search. Keywords reflect how people search, and they help describe what they think they are looking for. That doesn’t mean they are the best way to describe something, or the best way to articulate a good answer.
A search for “pizza near me” doesn’t mean someone smells pizza and wants to know which room it is in. Google understands this, and uses location-based filters to help these searchers identify nearby restaurants.
In other searches, this kind of distinction can be softer, more ambiguous, or subject to other details besides an IP address, but they still matter. It is easy to find and repeat keywords, but more challenging to unpack the journey of discovery searchers are on when they use a search engine.
Keyword Density Does Not Reflect Keyword Optimization
How you use keywords contextually, where you place them on a page, and how you use natural variations are all more important for SEO than pure density. If you’re going to focus on just one or two elements of on-page optimization, the best alternatives to keyword density are:
When they land on a SERP, people first see and click on title tags, but then they want information. So using your keywords in the title tag matters most of all to capture search traffic before you follow through with great content.
There isn’t a lot of opportunity to bolster density in title tags, so you’re better off writing a good, descriptive title that uses keywords while addressing searcher intent. That’s the single-most important ranking factor you can control.
After the title tag, headers are the next-most powerful meta elements you can optimize for keywords. The H1 — the main display title at the top of the page — needs to agree with the title tag, and describe the contents of the page as a whole. That still doesn’t mean you should cram it full of keywords to maximize density. Again, just be descriptive, tell people what the page is about, and set the right expectations.
When it comes to subheaders — H2s, H3s, etc — it can make sense to use keywords and phrases, but it can also make sense to ignore keywords and focus on creating a good, detailed answer.
For example, if the topic of a page is “How to Tie a Bowtie” you don’t need to repeat the word “bowtie” in every header. It makes sense to match this query in the title tag and H1, but after someone has gotten to your page, they want instructions.
Readers, and bots, are both going to understand that each subheader describes a step in the process, and won’t be bothered that “bowtie” or “tie” or “how to” aren’t being echoed over and over. Keyword density may come out low, but the satisfaction of searcher intent should be high — that is optimized content.
There are many, many other HTML elements and meta tags you can leverage strategically to emphasize your keywords, but the point is that bots aren’t stupid, and they aren’t just counting words on a page. They read things in a certain order, and assign more weight to certain elements.
Title tags, H1s, subheaders, alt text, anchor text for inbound links — these all matter, and making them repetitive isn’t using them correctly. Be descriptive, focus on searcher intent, and try to write quality content, and you’ll be better off.
Google Cares About Both Quantity and Quality
When we talk about Google in the context of search, what we really mean is the Google algorithm — the automatic system that crawls the web, indexes pages, and interprets content to provide search results. You don’t need a programming background to understand that this algorithm is non-linear.
Different features, including keyword usage, are weighted differently to determine purpose, relevance, and quality. If you are taking medication, you can’t simply take extra to get better or faster results. Similarly, you can’t just increase keyword density to trick Google’s algorithm into treating your content as more relevant or higher quality.
The full inner workings of the algorithm aren’t public, but Google representatives routinely make comments, publish blogs, and tweet about how search works. Perhaps the most famous public-facing document related to how Google defines “quality” in search results is a tome known as the Search Quality Evaluator Guidelines. This is how Google solicits real human contractors to manually review SERPs and provide constructive feedback.
Throughout these guidelines, Google makes constant references to content quality and searcher intent/satisfaction. It also speaks very negatively about keyword-stuffing.
At no point do they mention keyword density. If you decide keyword density is essential to your SEO, then you are deciding that you know better than Google what makes a good result. Checking the scoreboard, I’d say Google has the advantage in knowing which SERPs keep people coming back.
There Is No Formula for Optimization
Everyone wants a shortcut — and nobody more so than professional SEOs.
A single, simple calculation to tell you how well you’ve optimized for a target keyword would be a wonderful tool. But real optimization is work.
Research, practice, thought, revision, and repetition. Don’t hang your strategy or your efforts on a single number — especially not when that number is keyword density.