Best Keyword Density Checkers (& What Matters More in 2026)

Here at AIOSEO, we're often asked: “What's the best keyword density checker?”

And I understand why. For years, the SEO world was obsessed with hitting a specific density percentage to rank.

But as SEO professionals who live and breathe this every day, our advice is now very different: stop chasing a perfect density score. Google is far more sophisticated now. It cares more about overall topical relevance and natural language than simple keyword repetition.

So, in this guide, we'll do two things:

1. First, we'll cover the best keyword density checkers for a quick analysis (because it's still good to know). 
2. More importantly, I'll show you the modern approach we use ourselves—focusing on holistic on-page SEO that actually gets results today.

This way, you’ll be able to check keyword density and optimize your content more effectively.

What Is Keyword Density?

Keyword density is the percentage of times a specific keyword or phrase appears in your text, compared to the total number of words.

Here's the formula:

Keyword Density = (Number of times keyword appears / Total number of words) x 100

For example, you've written a 1000-word blog post, and the focus keyword “best keyword density checker” appears 15 times. Here's how you'd calculate the keyword density:

(15 / 1000) x 100 = 1.5%

So, your post's keyword density for “best keyword density checker” is 1.5%.

Does Keyword Density Still Matter Today?

In the early days of search engines, keyword density was a big deal.

The more you used a keyword, the more “relevant” Google thought your page was. This led to an era of “keyword stuffing,” where people would cram their keywords into pages unnaturally just to hit a specific percentage.

Today, those days are gone.

Based on my 6+ years in SEO, I can tell you that modern search engines like Google are far more interested in topical authority and natural language.

They use sophisticated systems to understand what your page is about as a whole, not just how many times you repeat a single phrase.

That's why at AIOSEO, our TruSEO Score doesn't just give you a simple density score. Instead, our on-page analysis looks at the bigger picture to give you a more holistic and actionable checklist, focusing on things like:

• Keyphrase placement: Is your main keyword in important places like your SEO title, introduction, and subheadings?
• Related keywords: Are you including semantically related terms (LSI keywords) to build topical relevance?
• Readability: Is your content easy for users to read and understand?

You get your score and SEO feedback directly in the WordPress editor as an actionable checklist:

Ultimately, the best keyword density checkers will allow help you understand your keyword usage and focus on the bigger picture.

Why Should I Still Check Keyword Density?

If search engines are more interested in understanding the main point of your article, surely you can just forget keyword density checker tools altogether, right?

Wrong.

There are still strong arguments for seeing how often you use your keyword in a text. Here are some of the biggest benefits of using keyword density checker tools:

Benefit 1: Helps Search Engines Understand Your Content 

Search engines like Google use keywords to determine what your page is about. By including relevant keywords, you're essentially telling them, “Hey, this page is about this topic!”

And, as we've seen, this is the main goal of modern SEO.

Benefit 2: Avoids Keyword Stuffing

Back in the day, some people tried to manipulate search engine rankinggs by cramming their content with keywords.

This black hat SEO tactic is known as keyword stuffing, and today, it's a big no-no. Modern search engines are smart enough to recognize this and will penalize you for it.

You can avoid this issue by using related keywords and synonyms.

Benefit 3: Balances Optimization With User Experience

The goal is to use keywords naturally so your content doesn’t sound awkward or repetitive. You want to write for people, not just search engines.

Keyword density helps you optimize your content for search engines while creating a positive experience for your readers.

Why Should You Trust This Review

As someone who writes and optimizes content daily, I know firsthand that accurate keyword density checking is essential. That's why I put each tool through real-world testing using my own content and websites.

My Testing Process

I’ve tested each keyword density checker using three different types of content:

• A 2,000-word blog post about WordPress plugins
• A 500-word product description
• A long-form guide about SEO (5,000+ words)

For each piece of content, I analyzed how well the tools performed in these key areas:

Accuracy & Reliability

I compared the keyword density results across multiple tools to verify accuracy. I also checked if the tools could identify variations of keywords and related terms. This helped me understand which tools provide the most reliable data.

Ease of Use

Having tested these tools with both beginners and experienced content creators, I focused on:

• How quickly you can get results
• Whether the interface is clear and intuitive
• If the tool provides helpful suggestions
• How easy it is to understand the reports

Advanced Features

I looked beyond basic keyword density checking to see what extra value each tool offers:

• Multiple keyword tracking
• Natural language processing capabilities
• Content optimization suggestions
• Integration with other SEO tools

Now, let's get into the keyword density checker tools.

Best Keyword Density Checkers At a Glance

If you're short on time, this table compares all the tools in our lineup:

Tool Name	What it Measures	Best For	Type
All in One SEO (AIOSEO)	Holistic on-page SEO (beyond density)	WordPress users wanting a complete, modern SEO analysis inside their editor	Free version available, paid plans start at $49.50/mo
WPBeginner Keyword Density Checker	Basic keyword density by URL or text	A quick, free, and simple density check without any complex setup	Free
Semrush	Keyword density, readability, SEO score	Marketers needing an all-in-one toolkit for research, writing, and deep analysis	Starts at $119.95/mo
Yoast SEO	Keyword density & on-page SEO signals	WordPress users wanting a standard keyword density feature	Free version available, paid plans start at $99/yr
Small SEO Tools	1, 2, & 3-word keyword density	Getting a quick, no-frills density percentage for a piece of text	Free
Rank Math	Keyword density & on-page SEO score	WordPress users who want a feature-rich SEO plugin with a density checker.	Starts at $6.99/mo
SEO Review Tools	Keyword density & frequency	A free, detailed analysis of keyword frequency and distribution within your text.	Free

Best Keyword Density Checkers (Free & Paid)

Now that you've seen an overview of our top picks, let’s take a deep dive into the best keyword density checkers.

1. All In One SEO (AIOSEO)

AIOSEO is the best keyword density checker for WordPress users. It’s a powerful yet easy-to-use SEO plugin that boasts over 3 million active users.

Many smart business owners and bloggers use AIOSEO to boost their search engine rankings and drive qualified traffic to their sites. This is because the plugin has features designed specifically for WordPress SEO, letting you optimize your posts and pages for greater visibility on search engines.

Regarding keyword density, AIOSEO makes checking this element easy inside your WordPress editor.

To check keyword density, simply access the AIOSEO menu on any WordPress page.

Then, click the General tab and add your target keyword to the Focus Keyphrase section. AIOSEO will then analyze your page, checking for the keyword's presence in some of the most important areas of your post.

You'll see what's working well and what needs improvement. 

At the bottom of the Focus Keyphrase section, you'll find your keyword density report, indicating if you need to add more instances of your keyword for better SEO.

I love that AIOSEO gives me a percentage AND the number of times my keyword appears in the text. This helps speed up the process of adding more keywords or removing them, depending on the recommendation.

To help reduce keyword stuffing, you can get LSI keywords by clicking the Get Additional Keyphrases button. Currently, this only works if you’ve connected Semrush to your AIOSEO account.

This is a great way for beginners to improve their content optimizations. Instead of guessing about keyword placement, you can get precise data showing exactly where you need to make changes.

Ultimately, I've found AIOSEO to be the most reliable and user-friendly keyword density checker for WordPress. Its accurate, easy to use, and has comprehensive features that can increase your site's overall visibility in search engine results pages (SERPs).

Pricing: Paid plans start at $49.60/month. Free version also available.

2. ​​WPBeginner Keyword Density Checker

WPBeginner’s Keyword Density Checker is the best standalone tool for checking your keyword density. One thing I like about it is that it’s super easy to use. You can either enter a URL or paste your text, and the tool will give you several lists organized by the number of words in the keyword.

This makes it easy to locate your target keyword and get an idea about your overall keyword usage.

I also like that you can use this keyword density checker to analyze your competitors’ content to see which keywords they’re optimizing for.

This is great for beginners who are still navigating keyword density and learning how to leverage it for SEO.

Pricing: Free.

3. Semrush

Semrush is a go-to digital marketing tool for millions of marketers. While it's famous for keyword research and competitor analysis, it also boasts a powerful keyword density checker. This can be found under the On Page SEO Checker tab. 

What impressed me most during testing was how Semrush analyzes your content against top-ranking competitors. 

This tells you how often your rivals are using your target keyword in their content, titles, headings, and descriptions. 

You can see your own keyword density compared to their average, and even how many times each word in a longer keyword phrase appears. It even uses something called Term Frequency–Inverse Document Frequency (TF-IDF) to show how important your keyword is to the overall topic of the page, letting you compare your score to your rivals.

One of the letdowns with Semrush is that using the keyword density checker is a bit complicated. The reports can also be overwhelming for beginners.

Pricing: Semrush’s paid plans start at $119.95/month.

4. Yoast SEO

Yoast SEO is another WordPress plugin that has a keyword density checker. I particularly appreciate how it makes keyword density checking accessible to WordPress users of all skill levels.

Yoast’s keyword density checker works in real time as you write your content in the WordPress editor. You get immediate feedback on keyword usage without switching between different tools or browsers.

While basic, the tool is helpful in ensuring you don’t overoptimize your content.

Pricing: $99/year. Free plan available.

5. Small SEO Tools Keyword Density Checker

Small SEO Tools’ Keyword Density Checker works in the same way as WPBeginner in that it has the same input capabilities (URL or text). However, you get additional insights about your content optimizations. One of the most notable is how it also shows a list of your top keywords in the report.

I also like how Small SEO Tools highlights when you’ve included a specific keyword in an important section of your content, such as the title, description, or header tag. 

Small SEO Tools really shines compared to other keyword density checkers because of its unique visual elements. However, unlike keyword density checkers like AIOSEO, you’ll have to jump between tabs to run your checks.

Pricing: Free.

6. Rank Math

Rank Math is a popular WordPress SEO plugin that stands out for its built-in content optimization features, including a robust keyword density checker. 

As you write or edit a post, Rank Math analyzes your use of both primary and secondary focus keywords, providing real-time feedback on your keyword density directly within the WordPress editor. The tool recommends keeping your keyword density between 1% and 1.5% for optimal results, helping you avoid both under- and over-optimization.

Rank Math’s interface is fully integrated with both the classic and block editors in WordPress. You can view your SEO score and all optimization suggestions in one place, making it easy to adjust your content as you go. 

Pricing: Paid plans start at $6.99/month.

7. SEO Review Tools Keyword Density Checker

SEO Review Tools Keyword Density Checker works much the same way as WPBeginner’s Keyword Density Checker. It generates keyword lists by word count. And like Small SEO Tools, it also includes some visual aids to bring your attention to specific elements. 

One element I liked about this tool is that it gives you more options to analyze the keywords it checks. For example, besides getting keyword density, you can also:

• Conduct keyword research.
• Get featured snippet suggestions.
• Check keyword volume.

You can also get the Chrome extension of the tool to reduce jumping between browser tabs when checking keyword density.

Pricing: Free.

Best Keyword Density Checker (Our #1 Pick)

Our top pick for the best keyword density checker for WordPress is All In One SEO (AIOSEO). This powerful plugin gives reliable data on keyword usage and easy-to-follow recommendations on how to improve your content.

I also love that it's a one-stop shop for most SEO needs. Whether you're trying to improve your site speed or add schema markup without code, AIOSEO makes it easy.

Beyond Density: The On-Page SEO Checklist We Use

I promised to show you the modern approach our team at AIOSEO uses to rank content. It’s a simple, repeatable process that moves beyond a single keyword density score and focuses on what search engines actually care about.

Here's our 3-step checklist for optimizing every piece of content.

Step 1: Strategic Keyphrase Placement

Instead of worrying about how many times you've used a keyword, we focus on placing it in a few high-impact locations where it matters most to both users and search engines.

For every article, we ensure our main keyphrase appears in the following areas:

• SEO title and meta description
• First paragraph of the introduction
• H2 and H3 subheadings
• Body copy (naturally, where it makes sense)
• Conclusion

This is the very first thing our TruSEO analysis checks for because it sends the clearest possible signal to Google about your content's main topic.

Step 2: Build Topical Authority with Related Keywords

Modern SEO is about proving your expertise on a topic as a whole. The best way to do this is by including semantically related keywords and concepts (often called LSI keywords) throughout your text.

For example, in this article about “keyword density checkers,” we've also included terms like “topical relevance,” “on-page SEO,” “natural language,” and “TruSEO score.” This shows Google that we have a deep understanding of the entire subject.

Step 3: Optimize for Readability and User Signals

Finally, we optimize for the most important ranking factor of all: the reader. If users find your content hard to read, they'll leave, sending negative signals to Google.

We focus on:

• Clear and concise sentences
• Breaking up long paragraphs
• Using internal and external links to provide more context and value

This is why the Readability analysis inside All in One SEO is so crucial. It gives you direct, actionable feedback to improve the user experience, which in turn leads to better rankings.

This 3-step checklist is a more reliable and sustainable way to rank than chasing an single metric or score. It's talso he exact methodology we've built into the AIOSEO plugin to help you do the same.

Next Steps: Your Modern SEO Path

While it can be tempting to focus on a single keyword density metric, the biggest takeaway I can offer you is this: good SEO is about the big picture. Don't get too distracted by individual SEO scores. Instead, think of your audience and create content they want to read.

So, what's your next step?

Here are some tips for shifting your focus to a more modern and effective workflow:

1. Write for your readers first. Create helpful, engaging content that answers their questions.
2. Place your keyphrase naturally in a few important spots like your title, meta description, introduction, and body copy.
3. Use a modern keyword density checker tool to guide your keyword usage and overall on-page SEO.

I hope this article helped you discover the best keyword density checker tools and find the right one for your needs. You may also want to check out other articles on our blog, like our WordPress SEO cheat sheet for beginners and our list of the best content optimization tools for SEO.

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FAQs About Keyword Density Checker Tools

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