.seo-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 8px;
background-color: #f9f9f9;
}
.seo-calculator-container h2 {
color: #333;
text-align: center;
margin-bottom: 25px;
}
.form-group {
margin-bottom: 20px;
}
.form-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #555;
}
.form-group input[type="text"],
.form-group textarea {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
font-size: 16px;
}
.form-group textarea {
height: 200px;
resize: vertical;
}
.calc-button {
width: 100%;
padding: 15px;
background-color: #0073aa;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s ease;
}
.calc-button:hover {
background-color: #005177;
}
#densityResult {
margin-top: 25px;
padding: 20px;
background-color: #fff;
border: 1px solid #d0d0d0;
border-radius: 4px;
display: none;
}
.result-metric {
font-size: 24px;
font-weight: bold;
color: #0073aa;
text-align: center;
display: block;
margin-bottom: 10px;
}
.result-details {
text-align: center;
font-size: 16px;
color: #666;
margin-bottom: 15px;
}
.density-analysis {
padding: 15px;
border-radius: 4px;
color: #fff;
text-align: center;
font-weight: bold;
}
.analysis-low { background-color: #f0ad4e; }
.analysis-good { background-color: #5cb85c; }
.analysis-high { background-color: #d9534f; }
.article-content {
margin-top: 40px;
line-height: 1.6;
color: #333;
}
.article-content h3 {
margin-top: 25px;
color: #222;
}
function calculateKeywordDensity() {
var textContent = document.getElementById('textContent').value;
var targetKeyword = document.getElementById('targetKeyword').value;
var resultDiv = document.getElementById('densityResult');
if (!textContent || !targetKeyword) {
resultDiv.style.display = "block";
resultDiv.innerHTML = "Please enter both content text and a target keyword.";
return;
}
// Normalize text: lowercase and remove excessive punctuation/spacing for accurate word counts
var normalizedText = textContent.toLowerCase().replace(/[^\w\s']|_/g, " ").replace(/\s+/g, " ").trim();
var normalizedKeyword = targetKeyword.toLowerCase().replace(/[^\w\s']|_/g, " ").replace(/\s+/g, " ").trim();
if (normalizedText === "" || normalizedKeyword === "") {
resultDiv.style.display = "block";
resultDiv.innerHTML = "Content must contain valid words.";
return;
}
// Calculate Total Word Count
var wordArray = normalizedText.split(' ');
var totalWords = wordArray.length;
// Calculate Keyword Frequency using Regex for accurate phrase matching with word boundaries
// Escaping regex special characters in the keyword if necessary
var escapedKeyword = normalizedKeyword.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
var regex = new RegExp("\\b" + escapedKeyword + "\\b", "gi");
var matches = normalizedText.match(regex);
var keywordCount = matches ? matches.length : 0;
// Calculate Density Percentage
var densityPercentage = 0;
if (totalWords > 0) {
densityPercentage = (keywordCount / totalWords) * 100;
}
// Determine analysis based on density
var analysisClass = "";
var analysisText = "";
if (densityPercentage = 0.5 && densityPercentage <= 2.5) {
analysisClass = "analysis-good";
analysisText = "Analysis: Optimal Density. Good job, this falls within a safe SEO range.";
} else {
analysisClass = "analysis-high";
analysisText = "Analysis: High Density. Beware of 'keyword stuffing'. Readability might be affected.";
}
// Output Results
resultDiv.style.display = "block";
resultDiv.innerHTML =
'
Understanding Keyword Density in Modern SEO
Keyword density is a foundational concept in On-Page SEO that refers to the percentage of times a specific target keyword or phrase appears compared to the total number of words on a webpage. While search engine algorithms have evolved significantly beyond simple keyword counting, ensuring your content clearly communicates its topic without crossing into spam territory remains crucial.
In the past, SEOs chased specific "golden ratios," sometimes sacrificing readability for math. Today, Google's algorithms (like BERT and SpamBrain) prioritize natural language, user intent, and topical depth over raw frequency. However, keyword density is still a useful metric for identifying two extremes: under-optimization (where search engines might not recognize your topic) and over-optimization (keyword stuffing).
How to Use This Calculator
This tool is designed to give you a quick snapshot of your content's optimization level for a specific term. To use it effectively:
- Copy the final draft of your article's body content (excluding navigation, sidebars, and footers).
- Paste it into the "Paste Your Content Here" text area.
- Enter the primary keyword phrase you are targeting (e.g., "best running shoes for flat feet") into the input field.
- Click "Calculate Density" to receive your analysis.
Interpreting Your Results: What is Good Density?
There is no universally perfect keyword density percentage. Different industries and types of content require different approaches. However, general SEO best practices suggest the following guidelines:
- Under 0.5% (Too Low): Search engines might struggle to identify this page as highly relevant for the search term. Look for opportunities to include the exact phrase naturally in headers or introductory paragraphs.
- 0.5% to 2.5% (Optimal Range): This is generally considered the "safe zone." The keyword appears frequently enough to establish relevance but not so often that it sounds robotic or unnatural to a human reader.
- Over 3% (Risk of Stuffing): While short texts might naturally have higher density, sustained high density in long-form content can trigger spam filters. Read your content aloud; if it sounds repetitive, use synonyms or related semantic terms instead of the exact match keyword.
Ultimately, write for humans first. Use this calculator as a final check to ensure you haven't accidentally overused a phrase, rather than a target to hit during drafting.