pyseoa-ts/dist/analyzer/keywordDensity.js

SEO analysis tools for the web, ported from pyseoa (Python) to TypeScript

import * as cheerio from 'cheerio';
export function analyzeKeywordDensity(html, keyword, thresholds = { low: 0.5, high: 2 }) {
    const $ = cheerio.load(html);
    // extract visible body text
    $("script, style, noscript").remove();
    const text = $("body").text();
    const words = text
        .toLowerCase()
        .replace(/[^0-9a-z\s]/g, "")
        .split(/\s+/)
        .filter(Boolean);
    const normalizeKeyword = keyword.toLowerCase();
    const count = words.filter(w => w === normalizeKeyword).length;
    const totalWords = words.length;
    const density = totalWords > 0 ? (count / totalWords) * 100 : 0;
    let score = 3;
    let message = "Keyword density is optimal.";
    if (density < thresholds.low) {
        score = 1;
        message = "Keyword density is too low.";
    }
    else if (density > thresholds.high) {
        score = 2;
        message = "Keyword density is too high.";
    }
    return {
        keyword: normalizeKeyword,
        count,
        totalWords,
        density: +density.toFixed(2),
        score,
        message,
    };
}