readability-score

Zero-dependency readability analysis for JavaScript. Supports 5 algorithms, works on plain text strings and DOM elements.

Algorithms

| Algorithm | Best For | Output | |---|---|---| | Flesch Reading Ease | General content | 0–100 (higher = easier) | | Flesch-Kincaid Grade | Educational materials | US Grade level | | Gunning Fog | Business/journalism | Years of education | | SMOG Index | Healthcare content | US Grade level | | Coleman-Liau | Digital/web content | US Grade level |

Installation

npm install readability-score

Usage

Analyze text

import { ReadabilityAnalyzer } from 'readability-score';

const analyzer = new ReadabilityAnalyzer();
const result = analyzer.analyze("Your text goes here...");

console.log(result.consensus);
// { averageScore: 8.2, label: 'Standard', audience: 'High school', summary: '...' }

console.log(result.scores.fleschEase);
// { algorithm: 'Flesch Reading Ease', score: 65.2, gradeLevel: '8th-9th grade', label: 'Standard', audience: 'Age 13-15', interpretation: '...' }

Analyze a DOM element

const result = analyzer.analyzeDOM('#article');
const result = analyzer.analyzeDOM(document.querySelector('main'));

Run specific algorithms only

const result = analyzer.analyze(text, ['fleschEase', 'gunningFog']);

Quick single-score methods

analyzer.fleschEase(text)     // → { score, label, gradeLevel, audience, interpretation }
analyzer.fleschKincaid(text)
analyzer.gunningFog(text)
analyzer.smog(text)
analyzer.colemanLiau(text)

Individual algorithm imports (tree-shakeable)

import { fleschReadingEase, parseText } from 'readability-score';

const metrics = parseText("Your text here...");
const result  = fleschReadingEase(metrics);

Result Structure

{
  metrics: {
    wordCount: 120,
    sentenceCount: 8,
    syllableCount: 180,
    complexWordCount: 12,
    characterCount: 520,
    avgWordsPerSentence: 15,
    avgSyllablesPerWord: 1.5,
  },
  scores: {
    fleschEase:    { algorithm, score, gradeLevel, label, audience, interpretation },
    fleschKincaid: { ... },
    gunningFog:    { ... },
    smog:          { ... },
    colemanLiau:   { ... },
  },
  consensus: {
    averageScore: 9.1,
    label: 'Standard',
    audience: 'High school',
    summary: 'Overall: Standard (avg score 9.1). Best suited for High school.',
  }
}

Labels

| Label | Audience | |---|---| | Very Easy | Elementary school / Age 10 and under | | Easy | Middle school / Age 11-12 | | Fairly Easy | Age 12-13 | | Standard | High school / Age 13-15 | | Fairly Difficult | Age 15-17 | | Difficult | College level | | Very Difficult | Post-graduate |

License

MIT