The Free Converter (Node.js SDK & CLI)

The official Node.js client and CLI toolkit for The Free Converter — a comprehensive suite of 160+ privacy-focused file conversion tools, financial calculators, SEO analyzers, and text utilities.

Online Web Platform & Tool Hubs

Access full-featured, browser-based online tools with zero software installation required:

• 📄 PDF & Document Converters — Convert PDF to Word, Excel, JPG, PNG, EPUB, CSV, RTF, TXT, and manage PDF security, merging, splitting, compression, and watermarking.
• 🎵 Audio & Video Converters — Transcode MP3, WAV, AAC, FLAC, OGG, M4A, OPUS, MP4, and WEBM with high-fidelity acoustic preservation.
• 🖼️ Image & Next-Gen Graphic Converters — Convert WEBP, AVIF, HEIC, PNG, JPG, SVG, and RAW camera DNG formats with optimized lossless and lossy compression.
• 🔍 SEO & Webmaster Tools — Audit broken links, verify dofollow/nofollow link equity, validate XML sitemaps, extract sitemap URLs, and monitor domain age.
• 💰 Financial & Tax Calculators — Calculate mortgage amortization, mortgage overpayment interest savings, crypto capital gains (FIFO/LIFO/HIFO), compound interest, VAT addition/extraction, and GST breakdowns.
• ✍️ Text & Markup Utilities — Format & validate JSON, convert text to JSON arrays, deduplicate large email/URL lists, count words/reading times, and convert Markdown to clean HTML.

Installation

Install via npm:

npm install thefreeconverter

Or install globally for CLI usage:

npm install -g thefreeconverter

Node.js Quickstart

1. Financial & Tax Calculations

const {
  calculatePercentageChange,
  calculateCompoundInterest,
  calculateMortgagePayment,
  calculateVat,
  calculateGst,
  calculateEffectiveInterestRate
} = require('thefreeconverter');

// Calculate percentage increase
const change = calculatePercentageChange(50, 65);
console.log(`Percentage Change: ${change}%`); // +30.0%

// Calculate compound interest growth with monthly deposits
const ci = calculateCompoundInterest({
  principal: 10000,
  annualRatePercent: 7.5,
  years: 10,
  compoundingFrequency: 12,
  monthlyContribution: 500
});
console.log(`Future Balance: $${ci.futureValue.toLocaleString()}`);
console.log(`Total Interest Earned: $${ci.totalInterest.toLocaleString()}`);

// Calculate monthly mortgage amortization (P&I)
const mortgage = calculateMortgagePayment({
  principal: 350000,
  annualRatePercent: 6.5,
  termYears: 30
});
console.log(`Monthly Payment: $${mortgage.monthlyPayment}`);
console.log(`Total Lifetime Interest: $${mortgage.totalInterest}`);

// Add or extract VAT / GST
const vat = calculateVat(120.0, 20.0, 'extract');
console.log(`Net Price: $${vat.netAmount}, VAT Extracted: $${vat.vatAmount}`);

2. Text & Data Formatting

const {
  formatJsonString,
  deduplicateLines,
  countTextMetrics
} = require('thefreeconverter');

// Prettify and validate raw JSON
const rawJson = '{"name":"TheFreeConverter","tools":166,"features":["pdf","audio","finance"]}';
const prettyJson = formatJsonString(rawJson, { indent: 2 });
console.log(prettyJson);

// Fast line deduplication
const rawList = ["[email protected]", "[email protected]", "[email protected]", "[email protected]"];
const uniqueLines = deduplicateLines(rawList, { caseSensitive: false });
console.log('Unique entries:', uniqueLines);

// Real-time text & readability analysis
const metrics = countTextMetrics("The quick brown fox jumps over the lazy dog.");
console.log(`Words: ${metrics.wordCount}, Characters: ${metrics.charCount}, Reading Time: ${metrics.readingTimeSeconds}s`);

Command Line Interface (CLI)

The package installs the thefreeconverter (or alias tfc) CLI command:

# Calculate percentage difference
tfc percentage --initial 50 --final 75

# Calculate monthly mortgage payments
tfc mortgage --principal 400000 --rate 6.5 --years 30

# Calculate compound interest
tfc compound --principal 5000 --rate 8 --years 20 --monthly 250

# Prettify a JSON file
tfc format-json --input config.min.json --output config.json --indent 2

Security & Privacy Commitment

At The Free Converter, we believe your data should remain yours:

• Client calculations run locally in memory.
• Web conversions execute in isolated, secure sandboxes with automatic purging.
• We never store, catalog, or inspect your uploaded files.

License

This project is licensed under the MIT License — see the LICENSE file for details.