# ToolFesto

> Free, fast, and 100% client-side privacy-first web utilities, calculators, and converters. No accounts, no subscriptions, zero server file uploads, and full offline PWA compatibility.

## System Architecture & Security
- **100% Client-Side Execution**: All processing (PDF parsing, OCR, image compression, token counting, geometry scaling, cryptographic hashing) runs entirely in the user's browser via WebAssembly (WASM), Web Workers, and HTML5 Canvas.
- **Zero Server Uploads**: Personal documents, passwords, images, and numbers are never transmitted over the network or logged on external servers.
- **Offline PWA Compatibility**: Service workers cache assets so all tools work seamlessly without an active internet connection.

## Complete Tools Directory

### PDF Tools

- [Compress PDF](https://www.toolfesto.com/tools/pdf-compressor): Compress and reduce PDF file size instantly in your browser. Perfect for shrinking scanned documents and photo-heavy PDFs.
- [PDF Token Optimizer](https://www.toolfesto.com/tools/pdf-token-optimizer): Extract text from PDF documents, clean up unnecessary whitespace, normalize bullets, remove page numbers, running headers, and filter out custom boilerplate content to minimize token count for ChatGPT, Claude, and LLMs.
- [Free PDF Merger](https://www.toolfesto.com/tools/pdf-merger): Combine multiple PDF documents into a single organized file directly in your browser. Fast, free, and completely private.
- [Free Online PDF Editor](https://www.toolfesto.com/tools/pdf-editor): Erase or whiteout existing text, add new text, sign, and draw on any PDF document — entirely in your web browser. No uploads, no signups, 100% private.
- [Split PDF Online](https://www.toolfesto.com/tools/pdf-page-splitter): Split, extract, delete, and reorder PDF pages visually using drag-and-drop. Process documents entirely offline inside your browser for guaranteed privacy.
- [Image to PDF Converter](https://www.toolfesto.com/tools/img-to-pdf): Convert your images to a multi-page PDF securely in your browser. Combine multiple JPGs, PNGs, and photos into a single PDF document instantly.
- [PDF to Image Converter](https://www.toolfesto.com/tools/pdf-to-img): Extract images from your PDF pages securely in your browser. Convert PDF documents to high-quality JPG or PNG files instantly.

### Finance & Math

- [Age Calculator](https://www.toolfesto.com/tools/age-calculator): Free online age calculator with Human and Dog Age modes. Calculate your exact chronological age from your date of birth, or convert your dog's age to human years using science-backed formulas based on breed and size.
- [EMI Calculator](https://www.toolfesto.com/tools/emi-calculator): Calculate your home, car, or personal loan EMIs easily using our free online EMI calculator. Get complete amortization schedules and interest splits.
- [Percentage Calculator](https://www.toolfesto.com/tools/percentage-calculator): Calculate percentages easily with 5 common percentage formulas, including reverse percentage lookups. Great for discounts, tips, growth rates, and math tasks.
- [GST Calculator](https://www.toolfesto.com/tools/gst-calculator): Calculate Goods and Services Tax (GST) easily using our free online GST calculator. Get base prices, tax splits (CGST & SGST), and total net values.

### Text & Content

- [Image to Text (OCR)](https://www.toolfesto.com/tools/image-to-text): Extract text directly from images. Processing happens entirely in your browser—no images or personal data are uploaded.
- [Text Compare Tool](https://www.toolfesto.com/tools/text-compare): Compare two texts side-by-side or unified to highlight differences in lines, words, or characters. Safe, fast, and completely client-side.
- [Password Generator](https://www.toolfesto.com/tools/password-generator): Generate secure random passwords, memorable passphrases, and UUIDs 100% client-side. Evaluate real-time entropy, validate policies, and compute offline SHA/HMAC hashes.
- [JSON Formatter](https://www.toolfesto.com/tools/json-formatter): Format, validate, beautify, and minify JSON text client-side. Find exact line syntax errors instantly with detailed logs.
- [Text Formatter](https://www.toolfesto.com/tools/text-formatter): Free online text formatter and case converter. Easily format text, change letter case (UPPERCASE, lowercase, Title Case, camelCase, snake_case), find & replace text, and clean up text layout instantly.
- [Word Counter](https://www.toolfesto.com/tools/word-counter): Free online word counter to track characters, words, sentences, paragraphs, reading time, and top keyword frequencies in real-time.
- [LinkedIn Text Formatter](https://www.toolfesto.com/tools/linkedin-text-formatter): Format your LinkedIn posts with bold, italic, and sans-serif styles using our free LinkedIn font changer. Live preview your post and see how it will appear on desktop and mobile before publishing.

### Converters

- [Unit Converter](https://www.toolfesto.com/tools/unit-converter): Convert between units of length, weight, area, volume, temperature, speed, time, and digital storage in real-time. Full conversion tables included.
- [Currency Converter](https://www.toolfesto.com/tools/currency-converter): Convert between 200+ world currencies using live, daily-updated exchange rates. Includes USD, EUR, GBP, INR, JPY, and more.
- [Excel & CSV to Markdown](https://www.toolfesto.com/tools/excel-csv-to-markdown): Convert Excel (.xlsx), CSV, GSC & Bing Webmaster exports into token-optimized Markdown tables and AI digests.

### Design & Graphics

- [Online Ruler](https://www.toolfesto.com/tools/online-ruler): Accurate online length and size measurement tool. Measure actual physical size in inches, cm, or mm with multi-edge screen rulers, interactive caliper guides, and instant calibration.
- [QR Code Generator](https://www.toolfesto.com/tools/qr-code-generator): Use our free QR code generator with no sign up required. Create custom QR codes for URLs, text, or Wi-Fi with logo personalization, customize colors, and download them instantly with no expiration.
- [Image Compressor](https://www.toolfesto.com/tools/image-compressor): Use our free image compressor online to shrink JPEG, PNG, and WEBP images in seconds. High-quality client-side compression with zero uploads.
- [Color Converter](https://www.toolfesto.com/tools/color-converter): Convert colors easily between HEX, RGB, HSL, and CMYK formats. Check WCAG contrast compliance and generate beautiful color palettes instantly.
- [Background Remover](https://www.toolfesto.com/tools/background-remover): Remove background from your images automatically in seconds. Free, high-quality, AI-powered background removal running entirely in your browser.

### Health & Fitness

- [TDEE Calculator](https://www.toolfesto.com/tools/tdee-calculator): Calculate your Total Daily Energy Expenditure (TDEE), Basal Metabolic Rate (BMR), and daily calorie needs with our precise online calorie and macro calculator.
- [BMI Calculator](https://www.toolfesto.com/tools/bmi-calculator): Calculate your Body Mass Index (BMI), Waist-to-Height Ratio (WHtR), and Ponderal Index to get a fuller picture of your health screening. Supports metric and imperial units.

## Engineering Deep-Dives & Technical Guides

- [Why pasting raw CSVs into LLMs is costing you a fortune](https://www.toolfesto.com/blog/excel-csv-to-markdown-llm-token-optimization): Raw CSVs waste up to 85% of LLM context tokens and cause arithmetic errors. Compact Markdown slashes API costs and injects deterministic ground truth to prevent hallucinations.
- [Why Background Removers Upload Your Photos](https://www.toolfesto.com/blog/why-most-background-removers-upload-your-photos): Most free background removers send your photo to a server to process it. Here's what that actually means — and a free tool that never uploads your image at all.
- [How Diff Algorithms Work and Private Text Comparison](https://www.toolfesto.com/blog/how-diff-algorithms-work-text-comparison): Learn how LCS and Myers diff algorithms calculate changes between text files, and how client-side processing keeps your code private.
- [Compress Photos Without the Upload Risk](https://www.toolfesto.com/blog/image-compressor-client-side): Every free image compressor uploads your files to a server first. This one compresses JPEG, PNG, and WEBP in your browser — no upload, no risk.
- [Stop Wasting AI Tokens](https://www.toolfesto.com/blog/stop-wasting-ai-tokens): Uploading a PDF straight into Claude or ChatGPT can quietly burn thousands of extra tokens per page. Here's why — and a free browser tool that fixes it before you hit send.
- [Why Most Online Rulers Are Wrong (And How to Fix It)](https://www.toolfesto.com/blog/why-most-online-rulers-are-wrong-and-how-to-fix-it): Discover why most online rulers are inaccurate and how the ToolFesto Online Ruler uses smart screen calibration to provide 100% accurate physical measurements.
- [Why Standard Dog Age Calculators Fail (and the Fix)](https://www.toolfesto.com/blog/why-standard-dog-age-calculators-fail-and-the-fix): The popular '1 dog year = 7 human years' rule is a myth. Discover the real science of dog aging and how I programmed a more accurate, breed-specific calculator.

## Documentation & Deep Context
- [Full LLM Documentation](https://www.toolfesto.com/llms-full.txt): Comprehensive documentation including math formulas, parameter details, and technical FAQs for all tools.
- [Blog & Technical Deep-Dives](https://www.toolfesto.com/blog): Engineering guides on client-side algorithms, diff engines, and PDF optimization.