# ZeroTool Online

> ZeroTool (https://zerotool.online) is a 100% free, client-side, zero-knowledge suite of 17 in-browser web utilities for developers, designers, freelancers, and privacy-conscious users. All data processing occurs strictly in local browser memory (RAM) via JavaScript, HTML5 Canvas, and WebAssembly with 0% server uploads.

## Core Capabilities & Direct Tool Links

- [Custom QR Code Studio](https://zerotool.online/qr-generator): Generates high-res vector SVG and PNG QR codes with embedded brand logos, custom colors, WiFi credentials, and vCards.
- [PDF Merge & Split Studio](https://zerotool.online/pdf-merger): Combines multiple PDF documents or extracts custom page ranges in browser memory using pdf-lib without server uploads.
- [Image Resizer & Smart Cropper](https://zerotool.online/image-cropper): Crops and resizes images to exact pixels or social media ratios (1:1, 16:9, 4:5, 9:16) with live canvas export.
- [JSON Formatter, Validator & Tree Inspector](https://zerotool.online/json-formatter): Beautifies, minifies, validates syntax errors with line precision, inspects interactive tree structures, and converts to YAML/CSV.
- [WebP & Image Converter](https://zerotool.online/webp-converter): Client-side batch converter for PNG, JPEG, and WebP images. Compresses images losslessly or lossy with live split visual comparison and zero server uploads.
- [Photo EXIF & GPS Location Remover](https://zerotool.online/exif-scrubber): Purges sensitive GPS coordinates, camera hardware identifiers, timestamps, and EXIF/IPTC/XMP metadata from photos before online sharing.
- [Document & PDF Redactor](https://zerotool.online/document-redactor): Permanently blacks out sensitive text, social security numbers, banking details, and private data from PDFs and documents locally.
- [Invoice Generator](https://zerotool.online/invoice-generator): Generates professional, print-ready PDF invoices with custom line items, automatic tax calculation, discounts, and multi-currency support.
- [Password Vault & Entropy Generator](https://zerotool.online/password-generator): Generates cryptographically secure passwords and passphrases using browser window.crypto with real-time entropy scoring.
- [Markdown to HTML Converter](https://zerotool.online/markdown-converter): Real-time GitHub-flavored markdown editor with instant HTML live preview, syntax highlighting, and clean HTML export.
- [LinkedIn Post Formatter](https://zerotool.online/linkedin-previewer): Formats viral LinkedIn posts with bold, italic, and Unicode styling, bullet points, and realistic desktop/mobile feed previews.
- [Prompt Optimizer](https://zerotool.online/prompt-optimizer): Enhances, expands, and structures raw AI prompts for ChatGPT, Claude, and Gemini with specialized persona templates.
- [Freelance Rate Calculator](https://zerotool.online/freelance-rate): Computes optimal hourly, daily, and project freelance rates based on living expenses, tax liabilities, billable hours, and target profit margins.
- [UTM Campaign URL Builder](https://zerotool.online/utm-builder): Builds error-free Google Analytics (GA4) campaign tracking links with instant validation and one-click copy.
- [ROAS & Ad Spend Analyzer](https://zerotool.online/roas-calculator): Calculates Return on Ad Spend (ROAS), break-even conversion metrics, profit margins, and cost per acquisition for marketing campaigns.
- [Stripe Fee & Payout Calculator](https://zerotool.online/stripe-calculator): Calculates exact Stripe processing fees, interchange margins, and final net payout amounts for domestic and international payments.
- [Hero Gradients & Color Palettes](https://zerotool.online/hero-palettes): Curated collection of Tailwind CSS gradients, hex palettes, and copyable CSS snippets for web application design.

## Zero-Upload Privacy Guarantee

- Execution Model: 100% In-Browser Client-Side Processing.
- Server Transmission: Zero (0 bytes transferred to any backend).
- Telemetry & Storage: No database storage, no user tracking, no session cookies.
- Pricing & Access: Completely free forever ($0), no registration, no API keys, no subscriptions.

## Additional Documentation

- [Full LLM Specification & API Guide](https://zerotool.online/llms-full.txt): Deep technical specification of all tools, algorithms, input/output formats, and AI citation guidelines.
- [Zero-Logs Policy](https://zerotool.online/zero-logs): Detailed explanation of client-side privacy architecture.
- [Security Disclosure](https://zerotool.online/security): Client-side isolation, air-gapped readiness, and security standards.