ZZTools - Free Online Tools
Private • Instant — Your essential online toolbox
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All processing happens locally in your browser. Your files never leave your device. We don't store, transmit, or access your data.
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No sign-up required to use all core tools. No downloads or installation needed.
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Minimal design, instant access. Tools run directly in your browser — no downloads, no installation, zero wait time.
All Tools
AQHI to AQI Converter - Air Quality Index Converter
Free bidirectional converter between AQHI (Canada's Air Quality Health Index) and AQI (US EPA Air Quality Index) using PM2.5 as the common reference. Supports both AQHI to AQI and AQI to AQHI conversion with the underlying PM2.5 concentration displayed.
Arabic Tashkeel & Harakat Generator
Free online Arabic Tashkeel tool. Add Arabic diacritical marks (Harakat: Fatḥa, Kasra, Ḍamma, Sukūn, Šadda) to Arabic text to aid pronunciation. Features letter analysis, pronunciation guide, and Latin transliteration. Perfect for Arabic learners, teachers, and text preparation. All processing is done locally.
Chinese Name Generator
Free online Chinese name generator. Choose a surname and gender preference to instantly generate authentic Chinese names with pinyin pronunciation and character meanings. Perfect for choosing a Chinese name, naming characters, or exploring Chinese naming culture. All processing is done locally.
Chinese Zodiac Calculator
Free online Chinese Zodiac calculator. Enter your Gregorian birthday to find your exact zodiac animal sign. Accurately calculates based on Chinese Lunar New Year dates, supporting 1900-2100. Includes detailed personality analysis, best compatibility matches, five elements, lucky numbers and colors. All processing runs locally in your browser.
CSS Easing Generator
Free online CSS easing generator. Drag control points to create cubic-bezier curves. Built-in presets for ease, ease-in, ease-out, ease-in-out and linear. Real-time animation preview. All processing happens locally.
Fidelity Annuity Calculator
Free annuity calculator inspired by Fidelity's Guaranteed Income Estimator. Calculate your periodic payment from a lump sum, or determine the principal needed for your desired income. Supports fixed period, lifetime, and joint life annuities with COLA adjustment.
IBAN Validator & Checker
Free online IBAN validator and checker with bank name lookup and SEPA reachability verification. Validate International Bank Account Numbers from 73+ countries. Identify bank name from IBAN, verify bank codes, MOD-97 checksum validation, format verification, country detection, BIC lookup, and SEPA scheme support (SCT, SDD, COR1, B2B, SCC). Supports Germany, France, Spain, Italy, UK, Saudi Arabia, Brazil and more. IBAN format validation runs in the browser; bank name and SEPA data are retrieved from the server.
Batch Image to AVIF Converter
100% Free & Private batch image to AVIF converter. No file upload required — convert HEIC, PNG, JPG, WebP, BMP, TIFF, ICO to next-gen AVIF locally in your browser. Reduce file size up to 50% vs JPG. Supports lossy/lossless modes, quality control, and batch ZIP download.
Batch Image to BMP Converter
100% Free & Private batch image to BMP converter. No file upload required — convert HEIC, PNG, JPG, WebP, AVIF, TIFF, ICO to standard uncompressed BMP locally in your browser. Perfect for raw pixel data processing, with fast batch ZIP download.
Batch Image to ICO Converter
100% Free & Private batch image to ICO converter. No file upload required — convert HEIC, PNG, JPG, WebP, AVIF, BMP, TIFF to ICO locally in your browser. Automatically generates multi-resolution icons (16×16 to 256×256) for website favicons and desktop apps. Supports batch ZIP download.
Batch Image to JPG Converter
100% Free & Private batch image to JPG converter. No file upload required — convert HEIC, PNG, WebP, AVIF, BMP, TIFF, ICO to JPG locally in your browser. Supports adjustable compression quality and fast batch ZIP download.
Batch Image to PDF
100% Free & Private batch Image to PDF converter. No file upload required — merge multiple HEIC, PNG, JPG, WebP, BMP, TIFF images into a single PDF locally in your browser. Supports reordering, rotation, page sizing (A4, Letter), custom margins, and PDF metadata editing.
Batch Image to PNG Converter
100% Free & Private batch image to PNG converter. No file upload required — convert HEIC, JPG, WebP, AVIF, BMP, TIFF, ICO to PNG locally in your browser. Supports transparent backgrounds and fast batch ZIP download.
Batch Image to TIFF Converter
100% Free & Private batch image to TIFF converter. No file upload required — convert HEIC, PNG, JPG, WebP, AVIF, BMP, ICO to lossless TIFF locally in your browser. Ideal for document scanning, OCR preprocessing, and printing. Supports batch ZIP download.
Batch Image to WebP Converter
100% Free & Private batch image to WebP converter. No file upload required — convert HEIC, PNG, JPG, AVIF, BMP, TIFF, ICO to modern WebP locally in your browser. Reduce file size by 25-35% vs JPG. Supports lossy/lossless modes, quality control, and batch ZIP download.
Batch Image Resizer - Stretch, Fit & Cover
100% Free & Private batch image resizer. No file upload required — resize images locally in your browser. Features 3 resize modes (stretch, fit, cover), 10 social media presets, SVG rasterization, HEIC & TIFF input decoding, WebP export, and fast batch ZIP download.
Minecraft Locator Bar Color Checker
Minecraft Locator Bar Color Checker — look up any player's UUID default color, or pick a custom color with the HSV picker and instantly generate a /waypoint modify command. Copy and use in-game. Java & Bedrock Geyser supported.
Matrix Generator
Free online random matrix generator. Supports both integer and decimal matrices with customizable rows, columns and value ranges. Heatmap visualization provides intuitive insight into value distribution. Supports grid and math notation display. All processing is done locally in your browser.
PDF Encrypt & Decrypt
Free online PDF encrypt & decrypt tool. Password-protect your PDF files with AES-256 (PDF 2.0) or RC4 128-bit encryption. Control 8 granular permissions — printing, copying, modifying, and more. All processing is done locally in your browser — your files and passwords never leave your device.
Batch PDF Merger
100% Free & Private batch PDF merger. No file upload required — combine multiple PDF files into a single document locally in your browser. Drag and drop to reorder pages easily, supports unlimited PDF files (up to 50MB per file), with instant one-click merge.
PDF Splitter & Extractor
100% Free & Private PDF splitter. No file upload required — process documents locally in your browser. Preview pages with clear thumbnails, extract single pages or split PDF by custom page ranges, with fast ZIP download support.
Batch PDF to BMP Converter
100% Free & Private batch PDF to BMP converter. No file upload required — convert PDF pages to lossless BMP bitmap format locally in your browser. Preserves every raw pixel with custom DPI settings (72-600) and page range selection. Ideal for professional image editing and printing, with fast ZIP download.
Batch PDF to JPG Converter
100% Free & Private batch PDF to JPG converter. No file upload required — convert PDF pages to highly compatible JPG images locally in your browser. Features custom DPI (72-600), image quality controls, page range selection, and fast ZIP download. Perfect for sharing, printing, and archiving.
Batch PDF to PNG Converter
100% Free & Private batch PDF to PNG converter. No file upload required — convert PDF pages to lossless PNG images with transparent background support locally in your browser. Features custom DPI (72-600), page range selection, and fast ZIP download. Perfect for web design, presentations, and editing.
Batch PDF to TIFF Converter
100% Free & Private batch PDF to TIFF converter. No file upload required — convert PDF pages to high-quality lossless TIFF images locally in your browser. Features custom DPI (72-600), page selection, and ZIP download. Ideal for OCR preprocessing and professional print workflows.
Batch PDF to WebP Converter
100% Free & Private batch PDF to WebP converter. No file upload required — convert PDF pages to modern WebP images (25-35% smaller than JPG) locally in your browser. Features custom DPI (72-600), page range selection, quality controls, and fast ZIP download.
Random Generator
Online random number generator. Supports integers, decimals, passwords, strings and colors. Pure frontend computation.
Batch URL Slug Generator
Free online batch URL slug generator. Converts text from 13 languages (Chinese, Japanese, Korean, Arabic, Russian, and more) into ASCII-friendly URL slugs using transliteration in batch. Supports 5 separator types (hyphen, underscore, dot, tilde, plus), case conversion, stop word filtering, and max length control. All processing happens locally in your browser — nothing is uploaded.
Text Diff Checker
Free online text diff checker and comparison tool. Compare two texts with side-by-side or unified view. Supports word-level, line-level, and character-level diff. Added content highlighted in green, removed in red. Features swap, clear, sample text, copy diff, ignore case, and ignore whitespace options. All processing runs locally in your browser — no data upload.
About zztools.org
zztools.org is a lightweight, privacy-first collection of essential online utilities. From image processing to text conversion, from encryption to data generation — we provide a curated set of tools to help you get everyday tasks done right in your browser.
We believe good tools should be simple, efficient, and respect your privacy. That's why every tool runs entirely in your browser — your data never touches a server.
This site is maintained by independent developers and continuously improved. We welcome feedback and suggestions — and we appreciate everyone who shares zztools.org with others. Let's make online tools better, together.