i4u - 60+ Free Online Tools
i4u.jp offers image editing, PDF processing, text conversion, developer tools, and more - all running in your browser. With the spirit of "for you", everything is free and ready to use.
Popular Tools
Voice T-Shirt Maker
Record your voice and create a T-shirt with waveform design. Playable via QR code
Image Format Converter
Convert image formats
Image Resizer
Resize and compress images to optimize file size
Text Diff Comparison
Compare two texts and visualize differences
JSON Formatter & Validator
Format, minify, validate, and display statistics for JSON.
Base64 Converter
Convert text or files to Base64 format and decode
PDF Merger & Splitter
Merge multiple PDF files or split a single PDF into multiple files
QR Code Generator
Convert text, URLs, WiFi settings into QR codes
Password Generator
Generate secure and strong passwords
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Latest Guides
Color Palette Design: Complete Guide to Creating Stunning Color Schemes
Master the art of color palette design with comprehensive theory, practical techniques, and tools for creating harmonious color schemes for any project.
File Compression Guide: Complete Guide to Reducing File Sizes
Master file compression techniques, understand different algorithms, and learn to optimize storage and transfer speeds while maintaining quality.
Image Optimization Techniques: Complete Guide to Web Performance
Master image optimization for faster websites - learn compression, format selection, responsive images, and modern techniques for optimal web performance.