All the web tools you need, completely free.
Word counters, password generators, QR code creators and more —
free tools to make everyday tasks easier.
Why Yuustudio?
100% Browser-Based
Every tool runs entirely in your browser. No data is ever sent to any server, keeping your personal and sensitive information completely private.
Fast, Free & No Sign-up
No account, no installation, no waiting. Open your browser and start using any tool instantly — all completely free.
Japanese & English
Full UI and documentation in both Japanese and English. Switch languages anytime using the toggle in the header.
Tools
AI Background Remover
Remove image backgrounds with Edge AI — fully in your browser. No upload, no server.
AI Denoiser & Upscaler
Remove noise and upscale images with AI. 2×/4× HD upscaling — fully in your browser.
Image Optimizer Studio
Compress, resize, and convert to WebP/JPEG/PNG in one click. Fully browser-based with automatic EXIF removal.
QR Code Generator & Reader
Create QR codes from URLs, text, or Wi-Fi credentials. Scan QR codes via camera or image upload.
Timer & Cycle Counter
Built for game grinding and Pomodoro sessions. Always-on-top mini window via Document PiP API.
Word Counter
Count characters, words, and lines in real time. Perfect for articles and reports.
Password Generator
Generate strong random passwords in one click. Customize length and character types.
Images to PDF
Combine multiple images into one PDF. Drag to reorder. Fully browser-based and private.
JSON Formatter
Paste JSON to instantly format and validate it. Syntax errors highlighted immediately.
Base64 Converter
Encode text to Base64 or decode Base64 back to text. Full Unicode support.
Grinding Companion
Drop rate probability calculator and cycle counter with per-run timing. Document PiP overlay for gaming.
IP Address Checker
Instantly check your public IP address, location, ISP, and browser info. Completely free.
High-Accuracy OCR (Image/PDF)
Extract text from image/PDF with high accuracy. Local-first processing with privacy in mind.
JSON Schema Validator (schema validation)
High-performance Ajv schema validation with timing metrics and structured error output.
Case Converter (text casing)
Convert one input into 6 naming styles at once for coding, docs, and content formatting.
Text Diff (line comparison)
Compare two texts line-by-line with clear added/removed highlights for fast review.
Slug Generator (SEO URL slug)
Create SEO-friendly URL slugs from titles with lowercase and max-length controls.
UUID Generator (unique IDs)
Generate UUID v4 in bulk and copy all results for test data and mock APIs.
URL Encoder (encode/decode)
Instantly encode or decode URL components for query validation and API debugging.
JWT Decoder (token inspection)
Decode JWT header/payload locally and quickly inspect expiry state.
Cron Parser (schedule preview)
Parse cron expressions and preview upcoming run times before deployment.
Timezone Converter (time shift)
Convert datetime values across IANA timezones with DST-aware calculation.
Image Crop + Rotate
Fast browser-only crop, rotate, flip, and export with real-time preview.
Guides & Articles
About Yuustudio
Yuustudio is a free web tool portal developed and maintained by a university student majoring in Information Engineering. It offers 29+ tools including word counters, password generators, QR code creators, JSON formatters, image compressors, AI background removers, and much more — all designed to streamline everyday tasks.
Every tool runs entirely in your browser, meaning your data is never sent to any server. You can safely use these tools with personal or sensitive information. Built with modern technologies like React, Next.js, and TypeScript, the site delivers a fast and reliable user experience.
Yuustudio is fully available in both Japanese and English, making it accessible to users worldwide. New tools and guide articles are added regularly.