Guides &
Deep Dives
In-depth articles on web development, design, security, and content strategy — each paired with a free tool so you can practice what you read.
Hanul Lee
@lnuvyFrontend developer with 4+ years of experience building production apps with React, Next.js, and TypeScript. I build these tools and write about what I learn along the way.
Building a QR Code Generator in React: What I Learned
A developer's journey building a client-side QR code generator — library choices, WiFi format quirks, color contrast pitfalls, and SVG vs PNG export.
Why Math.random() Is Dangerous: Building a Secure Password Generator
Learn why cryptographic randomness matters and how I built a password generator using Web Crypto API instead of Math.random().
Client-Side Image Compression: Canvas API Pitfalls I Wish I Knew
The surprising limitations of browser-based image compression — PNG quality ignored, EXIF data stripped, and why WebP is the real winner.
YouTube Thumbnails: Complete Guide to Boosting CTR
Learn the science behind high-performing thumbnails — optimal sizes, design psychology, A/B testing, and competitive analysis.
Complete Guide to Password Security (2026)
Everything you need to know about creating strong passwords, enabling 2FA, and protecting your accounts from data breaches.
Image Optimization for Web: Complete Guide
Learn how to reduce image file sizes by up to 80% without losing quality. Compare JPEG, PNG, WebP, and AVIF formats.
QR Codes: Complete Guide to Creating & Optimizing
From technology and history to security, design best practices, and real-world business applications of QR codes.
JSON for Developers: Complete Data Interchange Guide
Master JSON from its origin and philosophy to common mistakes, modern usage patterns, and JSON Schema validation.
Web Colors, Gradients & Shadows: CSS Design Guide
Master CSS visual design — color systems, color theory, gradient techniques, box shadow depth, and design token architecture.
PDF & Document Conversion: Complete Guide
Master document formats — PDF, TIF, and image conversion, optimization techniques, government submission requirements, and best practices.
YouTube Embedding: Complete Guide to Responsive Video Embeds
Master YouTube video embedding — responsive iframes, privacy-enhanced mode, autoplay, custom parameters, and accessibility best practices.
Base64 Encoding: A Complete Developer's Guide
Understand Base64 encoding from the ground up — binary-to-text conversion, Data URIs, JWT tokens, email attachments, and performance considerations.
Placeholder Text in Design: History, Uses & Best Practices
Explore the 2000-year history of Lorem Ipsum, when to use placeholder text, alternatives for different languages, and design workflow best practices.
Text Case Conventions: A Developer & Writer's Guide
Master text case conventions — camelCase, snake_case, kebab-case for code, and Title Case vs Sentence case for writing and UI design.
About This Publication
Global Free Tools is a knowledge-driven publication for developers, designers, and content creators. We believe every tool deserves context — so we write expert-level guides explaining the why before the how. All tools run entirely in your browser with zero data collection.
Published by the Global Free Tools editorial teamFree Online Tools
Practice what you learn — every article has a matching free tool.