🛠️ Free Developer Tools

25+ tools that run in your browser. No signup, no tracking, no ads.

No tools match your search. Try different keywords.

🔒 Security

Password Strength Analyzer

Entropy-based scoring with real-time crack-time estimates

Password Generator

Generate secure random passwords with custom rules

MD5, SHA-1, SHA-256, SHA-512 hash any text instantly

Dev Security Checklist

Essential security checklist for web developers

AI Security Checklist

Security best practices for AI/ML applications

📝 Code & Text

Format, validate, and beautify JSON with syntax highlighting

JSON Error Explainer

Paste broken JSON — get human-readable error explanations

Test regular expressions with real-time matching and groups

Compare two texts and see differences highlighted

Markdown Preview

Live markdown editor with instant preview

Lorem Ipsum Generator

Generate placeholder text for your designs

🔧 Encoding & Conversion

Decode and inspect JSON Web Tokens instantly

Base64 Encoder/Decoder

Encode and decode Base64 strings

URL Encoder/Decoder

Encode and decode URL components

Unix Timestamp Converter

Convert between Unix timestamps and human dates

Generate v4 UUIDs instantly for your projects

🎨 Design & CSS

Pick colors in HEX, RGB, HSL with palette generation

CSS Gradient Generator

Create beautiful CSS gradients with live preview

Box Shadow Generator

Design CSS box shadows with visual controls

💰 Finance

💰 DonFlow — Plan vs Reality Budget Tracker

Set a budget plan, upload bank exports, see where reality drifts. 100% browser-only, zero tracking. Your financial data never leaves your device.

⚡ Productivity

Explain cron expressions in plain English with next run times

Generate keyword combinations for SEO and ads

Quick audit of any website's SEO and performance

QR Code Generator

Generate QR codes for URLs, text, WiFi, and more

Focus timer with break reminders

Image Compressor

Compress images in-browser without uploading

DevTools Collection

Multi-tool dashboard for quick dev tasks

🎮 Popular Browser Games

Free browser games — no download, no signup. Play instantly.

🧩 Block Puzzle

Tetris-style block stacking. Clear lines, chase high scores.

🐍 Snake Arena

Classic snake game with modern graphics and power-ups.

🃏 Solitaire Tower

Card-matching solitaire with tower mechanics.

💣 Minesweeper

Classic minesweeper logic puzzle. Flag mines, clear the field.

🐦 Gravity Bird

Tap to fly through obstacles. How far can you go?

🫧 Bubble Shooter

Match and pop colorful bubbles. Aim, shoot, clear!

🏰 Tower Defense

Build towers, upgrade defenses, survive enemy waves.

⚔️ Dungeon Descent

Roguelike dungeon crawler. Fight monsters, collect loot.

🏃 Maze Runner

Navigate procedural mazes. Speed and strategy matter.

🔨 Whack-a-Mole

Test your reflexes — whack moles before they hide!

Type falling words before they hit the ground.

Speed math quiz — solve equations before time runs out.

🎲 Random Defense

Summon random units, merge to evolve, defend 25 waves.

See all 27 games →

📦 More

🛒 Gumroad Store — Dev Templates & Cheatsheets

Notion templates, dev cheatsheets, prompt packs, and productivity bundles. Support the tools you love!

Tutorials, AI tips, and developer productivity articles

❓ Frequently Asked Questions

Are all these tools really free?

Yes — 25+ tools, completely free. No signup, no ads, no usage limits. Every tool runs 100% client-side in your browser. The source code is on GitHub.

Do you collect my data?

No. Every tool processes your data entirely in your browser using JavaScript. Nothing is uploaded to any server. Check the Network tab in DevTools — zero outgoing requests with your data.

Can I use these tools offline?

Most tools work offline once loaded since they are pure client-side HTML/CSS/JS. Bookmark the page and use it without internet.

What is DonFlow?

DonFlow is a local-first budget tracker that compares your planned budget against actual spending. It detects "budget drift" — where reality diverges from your plan. Your financial data never leaves your browser. Try the demo →

How do I share a tool result with my team?

Many tools have a 🔗 Share button that encodes your input into a URL. Send the link to anyone — they'll see exactly what you see, no signup required.

🚀 Built 25+ tools. Wrote 50+ articles. Here's the shortcut:

All the knowledge packed into searchable cheat sheets — Git, Docker, SQL, System Design, Frontend & more.

⭐ Developer Cheat Sheet Bundle — $7 →

Best value · Browse all 9 resources → · Free previews available