Free Reference Tools

Quick reference tools for developers and tech enthusiasts. Check browser compatibility for web features, detect technologies used by any website, and browse developer cheat sheets.

Answers Without Searching Documentation

How many times have you opened a new tab to check whether a CSS property works in Safari, or which JavaScript feature requires a polyfill for older browsers? Or wondered what tech stack a competitor's website uses? Reference tools save you from digging through scattered documentation, Can I Use tables, and GitHub repos to find quick answers.

Available Reference Tools

Can I Use — Browser Compatibility Checker

Search any CSS property, JavaScript API, or HTML feature and see browser support across all major browsers and versions. See global usage percentages, known issues, and polyfill recommendations. Powered by caniuse.com data — the standard reference for web developers worldwide. Whether you're deciding to use CSS Grid in a production app or checking if Intersection Observer works in Safari, this tool gives you instant answers.

Tech Stack Detector

Enter any website URL and see what technologies it uses — frameworks, libraries, CMS platforms, analytics tools, CDNs, and hosting providers. Detects React, Vue, Angular, WordPress, Shopify, Google Analytics, Cloudflare, AWS, and hundreds of other technologies. Useful for competitive research, technology scouting, and satisfying curiosity about how your favorite sites are built.

Developer Cheat Sheets

Browse quick reference guides for JavaScript, Python, React, Git, CSS, SQL, Regex, Markdown, and more. Each cheat sheet covers the most commonly used syntax, methods, and patterns — perfect for when you know what you want to do but forgot the exact syntax. No more scrolling through full documentation for a quick method name or flag.

How to Use Reference Tools in Your Workflow

Check compatibility before using new features. Before committing to a new CSS or JavaScript API in a project, verify browser support with Can I Use. A two-second check can save hours of debugging in legacy browsers.

Research before building. The Tech Stack Detector helps you understand what technologies successful sites in your space are using. This can inform your own technology choices and help you stay current with industry standards.

Keep cheat sheets open while coding. Open a cheat sheet in a pinned tab or second monitor. The visual layout of our cheat sheets makes scanning faster than reading documentation pages line by line.