These aren’t “learn to code” sites. These are tools working developers use regularly.

Daily use

1. DevDocs.io

Unified documentation for every language and framework. Offline-capable, fast search, clean interface. Better than googling “MDN array methods” every time.

2. Can I Use

Check browser support for any CSS or JavaScript feature. Before using container queries or Array.groupBy(), check here first.

3. Regex101

Write, test, and debug regex with real-time explanation. Paste your regex, paste your test string, see what matches and why. Supports multiple flavors (JS, Python, Go, PHP).

Weekly use

4. Bundlephobia

Check the size of any npm package before installing it. Shows minified size, gzipped size, and download time. Think twice before adding a 200KB dependency.

5. Transform Tools

Convert between formats: JSON ↔ TypeScript, HTML ↔ JSX, JSON ↔ YAML, CSS ↔ Tailwind, and dozens more. Saves writing conversion code by hand.

6. Excalidraw

Hand-drawn-style diagrams. Perfect for architecture diagrams, flowcharts, and explaining systems in PRs or docs. Collaborative, free, no account needed.

7. Carbon

Create beautiful code screenshots for presentations, blog posts, and social media. Choose theme, language, and export as PNG.

When you need them

8. Explain Shell

Paste any shell command and get a breakdown of every flag and argument. Perfect for understanding someone else’s bash script.

9. httpstat.us

Returns any HTTP status code you want. Testing error handling? curl httpstat.us/503 gives you a 503. Simple and useful.

10. JSON Crack

Visualize JSON as an interactive graph. When you’re dealing with deeply nested API responses, this makes the structure obvious.

11. Squoosh

Image compression in the browser. Drag an image, choose format (WebP, AVIF), adjust quality, see the size difference in real-time. By Google.

12. Hoppscotch

Open-source API client in the browser. Like Postman but faster, lighter, and no account required. Send requests, see responses, save collections.

The bookmark strategy

Don’t bookmark all 12. Open each one, try it for 30 seconds, and bookmark the ones that solve a problem you actually have. Three bookmarks you use beat twelve you forget about.

My personal top 3 that I use almost daily: DevDocs (faster than googling docs), Excalidraw (every architecture discussion), and Squoosh (every blog post image). The rest I reach for when I need them — but knowing they exist saves me from building or paying for something that’s already free.

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