I Built 75+ Free Developer Tools — Here's What I Learned

Hey everyone! I’m jinyuan, an indie developer. I recently launched DevTools Box — a free online toolbox with 75+ developer tools.

What’s in the box?

DevTools Box includes tools like:

• JSON Formatter — beautify and validate JSON
• Regex Tester — test regular expressions with live matching
• Base64 Encoder/Decoder — quick encoding and decoding
• QR Code Generator — generate QR codes instantly
• Hash Calculator — MD5, SHA-1, SHA-256 and more
• Color Picker — pick colors and convert between formats
• …and 69 more tools!

Why I built it

I was tired of jumping between different websites for simple dev tasks. Each tool runs entirely in your browser — no login, no ads, no data sent to any server.

Tech stack

• Next.js 14 with App Router
• TypeScript
• Tailwind CSS
• Static export to Cloudflare Pages

Try it out

Check it out at tdboxs.com. All tools are 100% free.

Would love to hear your feedback! What tools would you add?