I Built 16 Free Browser-Based Tools So I'd Stop Opening 16 Different Websites

CollateKit — collatekit.com

I kept doing the same thing: need to format some JSON, open a random site, squint at the ads, get my output, close the tab. Repeat for base64, repeat for regex, repeat for UUID generation. So I built one site with all of them.

What it does

16 tools, one place, everything runs client-side:

• JSON Formatter & Validator — paste messy JSON, get it readable
• Regex Tester — live match highlighting as you type
• Base64 Encoder/Decoder
• UUID Generator
• Color Converter — HEX/RGB/HSL, back and forth
• Word Frequency Counter
• Duplicate Line Remover
• Random Line Picker
• Markdown to HTML Converter
• …and a handful more text-manipulation tools I kept needing myself

Why client-side matters here

Nothing you paste gets sent anywhere. Your JSON, your regex, your text — it’s processed in your browser and never touches a server. For tools like this, that’s not a privacy feature I’m marketing after the fact, it’s just how it should work. There’s no reason a JSON formatter needs your data.

How it’s built

• Astro for the site — I wanted static, fast-loading pages with zero JS shipped unless a tool actually needs it
• Tailwind for styling
• Cloudflare Pages for hosting

Astro’s island architecture turned out to be a good fit for “16 independent tools” — each one only loads the JS it needs, so the JSON formatter isn’t shipping code for the color converter.

What’s next

Still adding tools based on what I personally keep needing. If there’s a text/dev utility you reach for constantly and wish existed without ads plastered over it, tell me — genuinely taking requests.

collatekit.com — free, no sign-up, no data leaves your browser.