Every developer has those repetitive micro-tasks that silently eat hours each week. Formatting JSON, debugging regex, decoding JWTs… I got tired of bouncing between random sites full of ads, so I built my own.
Here are 5 browser tools I use daily. They’re all free, client-side, no signup, no tracking.
1. JSON Formatter & Validator
The problem: Pasting minified JSON into random online formatters that inject ads or (worse) send your data to a server.
The fix: A clean formatter with syntax highlighting, validation, and error messages — all running in your browser. Zero data leaves your machine.
2. Regex Tester & Debugger
The problem: Writing regex blindly, running code, failing, tweaking, repeat. Classic pain loop.
The fix: Real-time matching with capture group highlighting. You see exactly what your pattern matches (and what it doesn’t) as you type.
3. JWT Decoder
The problem: Copying JWTs from auth responses and pasting them into jwt.io every single time. It works, but it’s slow and cluttered.
The fix: Paste a token, instantly see the decoded header and payload. Clean UI, no server calls, nothing stored.
4. Cron Expression Parser
The problem: Staring at 0 */6 * * 1-5 and mentally computing when it fires. Every. Single. Time.
The fix: Paste any cron expression, get a plain-English explanation plus the next 5 scheduled run times. No more guessing.
5. Diff Checker
The problem: Two config files that should be identical but clearly aren’t. Finding the difference manually is brutal.
The fix: Paste both texts, get a highlighted side-by-side diff instantly. Great for comparing configs, API responses, or code snippets.
Why I Built These
I wanted tools that:
- Run 100% client-side (your data never leaves the browser)
- Have zero ads, zero signups
- Load fast and just work
There are 25+ tools on the site covering security, encoding, CSS, and more.
Check them all at 👉 maxmini0214.github.io
If any of these save you time, a ⭐ on GitHub means a lot. Happy coding!