I've been using JSON formatters, cron schedulers, password generators and Base64 encoders since my first day as a web developer. Always jumping between tabs, always the same ugly interfaces from 2012.
Then last year JSONFormatter.org and CodeBeautify.org made the news — years of user data exposed. Passwords, API keys, cloud credentials. Stuff developers had been pasting there assuming it was safe.
That was enough for me.
So I built devessentials.dev — a collection of the tools I actually use, running 100% in your browser. No backend. No server ever sees what you paste. You can verify it yourself: open
DevTools → Network tab, use any tool, watch zero requests go out.
What's in it
- JSON Formatter, Validator & Beautifier
- JWT Decoder & Debugger
- Hash Generator (MD5, SHA-256, SHA-512)
- Base64 Encoder/Decoder
- UUID Generator (v1, v4, v7)
- Password Generator & Strength Checker
- Cron Builder
- Diff Checker
- URL Encoder/Decoder
- JSON ↔ YAML, JSON ↔ CSV converters
- JSON Repair (great for fixing broken LLM output)
Tech
Built with Next.js 15, fully static. No ads, no login, no analytics on your inputs.
What's next
Adding more tools as I need them. Feedback welcome.
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