About Dev Tools !

A privacy-first, open-source suite of developer utilities built with love by Cosyslabs.

Our Mission

Developers shouldn't have to choose between convenience and privacy. Too many online tools send your sensitive data — JWTs, passwords, hashes, source code — to servers you don't control.

Dev Tools ! runs 100% in your browser. No server round-trips for tool processing. No tracking of your inputs. No paywalls for core features.

Open Source Philosophy

We believe developer tools should be transparent and auditable. Dev Tools ! is fully open source under the MIT licence. You can inspect the code, fork it, self-host it, or contribute new tools.

⭐ View on GitHub →

Tech Stack

React 18
UI library
TypeScript
Type safety
Vite
Build tool
react-router-dom
Routing
react-helmet-async
SEO meta tags
react-i18next
Internationalisation
Cloudflare Workers
Edge API & CDN
Hono
Edge runtime framework

About Cosyslabs

Cosyslabs is an independent software studio focused on building useful, privacy-respecting tools for developers. We're a small team with a big belief: software should serve its users, not the other way around.

Visit cosyslabs.com to learn more about our studio and the people behind it.

Part of the Cosyslabs Family

Dev Tools ! is part of a growing family of free, privacy-first tools built by Cosyslabs:

  • Astrilio — Free property management calculators for landlords and real estate investors
  • RoughEstimator — Quick construction and renovation cost estimators
  • UnitConvertAll — Comprehensive unit and measurement converters
  • PDFConvertAll — Free PDF conversion and compression tools
  • RoutineToolkit — Everyday productivity and routine calculators
  • CastFleet — Content calendar and social media management
  • Cosyslabs — The company portfolio and studio behind all these tools