About
Tools that work for you, not on you.
OpenToolLab is a collection of free developer tools built on one principle: your data should never leave your device.
Every developer has pasted a JSON payload, a regex, or a config file into an online tool — and most of those tools upload your data to their servers. In November 2025, a widely used formatter site leaked over 80,000 files and 5 GB of user data. That's not a rare failure; it's the natural result of a server-based architecture.
OpenToolLab takes the opposite approach. Every tool runs 100% client-side in your browser. There is no server processing, no upload, no account, and no tracking. Your data never leaves your machine — you can verify this in your Network tab.
This design makes our tools faster (no network round-trips), more reliable (they work even if our servers are down), and genuinely private (there is nothing to store, log, or leak).
Other tools we've built
Beyond OpenToolLab, we build focused, in-browser calculators for everyday problems — always free, always client-side.