About Us
A free, privacy-first online toolkit for developers — independently maintained by a working developer
About the Author
I'm Ken, a full-stack developer building web apps and backend services with TypeScript, Go, and Python. Over the years I've needed countless small utilities — format JSON, convert timestamps, compute hashes, generate passwords — so I built this toolkit for myself first, and opened it up for everyone else.
This site is built with Next.js 16 + TypeScript + Tailwind CSS, statically exported and deployed on GitHub Pages. The source code is open.
Every tool is an original implementation, not a wrapper around a third-party API. All algorithms are visible in the lib/ directory of the source.
Who We Are
Ken Webmaster Tools is a free online toolkit built for developers and webmasters. We currently offer 19 browser-based tools covering development, DevOps, security, finance, and everyday utility tasks.
All tools run entirely on the client side. Your data never leaves your device — no backend servers, no uploads, no accounts required. Open DevTools → Network tab to verify: zero API calls, zero tracking beacons, zero data collection.
What We Offer (19 Tools)
- •Development — JSON formatting & validation, regex testing, case conversion, encoding, config format conversion
- •Security — Hash calculation (MD5/SHA/etc), AES/DES/RSA encryption, password generation
- •Conversion — Timestamp & date, Base64 & image, number to Chinese, Roman numerals
- •Practical — BMI/age calculator, loan calculator, world clock, random data, image tools
- •Utilities — QR code generation, Cron expression parsing
Last updated: May 2026 — New tools and improvements added regularly.
Our Principles
Privacy First
All computation happens in your browser. No data is ever sent to any server. You can verify this in DevTools → Network tab — there are no API calls, no tracking beacons, no data collection. This matters when handling sensitive data like source code, configuration files, and encryption keys.
Free & Open
Every tool is completely free with no usage limits, no paywalls, and no registration required. We believe essential developer tools should be accessible to everyone — students, freelancers, small teams, and indie developers alike.
Original Implementation
Every tool is independently implemented, not a wrapper around a third-party API. Encryption leverages crypto-js, config parsing uses js-yaml and smol-toml, and everything else is hand-written logic. Algorithms are visible in the lib/ directory.