About DevKits
DevKits is a collection of 38+ free online tools built for developers. The goal is simple: provide fast, reliable, privacy-respecting utilities for the small tasks that fill a developer's day — formatting JSON, decoding a token, converting a timestamp, hashing a string, generating a UUID — without the friction of sign-ups, paywalls, or invasive tracking.
Our privacy-first principle
Most "online" developer tools send whatever you paste to a remote server for processing. For a lot of real work — inspecting a production API response, decoding a JWT, hashing sensitive input — that is unacceptable. Every tool on DevKits is implemented as client-side JavaScript and runs entirely inside your browser. Cryptographic operations use the browser's native Web Crypto API. Your data is processed on your own machine and is never uploaded, logged, or stored by us. Most tools even keep working offline once the page has loaded.
How the tools are built
The site is built with Next.js and TypeScript and deployed as static pages, which is why it loads quickly and stays reliable. Each tool is more than a text box: we add plain-language explanations, real-world use cases, multi-language code examples, and notes on the edge cases and pitfalls that trip developers up. Where a standard exists — RFC 8259 for JSON, RFC 4180 for CSV, RFC 7519 for JWT — we cite it and follow it, so the output matches what your production libraries expect.
Who builds it
DevKits is built and maintained by a working software developer who uses these same utilities daily. It started as a set of personal tools and grew into a public collection. Occasional build notes and behind-the-scenes write-ups are published on dev.to.
How this stays free
The tools are and will remain free to use. There are no accounts and no data harvesting. If the site ever shows advertising or offers optional paid features, it will be clearly disclosed and will never compromise the core promise: your input stays in your browser.
Feedback
Found a bug, or want a tool that isn't here yet? Suggestions are welcome via the contact page. Requests that many developers share tend to get built first.