Quasar
An all-in-one, privacy-first developer tools suite with 120+ data and code utilities that run entirely client-side. Built on a registry-driven architecture where a single source of truth powers routing, navigation, fuzzy search, and SEO — adding a tool is one entry plus a pure, fully tested engine function.
Overview
A large multi-tool web app — JSON/XML/CSV/SQL converters, color and unit converters, string utilities, diffs, and more — all running in the browser with zero uploads. A central tool registry drives the entire app so the surface scales to 120+ tools without per-tool boilerplate.
Problem
Online code and data tools scatter functionality across dozens of ad-heavy sites, often uploading sensitive input to remote servers and breaking when offline.
Solution
Consolidated 120+ tools into one offline-capable PWA. Every tool is a registry entry pointing to a thin React component backed by a pure engine function, so the framework handles routing, SEO, search, and sessions automatically.
Architecture
Next.js 15 App Router with static export. A single dynamic route /tools/[id] renders any tool from the registry, with generateStaticParams pre-rendering all pages. Pure, framework-free engines (color, data, string, unit, diff, html, sql) are unit and property tested with Vitest + fast-check. Serwist provides the offline service worker.
Results
120+ tools driven by a single registry — adding a tool is one entry
Fully client-side and offline-capable as an installable PWA
Static export with every tool page pre-rendered at build time
Pure engines covered by property-based tests (Vitest + fast-check)
