I built 109 tools that never touch a server - here is the architecture

I built 109 tools that run entirely in your browser, with no server interaction. Every tool on korelyy.com is a static HTML, CSS, and JavaScript file served from a CDN. When you open a tool, the file is read in your browser using APIs like FileReader, canvas, Web Crypto API, and OffscreenCanvas. The file is processed in memory, and the result is downloaded, never leaving your device.

This architecture eliminates the need for a server or any file uploads, ensuring privacy and eliminating potential data leaks. The key APIs that enable this zero backend approach include FileReader, URL.createObjectURL, crypto.subtle for client-side cryptography, canvas and OffscreenCanvas for image manipulation, and Web Workers for offloading CPU-intensive tasks.

While this approach has limitations, such as the inability to support shared databases, third-party APIs with secrets, or heavy server-side processing, it provides significant benefits in terms of speed, privacy, and cost-effectiveness. The author of korelyy.com built 109 tools, with 30 considered great, 60 decent, and 29 mediocre.

The site achieves excellent SEO performance with Lighthouse scores of 100/100/100/100 on every page and a total page weight under 50KB. Despite the low traffic numbers, the cost per impression is $0, and the trend shows a monotonically increasing pattern. The author advises against adding a backend unnecessarily and recommends conducting market research before building tools.

The no-backend approach is not suitable for multiplayer products, authentication systems, ML inference, heavy server-side processing, or products requiring comprehensive analytics, but it can be a valuable strategy for solving specific problems with minimal overhead.