About TinyUseful
TinyUseful is an independent utility site made in Prague: small browser-based calculators for everyday decisions.
Who built this?
TinyUseful was created by Lukáš, an architect from Prague.
The idea started with friends in the U.S. who kept jumping between search results, apps, AI answers, and cluttered calculator sites just to solve small everyday questions.
So he built a quieter alternative: fast, simple calculators that work in the browser and get out of the way.
Useful enough for a construction site. Simple enough for a kitchen counter.
Why TinyUseful exists
Most calculator websites are bloated with ads, tracking, account walls, AI assistants, and explainers that bury the answer below the fold. We wanted something different — a calm place where the math is the point and everything else gets out of the way.
Eleven small tools, one per page. Each one does a single thing well. No bundle, no upsell, no “sign up for the full version.” The full version is what you see.
Why no AI
AI is useful for messy questions. These tools are for questions with one clear answer: a tax amount, a tip, a date, a monthly payment. The formulas are deterministic, run in your browser, and do not guess.
For when you don’t need a chat — just the answer.
How the calculators work
Every tool uses simple deterministic formulas, computed entirely in your browser using vanilla JavaScript. The math behind the money tools is the standard textbook amortization and percentage formulas — the same ones a bank’s internal calculator uses. No external lookup, no API call, no “model.”
You can verify any result with a pencil if you want. That is the whole point.
What we do not save
Calculator inputs stay in your browser. The numbers you type into a tool are processed locally in JavaScript and are never sent to TinyUseful. We do not require an account, an email, or a sign-up.
Page requests, basic analytics (Cloudflare cookieless server-side, no personal identifiers, no cross-site follow), consent choices, and advertising services may involve third-party processing — full disclosure on the Privacy page.
Why the source is public
The full source code lives on GitHub at github.com/jetotakto/tinyuseful. Anyone can read the formulas, audit the JavaScript, and confirm that no input ever leaves the page.
It is not a strategy. It is the only honest way to claim that calculator inputs stay in your browser.
How ads may work later
The plan is one declared advertising slot per page, served by a reputable ad network such as Google AdSense. One clearly labelled box, in the middle of the page, between the tool and the explainer. No popups. No interstitials. Ads and related services may use cookies where applicable.
That is the entire business model. We sell attention to advertisers in one box, so the tools can stay free and account-free.
Contact
Bug reports, ideas, feedback — contact@tinyuseful.app.
TinyUseful · Issue No. 1 · April 2026
Made in Prague, Czech Republic.