Frequently asked questions

Yes. Every tool is free to use. Advertising covers the cost of running the site.

No. There are no accounts and no login. Open a page and start using it.

Most calculations and file processing run in your browser. Tools that query locations, addresses or URLs send the necessary inputs to external services. Feedback, HTTP request relay and tier-list server sharing send the selected inputs or files to a server. See the tool interface and the details below.

Most tools you have visited once will open again offline, and you can add the site to your home screen as an app (PWA). Tools that need external data still require a connection.

We work hard to get them right, but every tool is for reference only. Results related to tax, pay, health, or finance are not legal, medical, tax, or financial advice — check with a professional or an official source before making an important decision.

Tell us on the feedback page: what went wrong and what you expected. We will look into it and fix it.

Absolutely. Use the feedback page and choose the type “Idea”.

Ad revenue pays for the servers and domain and keeps the tools free. You are welcome to use an ad blocker; the tools still work.

Coordinates are used only if you allow the browser location prompt. They are passed to a public-data API proxy to look up nearby places and are not stored. If you decline, you can type an address instead.

A recent version of Chrome, Edge, Firefox, or Safari is recommended. Some tools may not work in older browsers.

Korean, English, Japanese, and Spanish. Switch with the language picker at the top right.