# Quality and privacy

This chapter describes what is checked before a page is published, and what happens to what you type into a calculator.

## Validation before publishing

- Every page is checked automatically before it is published, and an error stops publishing.
- Every language link points to a page that exists. A link to a missing page stops publishing.

- A new calculator must pass test cases with expected values from a named source, such as an official calculator, a textbook or a standard, before it is published.
- Existing calculators are checked one category at a time, with real keystrokes in a browser, in every language they exist in. A category is closed when every calculator in it has passed.
- Existing calculation logic is changed only to fix a documented defect, and each fix has its own written decision.

- Numbers are shown in the format of the page's language, for example with a decimal point on the English pages and a decimal comma on the Norwegian ones, whatever language the browser uses.
- Each language version is written in that language. Another version may serve as a template for the structure, but the text is not translated word for word.

- The site has no ads and no sign-up.
- A calculator works out the answer in your browser, and what you type into it is not sent to us.
- Visitor statistics are collected without cookies.