Small tools, transparent methods.

Smile Tools is an open-source collection of focused calculators and developer utilities. Each tool is designed to finish one practical task without an account, while related suites let you reuse the same input across a longer workflow.

Privacy by design

Calculator measurements and pasted JSON are processed by code running in your browser. The tools do not submit those inputs to a Smile Tools application server. See the privacy page for the project’s data-handling approach.

Formula and content standards

Health-related calculators identify the equation used, link to primary research or public-health guidance, and clearly label results as educational estimates. Developer tools explain the limits of generated output so a convenient draft is not mistaken for a verified production contract.

Open development

The source code and change history are available on GitHub. If a formula, explanation, accessibility detail, or result looks wrong, please open an issue with a reproducible example.