Signing in sets session cookies, issued by our authentication library. They identify your session so the application knows you are signed in and can protect your models from other accounts. They are the only cookies we set.

These are strictly necessary: without them you cannot sign in, and the service cannot be provided. Blocking them in your browser will prevent you from using an account, though the free calculators remain usable signed out.

We keep a small number of settings in your browser's local storage. These never leave your device and are not cookies; clearing your site data removes them.

• Your chosen interface language.
• Grid, view and panel-layout settings for the model editor.
• Whether you have dismissed the onboarding banner or tour.
• Unsaved editor drafts, so a reload does not lose work in progress.

We use Sentry to find out when the application breaks. Sentry receives:

• Errors, every time one occurs, including the technical context needed to diagnose it.
• Performance traces, for about 1 in 10 page loads.
• Session replay, for about 1 in 10 sessions, and for any session in which an error occurs. A replay is a reconstruction of what happened in the page — navigation, interaction and page content.

Sentry is configured to include personally identifying information where it is available, which in practice means the account associated with a session and the IP address the request came from. This is used to diagnose faults and to tell whether a problem affects one customer or all of them. It is not used for profiling, marketing or advertising.

If you would rather not be included in session replay, write to privacy@ferscloud.com and we will exclude your account.

We do not use advertising cookies, analytics cookies, social-media pixels, or any third-party tracker. We do not sell or share browsing data. There is no cookie banner because there is nothing here that would require consent beyond what is strictly necessary to sign you in — and if that changes, this page and the banner will change with it.

Every browser can block or delete cookies and site data, usually under privacy or site settings. Deleting ours will sign you out and reset your interface preferences. Nothing you have saved to your account is affected — models live on our servers, not in your browser.

For what happens to personal data more generally, including your rights of access, export and deletion, see our Privacy Policy. For who we are, see the Legal Notice.