Privacy

Local by default

The installed extension saves your birthday and related settings in your browser extension’s local storage. This includes your birth date and time, birth time zone, optional sex-at-birth value, life-expectancy choice, theme, counter mode, numeral style, reflection setting, and language.

The online demo uses this browser’s local storage instead. Nothing is synced unless you turn sync on in Settings.

Optional browser sync

Sync has two separate opt-ins. The second is available only after you enable the first.

Preferences

Sync preferences across devices syncs only your theme and custom colors, counter mode, numeral style, reflection setting, and language.

Personal profile

Also sync birthday and life-expectancy details additionally syncs your birth date and time, birth time zone, optional sex-at-birth value, and selected life-expectancy data source or custom number of years.

When enabled, Mortality writes these fields to your browser vendor’s account and sync-storage service. Google, Mozilla, or Microsoft provides that service, depending on your browser. Mortality also stores limited technical sync metadata: enabled scopes, a random writer ID, schema version, and update time. These records let devices reconcile changes; they are not sent to Mortality.

No Mortality account or backend

Mortality has no account system, app backend, analytics, advertising, or developer access to your local or synced settings. The extension does not send those settings to Mortality’s developer.

This policy page and the online demo are hosted by GitHub Pages. Mortality adds no analytics, advertising, or tracking scripts to them.

Disable sync and remove synced data

Open Settings → Device sync:

• Turn off Also sync birthday and life-expectancy details to remove the personal-profile payload from browser sync storage while keeping preference sync on.
• Turn off Sync preferences across devices to disable both scopes and remove both preference and personal payloads from browser sync storage.

Disabling sync does not delete the settings saved on your current device. A small configuration record indicating that sync is off may remain so other devices can respect that choice. For browser-managed records beyond these payloads, use your browser vendor’s sync-data controls.

Export and import

Settings → Data → Export downloads mortality-settings.json with your current Mortality settings. Import reads a settings file on your device and applies its recognized values to the local settings. The file is not uploaded to Mortality.

If browser sync is enabled when you import, fields covered by your enabled sync scopes are then mirrored through the browser vendor’s sync service.

Contact and support

For privacy questions or support, open an issue in the Mortality support tracker. Issues are public, so do not include your birthday or other personal information.

Mortality’s source code is public.