Cookies and browser storage serve different purposes. Cookies can be attached to website requests; local storage holds study data and preferences in your browser. Silacademic does not install advertising trackers. Cloudflare Web Analytics measures page usage and performance; according to Cloudflare, this measurement does not use cookies or local storage.
First-party sign-in storage
| Cookie | Purpose | Maximum lifetime |
|---|---|---|
| __Host-silacademic | Authenticated sign-in session | 7 days; revoked by sign-out |
| __Host-silacademic-device | Recognise a registered browser for the two-device limit | 1 year in the browser; server registration persists until removed |
| __Host-google-state | Protect Google sign-in against a mismatched request | 10 minutes |
| __Host-silacademic-pending | Allow device replacement after a verified sign-in | 10 minutes |
These cookies support authentication and security. They are not advertising cookies. Blocking them can prevent sign-in or cause the browser to be treated as a new device. Hosting and checkout providers may additionally use storage for security and their own requested services.
Your local study workspace
Local storage holds your personal notebook, progress, material annotations, plans and preferences, including entries whose names start with ac: and reading preferences such as ra_voice and ra_rate. This storage does not have a fixed expiry. It remains until you or your browser remove it, except that signing out removes synchronised study data already saved in your account. While you are signed in, progress (completed items with their dates and tick/untick times), week notes, calendar events, timetable, material annotations and handwriting, the personal notebook, and Google Calendar/Tasks connection switches are also synchronised to your account; entries starting with ac:sync: record what was last synchronised. Study plans and preferences are not copied to another browser.
Dated lesson notebooks opened from the timetable are saved separately to your account. Draft entries beginning with silacademic-note: help recover unsaved changes on this device and are removed after a successful save or explicit discard. Clearing browser storage can remove these drafts but does not delete notes already saved to your account. Downloaded backups are files on your device; the lesson notebook offers a backup import control.
Third-party services
Google sign-in, optional Calendar/Tasks connections, YouTube lesson players and Paddle checkout can involve their own requests and storage. A video player is loaded when you open its video resource; the privacy-enhanced player is not a promise that no information reaches YouTube. Paddle checkout loads when you start payment. Their notices are linked in our Privacy notice.
Your controls
You can inspect or delete cookies and site data in your browser settings. Save important notes before clearing local storage: changes that have not synchronised yet, for example ones made offline, exist only in that browser until they upload. Sign out to revoke the current session and use My devices to remove a registered browser. Clearing cookies alone does not remove its server registration. Revoking Google permissions does not cancel a Paddle subscription; manage billing separately.