| Cache | Server/CDN | Temporary (depends on config) | Large | ✅ | ❌ | API responses, rendered pages, assets |
| locals (SvelteKit) | Server (per request) | Request-scoped | Small | ✅ | ❌ | Passing auth data or DB connections across requests |
| localStorage | Browser (client) | Permanent (until cleared) | ~5MB | ❌ | ❌ | Saving user settings, theme, or state that should persist |
| sessionStorage | Browser (client) | Cleared when tab is closed | ~5MB | ❌ | ❌ | Temporary data that only matters while the page is open |
| Cookies | Browser & Server | Configurable (Session or Expiry) | ~4KB | ✅ | ❌ | Authentication tokens, remembering logged-in users |
| Svelte Stores | Client (RAM) | Lost on refresh | No limit (memory-based) | ❌ | ✅ | UI state, form data, reactivity |