Your browser only. All events are saved in your browser's localStorage — the same place websites store your preferences.
Nothing is sent anywhere. This is a static page — it is served from a web server, but your data never leaves your browser. No database, no backend, no tracking.
You are in control. Use the Export button to download a JSON backup. Use Import to restore it later.
Warning: Clearing your browser data (cookies, cache) or using private/incognito mode will delete your events. Export regularly!