Privacy
Short version: your workbooks stay on your device. There are no accounts, no adverts, no analytics and no tracking.
Last updated 24 October 2026
What is stored, and where
Neon Sparks Sheets runs entirely in your web browser. Everything it keeps is stored by your browser, on your device, for this website only:
- Your workbooks, saved automatically as you work (IndexedDB), including any pictures you insert into them.
- Earlier versions of your workbooks (File › Version history), kept in the same place so you can go back. The newest 30 versions of each workbook are kept, and they are deleted with the workbook.
- Your settings, such as the theme, how dates are typed, the status-bar figures you chose and the symbols you used recently (localStorage).
- Your name for notes and comments, if you enter one (you’re asked the first time you add a comment, and can change it in File › Options). It is kept only in this browser and is written into the notes and comments you add, so it travels with a workbook you save or share.
- The app itself, so it works offline (the browser’s cache, through a service worker).
We cannot see any of this. To delete a workbook, use the bin button next to it in File › Recent, or clear this site’s data in your browser settings. Clearing site data deletes your stored workbooks for good, so keep a backup (File › Download a backup) of anything important. A backup is a file you download to your own device, of one workbook or of every workbook in this browser; File › Open a backup reads it back. It isn’t sent anywhere.
What is never sent anywhere
Your workbooks and their contents are never uploaded to us or to anyone else. Opening a file, saving a file, printing, making a PDF and keeping versions all happen on your device. Passwords for protected files are used only to open or save that file and are never stored. Copying and pasting only uses your device’s clipboard. The website does not set cookies.
Hosting
Like any website, the web server that delivers the app to you handles your IP address and normal request details (such as the page requested and your browser type) in order to send the pages, and the hosting provider may keep short-term server logs for security. These logs are not used to identify or track you.
Contact
Questions about privacy? Message @NeonSparksUK on X.