IndexedDB
Also known as: IDB, browser database, offline web database
IndexedDB is a structured, in-browser database that web apps use to store larger amounts of data on your device — offline content, cached records, and full app state. It can grow much larger than cookies or localStorage, and clearing a site’s data is how you reclaim it.
- A structured database for web apps in the browser
- Can hold far more than cookies or localStorage
- Cleared with a site’s data; resets offline state
A real database in the browser
Where localStorage handles a few small keys, IndexedDB stores structured records that web apps can query — making it the backbone of email, notes, maps, and other apps that work offline. A single web app can keep hundreds of megabytes here.
This is why a browser can quietly hold a lot of space: rich web apps stash documents, images, and search indexes in IndexedDB so they load instantly and run without a connection.
Clearing IndexedDB
IndexedDB is part of a site’s data. In Chrome, clear it through Settings > Privacy and security > Delete browsing data > Cookies and other site data, or per site under Privacy and security > Site settings. On iOS, clearing Safari or a browser app’s website data removes it.
Clearing it forces the web app to re-download or rebuild its data, and can sign you out or reset offline content — so it frees real space but resets that app’s state.