Web Storage

Web storage lets a browser remember small bits of data.

localStorage keeps data until you clear it.

sessionStorage keeps data only for the current tab session.

localStorage

This is like a toy locker that stays locked overnight.

Close the browser. Open it later. The data can still be there.

sessionStorage

This is like a desk tray for today only.

Close the tab, and that tray is cleared.

setItem and getItem

Keys and values are stored as strings.

setItem saves. getItem reads.

removeItem and clear

removeItem deletes one key.

clear deletes everything in that storage.

Save objects with JSON

Storage only keeps strings.

Use JSON.stringify to pack an object. Use JSON.parse to unpack it.

Missing keys

If a key is not there, getItem returns null.

Check for null before you use the value.

Tip: Use localStorage for lasting settings. Use sessionStorage for short lived tab data.