The durability read-only property of the IDBTransaction interface returns the durability hint the transaction was created with. This is a hint to the user agent of whether to prioritize performance or durability when committing the transaction.

The value of this property is defined in the options parameter when creating a transaction using IDBDatabase.transaction().

Any of the following literal strings:

"strict"

The user agent may consider that the transaction has successfully committed only after verifying that all outstanding changes have been successfully written to a persistent storage medium.

"relaxed"

The user agent may consider that the transaction has successfully committed as soon as all outstanding changes have been written to the operating system, without subsequent verification.

"default"

The user agent should use its default durability behavior for the storage bucket. This is the default for transactions if not otherwise specified.

For a full working example, see our To-do Notifications app (view example live).