Some websites have the ability to store information, such as files, in your local storage, and these files can only be removed manually by you. This helps the website run faster and prevents information from being lost if you lose your connection. This feature is enabled by [https://developer.mozilla.org/docs/Web/API/Web_Storage_API storage API]. When a website has storage API, Firefox will first ask you for permission to let a website add files to your local storage. When the prompt appears in your address bar, choose “Allow” or “Don’t Allow”. ;[[Image:notification storage api]] =What if my storage is full?= You’ll see a prompt at the top of the page letting you know that your storage is full. Click the {for win}{button Options}{/for}{for mac,linux}{button Preferences}{/for} button to manage your storage. Freeing up space on your disk by deleting files can also free up storage for Firefox. ;[[Image:notification bar storage api]] <!-- The setting to turn off the feature doesn't exist in Fx57 and doesn't work in fx56 or below. Also, "Clear all Data" in Fx57 removes all cookies. (see discusson). =I want to modify or turn off this setting= {for not fx57} #[[T:optionspreferences]] #Click the {for not fx56}{menu [[Advanced panel - Accessibility, browsing, network, updates, and other advanced settings in Firefox|Advanced]]} panel on the left, then click on the {menu Network} tab.{/for}{for =fx56}{menu Privacy & Security} panel on the left, then go down to the ''Security'' section.{/for} # Under the ''Offline Web Content and User Data'' section, remove the checkmark from the box in front of '''Tell you when a website asks to store data for offline use'''. You can also clear all the saved data by clicking {button Clear Now}. {/for} {for fx57} #[[T:optionspreferences]] #Click the {menu Privacy & Security} panel on the left. # Under ''Site Data'', click {button Settings} to change your site storage API settings. You can also clear all the saved data by clicking {button Clear all Data}. {/for} -->

Some websites have the ability to store information, such as files, in your local storage, and these files can only be removed manually by you. This helps the website run faster and prevents information from being lost if you lose your connection. This feature is enabled by storage API.

When a website has storage API, Firefox will first ask you for permission to let a website add files to your local storage.

When the prompt appears in your address bar, choose “Allow” or “Don’t Allow”.

What if my storage is full?

You’ll see a prompt at the top of the page letting you know that your storage is full. Click the OptionsPreferences button to manage your storage. Freeing up space on your disk by deleting files can also free up storage for Firefox.