Note: From Firefox 45 onwards, when the browser crashes/restarts, the amount of data saved per origin is limited to 10MB.This has been done to avoid memory issues caused by excessive usage of web storage. Get Firefox, a free web browser backed by Mozilla, a non-profit dedicated to internet health and privacy. Available now on Windows, Mac, Linux, Android and iOS. The following screenshot (from Firefox for Android) provides an example: With the number input type, you can constrain the minimum and maximum values allowed by setting the min and max attributes. You can also use the step attribute to set the increment increase and decrease caused by pressing the spinner buttons. By default, the number input. HTML5 audio and video in Firefox Firefox handles many types of audio and video content on web pages. This article explains which media formats you can play and how to control, save, and open them. Mozilla Firefox up to 720p Opera up to 720p Safari up to 1080p on macOS 10.11 to 10.15. Safari up to 4K on macOS 11.0 or later.Streaming in 4K requires an HDCP 2.2 compliant connection to a 4K capable display, Intel's 7th generation Core CPU, and the latest Windows updates.
The Web Storage API provides mechanisms by which browsers can store key/value pairs, in a much more intuitive fashion than using cookies.
Web Storage concepts and usage
The two mechanisms within Web Storage are as follows:
sessionStoragemaintains a separate storage area for each given origin that's available for the duration of the page session (as long as the browser is open, including page reloads and restores)- Stores data only for a session, meaning that the data is stored until the browser (or tab) is closed.
- Data is never transferred to the server.
- Storage limit is larger than a cookie (at most 5MB).
localStoragedoes the same thing, but persists even when the browser is closed and reopened.- Stores data with no expiration date, and gets cleared only through JavaScript, or clearing the Browser cache / Locally Stored Data.
- Storage limit is the maximum amongst the three.
These mechanisms are available via the Window.sessionStorage and Window.localStorage properties (to be more precise, in supporting browsers the Window object implements the WindowLocalStorage and WindowSessionStorage objects, which the localStorage and sessionStorage properties hang off) — invoking one of these will create an instance of the Storage object, through which data items can be set, retrieved and removed. A different Storage object is used for the sessionStorage and localStorage for each origin — they function and are controlled separately.
Note: From Firefox 45 onwards, when the browser crashes/restarts, the amount of data saved per origin is limited to 10MB. This has been done to avoid memory issues caused by excessive usage of web storage.
Note: Access to Web Storage from third-party IFrames is denied if the user has disabled third-party cookies (Firefox implements this behavior from version 43 onwards.)
Note: Web Storage is not the same as mozStorage (Mozilla's XPCOM interfaces to SQLite) or the Session store API (an XPCOM storage utility for use by extensions).
Html5 Firefox Android
Web Storage interfaces
Storage- Allows you to set, retrieve and remove data for a specific domain and storage type (session or local.)
Window- The Web Storage API extends the
Windowobject with two new properties —Window.sessionStorageandWindow.localStorage— which provide access to the current domain's session and localStorageobjects respectively, and aWindow.onstorageevent handler that fires when a storage area changes (e.g. a new item is stored.) StorageEvent- The
storageevent is fired on a document'sWindowobject when a storage area changes.
Examples
To illustrate some typical web storage usage, we have created a simple example, imaginatively called Web Storage Demo. The landing page provides controls that can be used to customize the color, font and decorative image. When you choose different options, the page is instantly updated; in addition your choices are stored in localStorage, so that when you leave the page then load it again later on your choices are remembered.
In addition, we have provided an event output page — if you load this page in another tab, then make changes to your choices in the landing page, you'll see the updated storage information outputted as the StorageEvent is fired.
Specifications
| Specification | Status | Comment |
|---|---|---|
| HTML Living Standard | Living Standard |
Browser compatibility
Window.localStorage
BCD tables only load in the browser
Html5 Firefox Not Working
Window.sessionStorage
BCD tables only load in the browser
Private Browsing / Incognito modes
Most modern browsers support a privacy option called 'Incognito', 'Private Browsing' or something similar that doesn't store data like history and cookies. This is fundamentally incompatible with Web Storage for obvious reasons. As such, browser vendors are experimenting with different scenarios for how to deal with this incompatibility.
Most browsers have opted for a strategy where storage APIs are still available and seemingly fully functional, with the one big difference that all stored data is wiped after the browser is closed. For these browsers there are still different interpretations of what should be done with existing stored data (from a regular browsing session). Should it be available to read when in Private mode? Then there are some browsers, most notably Safari, that have opted for a solution where storage is available, but is empty and has a quota of 0 bytes assigned, effectively making it impossible to write data to it.
Developers should be aware of these different implementations and take them into account when developing websites depending on Web Storage APIs. For more information please have a look at this WHATWG blog post that specifically deals with this topic.
See also