Are there any benefits to Session Storage over Local Storage?

Question

Apart from being non persistent and scoped only to the current window, are there any benefits (performance, data access, etc) to Session Storage over Local Storage?

Turkish

@robert - I believe you're incorrect. From w3.org/TR/webstorage sessionStorage is scoped to the "top-level browsing context", meaning it is unique to each browser tab / window. localStorage is scoped to the origin, however, meaning it's shared across all pages on the same origin. – Vertebral

Re: Performance jsperf.com/localstorage-vs-sessionstorage – Koy

Possible duplicate of What is the difference between localStorage, sessionStorage, session and cookies? – Credence

Answer 1

localStorage and sessionStorage both extend Storage. There is no difference between them except for the intended "non-persistence" of sessionStorage.

That is, the data stored in localStorage persists until explicitly deleted. Changes made are saved and available for all current and future visits to the site.

For sessionStorage, changes are only available per tab. Changes made are saved and available for the current page in that tab until it is closed. Once it is closed, the stored data is deleted.

Meli

there's a broader discussion that you may find helpful here: #19868099 – Spode

if you save some data in storage under http, you will not be able to retrieve it at https – Niall

i tested this on Chrome v41.x and it seems that the above statement about https is not true: localStorage retains its stored data. – Brain

SessionStorage survives over page reloads and restores, but opening a new tab/window will initiate a new session. – Promptitude

Answer 2

The only difference is that they have different expiration times.

• sessionStorage will only be accessible while and by the window that created it is open.

• localStorage lasts until you delete it or the user deletes it.

Let's say that you wanted to save a login username and password you would want to use sessionStorage over localStorage for security reasons (i.e. another person accessing their account at a later time).

But if you wanted to save a user's settings on their machine you would probably want localStorage.

In conclusion

• localStorage - use for long term use.
• sessionStorage - use when you need to store something that changes or something temporary

Blissful

Answer 3

Few other points which might be helpful to understand differences between local and session storage

1. Both local storage and session storage are scoped to document origin, so

   https://mydomain.example/ 
   http://mydomain.example/
   https://mydomain.example:8080/
   

   All of the above URL's will not share the same storage. (Notice path of the web page does not affect the web storage)

2. Session storage is different even for the document with same origin policy open in different tabs, so same web page open in two different tabs cannot share the same session storage.

3. Both local and session storage are also scoped by browser vendors. So storage data saved by IE cannot be read by Chrome or FF.

Hugh

No, same sessionStorage share between http and https but localStorage not. – Pfennig

If you set sessionStorage in https origin first, it will be available in http but if you create sessionStore in http then will not be available in http – Pfennig

@Shahdat, did you mean "then will not be available in https" (notice the s)? – Discordance

@DanielWerner yes, if you create sessionStore in http then will not be available in https. – Pfennig

Answer 4

The main difference between localStorage and sessionStorage is that sessionStorage is unique per tab. If you close the tab the sessionStorage gets deleted, localStorage does not. Also you cannot communicate between tabs :)

Another subtle difference is that for example on Safari (8.0.3) localStorage has a limit of 2551 k characters but sessionStorage has unlimited storage

On Chrome (v43) both localStorage and sessionStorage are limited to 5101 k characters (no difference between normal / incognito mode)

On Firefox both localStorage and sessionStorage are limited to 5120 k characters (no difference between normal / private mode )

No difference in speed whatsoever :)

There's also a problem with Mobile Safari and Mobile Chrome, Private Mode Safari & Chrome have a maximum space of 0KB

Porphyrin

limited to 5101 k characters? so.. 5.101 million characters? – Kipkipling

@Kipkipling Yes, 1 character is usually 1 byte hence 5 million characters is 5Mb worth of storage. – Freshwater

@BasimKhajwal That is 5MB. Bytes, not bits. – Dancer

Can you please add source to what you have mentioned? – Remanence

@Mukus, there is no source, I ran tests myself, and had an issue with Private Mode Safari for having localStorage but having no space there and my polyfill wouldn't trigger since localStorage existed, but the script failed since it couldn't store anything there. You can test too using this tool - dev-test.nemikor.com/web-storage/support-test – Porphyrin

Answer 5

sessionStorage is the same as localStorage, except that it stores the data for only one session, and it will be removed when the user closes the browser window that created it.

Darkish

Did you mean the tab instead of the window? – Wessel

The browser treats both tabs and windows the same way. – Darkish

Answer 6

• sessionStorage maintains 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)

• localStorage does the same thing, but persists even when the browser is closed and reopened.

I took this from Web Storage API

Kapp

Answer 7

performance wise, my (crude) measurements found no difference on 1000 writes and reads

security wise, intuitively it would seem the localStore might be shut down before the sessionStore, but have no concrete evidence - maybe someone else does?

functional wise, concur with digitalFresh above

Wilhelmina

regarding page load performance: Both, sessionStorage and localStorage are initiated and populated out of the page-load-render cycle. Therefore the toll on initial page load time is not measurable from within the browser. – Unlade

Answer 8

Ya session storage and local storage are same in behaviour except one that is local storage will store the data until and unless the user delete the cache and cookies and session storage data will retain in the system until we close the session i,e until we close the session storage created window.

Rebirth

Answer 9

The advantage of the session storage over local storage, in my opinion, is that it has unlimited capacity in Firefox, and won't persist longer than the session. (Of course it depends on what your goal is.)

Rude

Answer 10

Late answer but felt to add some points here.

Session storage will be available for specific tab where as we can use Local storage through out the browser. Both are default to same origin and we can also store values manually with key, value pairs (value must be string).

Once tab (session) of the browser is closed then Session storage will be cleared on that tab, where as in case of Local storage we need to clear it explicitly. Maximum storage limit respectively 5MB and 10MB.

We can save and retrieve the data like below,

To Save:

sessionStorage.setItem('id', noOfClicks);   // localStorage.setItem('id', noOfClicks);

sessionStorage.setItem('userDetails', JSON.stringify(userDetails));   // if it's object

To Get:

sessionStorage.getItem('id');    // localStorage.getItem('id');

User user = JSON.parse(sessionStorage.getItem("userDetails")) as User;  // if it's object

To Modify:

sessionStorage.removeItem('id');    // localStorage.removeItem('id');

sessionStorage.clear();   // localStorage.clear();

P.S: getItem() also return back the data as string and we need convert it into JSON format to access if it's object.

You can read more about Browser Storages here..

1. Difference between localStorage, sessionStorage and cookies

2. localstorage-vs-sessionstorage

Daily

Answer 11

Local storage: It keeps store the user information data without expiration date this data will not be deleted when user closed the browser windows it will be available for day, week, month and year.

//Set the value in a local storage object
localStorage.setItem('name', myName);

//Get the value from storage object
localStorage.getItem('name');

//Delete the value from local storage object
localStorage.removeItem(name);//Delete specifice obeject from local storege
localStorage.clear();//Delete all from local storege

Session Storage: It is same like local storage date except it will delete all windows when browser windows closed by a web user.

//set the value to a object in session storege
sessionStorage.myNameInSession = "Krishna";

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Quintinquintina