Get HTML5 localStorage keys

Question

I'm just wondering how to get all key values in localStorage.

---

I have tried to retrieve the values with a simple JavaScript loop

for (var i=1; i <= localStorage.length; i++)  {
   alert(localStorage.getItem(i))
}

But it works only if the keys are progressive numbers, starting at 1.

---

How do I get all the keys, in order to display all available data?

Answer 1

for (var key in localStorage){
   console.log(key)
}

EDIT: this answer is getting a lot of upvotes, so I guess it's a common question. I feel like I owe it to anyone who might stumble on my answer and think that it's "right" just because it was accepted to make an update. Truth is, the example above isn't really the right way to do this. The best and safest way is to do it like this:

for ( var i = 0, len = localStorage.length; i < len; ++i ) {
  console.log( localStorage.getItem( localStorage.key( i ) ) );
}

Answer 2

in ES2017 you can use:

Object.entries(localStorage)

Answer 3

I like to create an easily visible object out of it like this.

Object.keys(localStorage).reduce(function(obj, str) { 
    obj[str] = localStorage.getItem(str); 
    return obj
}, {});

I do a similar thing with cookies as well.

document.cookie.split(';').reduce(function(obj, str){ 
    var s = str.split('='); 
    obj[s[0].trim()] = s[1];
    return obj;
}, {});

Answer 4

function listAllItems(){  
    for (i=0; i<localStorage.length; i++)  
    {  
        key = localStorage.key(i);  
        alert(localStorage.getItem(key));
    }  
}

Answer 5

You can get keys and values like this:

for (let [key, value] of Object.entries(localStorage)) {
  console.log(`${key}: ${value}`);
}

Answer 6

You can use the localStorage.key(index) function to return the string representation, where index is the nth object you want to retrieve.

Answer 7

If the browser supports HTML5 LocalStorage it should also implement Array.prototype.map, enabling this:

Array.apply(0, new Array(localStorage.length)).map(function (o, i) {
    return localStorage.key(i);
})

Answer 8

Since the question mentioned finding the keys, I figured I'd mention that to show every key and value pair, you could do it like this (based on Kevin's answer):

for ( var i = 0, len = localStorage.length; i < len; ++i ) {
  console.log( localStorage.key( i ) + ": " + localStorage.getItem( localStorage.key( i ) ) );
}

This will log the data in the format "key: value"

(Kevin: feel free to just take this info into the your answer if you want!)

Answer 9

This will print all the keys and values on localStorage:

ES6:

for (let i=0; i< localStorage.length; i++) {
    let key = localStorage.key(i);
    let value = localStorage[key];
    console.log(`localStorage ${key}:  ${value}`);
}

Answer 10

For anyone searching this trying to find localStorage keys...

The answer is simply:

Object.keys(localStorage);

Answer 11

I agree with Kevin he has the best answer but sometimes when you have different keys in your local storage with the same values for example you want your public users to see how many times they have added their items into their baskets you need to show them the number of times as well then you ca use this:

var set = localStorage.setItem('key', 'value');
var element = document.getElementById('tagId');

for ( var i = 0, len = localStorage.length; i < len; ++i ) {
  element.innerHTML =  localStorage.getItem(localStorage.key(i)) + localStorage.key(i).length;
}

Answer 12

You can create an object even more simply by using Object.assign:

// returns an object of all keys/values in localStorage
Object.assign({}, window.localStorage);

You can read more about it here at MDN.

The caniuse page says support is currently at about 95% of all browser share (IE being the odd one out-- what a surprise).

Answer 13

For anyone looking for a jQuery solution, here is a quick example.

$.each(localStorage, function(key, str){
  console.log(key + ": " + str);
});

Answer 14

For those mentioning using Object.keys(localStorage)... don't because it won't work in Firefox (ironically because Firefox is faithful to the spec). Consider this:

localStorage.setItem("key", "value1")
localStorage.setItem("key2", "value2")
localStorage.setItem("getItem", "value3")
localStorage.setItem("setItem", "value4")

Because key, getItem and setItem are prototypal methods Object.keys(localStorage) will only return ["key2"].

You are best to do something like this:

let t = [];
for (let i = 0; i < localStorage.length; i++) {
  t.push(localStorage.key(i));
}

Answer 15

Just type localStorage to developer console. It logs localStorage keys nicely formatted. Sometimes the easiest answer is the best one :)