How much data can a browser save in localStorage

Question

Thanks for the answer allaire. To get an exact answer I ended up writing a script. The ballpark results are that you get a minimum of 5MB on desktop webkit, ff, ie, opera. IE actually let me write 1GB, yes 1 GB of data.

Oddly, ff crashed when trying to write a string with a length of 742 characters but it would write a string of length 1133 characters and this was with the cache cleared so I don’t know what’s up with that.

~1000 character object written to different localStorage[locations]

How big of a string can a given localStorage location be?

This is a messy script but you can run the tests yourself if you want:

<!DOCTYPE />
<html>
<script src="http://code.jquery.com/jquery-1.6.4.min.js"></script>
<script type="text/javascript">
    $(document).ready(function () {
        var alphabet = "abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 123456789 {} +-=*/\'[]<>|&^%$#@!,?.";
        var i = 0;
        var curWord = "";
        var tot = 0;
        localStorage["sameSpot"] = null;
        $("#same").bind("click", function () {
            var write = function () {
                if (!localStorage["sameSpot"])
                    localStorage["sameSpot"] = alphabet[i++];
                else {
                    curWord = alphabet[i++] + localStorage["sameSpot"];
                    localStorage["sameSpot"] = curWord;
                }
                if (i == alphabet.length)
                    i = 0;
                tot++;
                $("#local").html(curWord);
                $("#memory").html(localStorage["sameSpot"]);
                $("p").html("The number of characters written to localStorage[\"sameSpot\"] is: " + tot);
                setTimeout(write, 1);
            };
            write();
        });


        var tot2 = 0;
        var totChars = 0;
        $("#different").bind("click", function () {
            var write = function () {
                var saveObj = {
                    alphabet: alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet + alphabet,
                    date: new Date(),
                    random: Math.random()
                };
                saveObj = JSON.stringify(saveObj);
                totChars += saveObj.length;
                localStorage["t" + tot2] = saveObj;
                $("#local").html(saveObj);
                $("#memory").html(localStorage["t" + tot2]);
                tot2++;
                $("p").html("The number of unique entries made in localStorage[0++] is " + tot2 + " and the total number of characters is: " + totChars + " with an average of " + Math.floor(totChars / tot2) + " characters per record");
                setTimeout(write, 1);
            };
            write();
        });
    });
</script>
<body>
<button id="same">Write Chars To Same Spot</button>
<button id="different">Write Chars To Same Spot</button>
<br />
<p></p>

<textarea rows="50" cols="100" id="memory"></textarea>
<textarea rows="50" cols="100" id="local"></textarea>
</body>
</html>

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