Random Querystring to avoid IE caching

Question

It is a well known problem that IE caches too much of html, even when giving a Cache-Control: no-cache or Last-Modified header to everypage.

This behaiviour is really troubling when working with querystrings to get dynamic information, as IE considers it to be the same page (i.e.: http://example.com/?id=10) and serves the cached version.

I've solved it adding either a random number or a timestring to the querystring (as others have done) like this http://example.com/?id=10&t=2009-08-06_13:12:56 that I just ignore serverside.

Is there a better option? Is there another, cleaner way to acomplish this? I'm aware that POST isn't cached, but it is semanticaly correct to use GET here.

Your assertion is incorrect, by the way. IE doesn't "cache too much of HTML". See www.fiddler2.com/redir/?id=httpperf for discussion of caching in IE. — EricLaw, Apr 05 '10 at 21:38
@Eric, IE has some unexpected/inconsistent [behavior](http://support.microsoft.com/kb/222064/) [regarding caching](http://support.microsoft.com/kb/234067). — Esteban Küber, Apr 05 '10 at 21:55
using the generic $.ajax as suggested in the above post http://stackoverflow.com/a/1767342/5969842 helped solve the issue without using a random number — ravikumar, Feb 23 '16 at 17:00

Simon Fox · Answer 1 · 2009-11-20T02:00:40.640

11

Assuming you are using jQuery, instead of using $.get or $.getJson, use the more generic $.ajax and explicitly set the cache value to false. The following is an example:

$.ajax({
        url: "/Controller/Action",
        cache: false,
        type: "GET",
        dataType: "json",
        success: function(data, textStatus) {
                         alert("success");
                 }
    });

A little more code required (not much though) than using .getJson or .get but will solve the problem cleanly without appending random numbers.

edited Nov 20 '09 at 02:00

answered Nov 19 '09 at 23:31

Simon Fox

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i got to find that using GET request in IE we should set the not to cache the html and i set 'cache: false' and that prevented IE from bringing the result from cache..thanks – Lucky Jul 01 '13 at 06:53

score 6 · Answer 2 · answered Aug 05 '09 at 16:20

You could also use the current Unix Time in milliseconds to avoid the problem of many requests in one second (it is much less likely to have multiple requests in one millisecond)

var url = "http://whatever.com/stuff?key=value&ie=" + (new Date()).getTime();

score 2 · Answer 3 · answered Aug 05 '09 at 16:16

Using a random number (not timestamp) on the querystring, or actually changing the filename are the two methods recommended. Steve Souders and YAHOO!'s performance group has published a ton of useful information and practices they've discovered and developed while optimizing one of the world's most heavily-visited properties.

score 2 · Accepted Answer · edited May 23 '17 at 12:02

2

So, in the end, the only reliable way to do this (thanks to IE6) is using a random, or time bound querystring.

You could use a time bound querystring that only changes every 15 seconds (or any other amount of time), so you'd lower the server hit count, as you'd see locally cached content for those 15 seconds.

If you have a standard compliant browser, you can get away with only using ETags.

edited May 23 '17 at 12:02

Community

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answered Aug 23 '09 at 20:12

Esteban Küber

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This again will fail if the user comes back to the page using the back button and does a refresh on the page. Were you able to find a sure-shot solution which works in all cases? Thanks. – lostInTransit Sep 18 '09 at 14:02
You generate the "random" part of the querystring with javascript clientside like shown on http://stackoverflow.com/questions/1234246/random-querystring-to-avoid-ie-caching/1234260#1234260 That way, it will be different *every time* the `get` or `post` is done. – Esteban Küber Sep 18 '09 at 14:18
" ...(thanks to IE6) is ..." thanks to IE7 too, I did not test IE8 yet. – Marco Demaio Jun 08 '10 at 12:41

score 0 · Answer 5 · answered Aug 05 '09 at 16:16

0

I have the same problem, but take care, in one second there can be many requests. This is why I use this:

$.getJSON("http://server/example?param=value&dummy=" + Math.random(), ...);

answered Aug 05 '09 at 16:16

FWH

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Well, I don't want the **same client** hitting my server **several timer per second**, so I don't mind if the information showed is 1 second old. Of course, the output is plain text for humans. – Esteban Küber Aug 05 '09 at 16:18

score 0 · Answer 6 · answered Aug 05 '09 at 16:34

Have you tried adding an ETag header in the response? You might use a random one, or a checksum of the generated page so that the cached version is served when appropriate.

I'm not sure what's the behaviour of IE, but with recent versions it should work.

Random Querystring to avoid IE caching

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