How to force a favicon refresh

favicon

I have a Grails application running locally using its own tomcat and I have just changed the favicon for a new one. Problem is that I can not see it in any browser. The old favicon shows up or I get no favicon at all, but not my new one. I do not think this is a Grails issue per se, more an issue with favicons.

What is supposed to happen with favicons? How are they supposed to work? I have numerous bookmarks in my browser which have the wrong icons and they never seem to get refreshed. How do I force the server/browser to stop caching them? It seems pretty silly to always cache them given they are normally only 16×16. Why not just upload them with every visit to the page? It is not exactly a huge overhead.

Best Answer

To refresh your site's favicon you can force browsers to download a new version using the link tag and a query string on your filename.
This is especially helpful in production environments to make sure your users get the update.

<link rel="icon" href="http://www.yoursite.com/favicon.ico?v=2" />

Related Solutions

Javascript – Changing website favicon dynamically

Why not?

var link = document.querySelector("link[rel~='icon']");
if (!link) {
    link = document.createElement('link');
    link.rel = 'icon';
    document.getElementsByTagName('head')[0].appendChild(link);
}
link.href = 'https://stackoverflow.com/favicon.ico';

How to prevent favicon.ico requests

I will first say that having a favicon in a Web page is a good thing (normally).

However it is not always desired and sometime developers need a way to avoid the extra payload. For example an IFRAME would request a favicon without showing it. Worst yet, in Chrome and Android an IFRAME will generate 3 requests for favicons:

"GET /favicon.ico HTTP/1.1" 404 183
"GET /apple-touch-icon-precomposed.png HTTP/1.1" 404 197
"GET /apple-touch-icon.png HTTP/1.1" 404 189

The following uses data URI and can be used to avoid fake favicon requests:

<link rel="shortcut icon" href="data:image/x-icon;," type="image/x-icon">

For references see here:

UPDATE 1:

From the comments (jpic) it looks like Firefox >= 25 doesn't like the above syntax anymore. I tested on Firefox 27 and it doesn't work while it still work on Webkit/Chrome.

So here is the new one that should cover all recent browsers. I tested Safari, Chrome and Firefox:

<link rel="icon" href="data:;base64,=">

I left out the "shortcut" name from the "rel" attribute value since that's only for older IE and versions of IE < 8 doesn't like dataURIs either. Not tested on IE8.

UPDATE 2:

If you need your document to validate against HTML5 use this instead:

<link rel="icon" href="data:;base64,iVBORw0KGgo=">

Best Answer

Related Solutions

Javascript – Changing website favicon dynamically

How to prevent favicon.ico requests

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