[whatwg] The sizes="" attribute for rel=icon

Kornel Lesinski kornel at osiolki.net
Wed May 28 12:10:25 PDT 2008

On Wed, 28 May 2008 13:07:50 +0100, Ian Hickson <ian at hixie.ch> wrote:

>> I'm afraid that this could cause trouble (every visitor downloading icon
>> that's 20–300 times larger than typical favicon). Why not use
>> rel=application-icon or rel=appicon?
> I don't understand the question.

<link rel=icon> is currently used for favicons. Favicons are expected to  
be small (in byte size). Current browsers always download favicons on  
every website.

If page author adds high-quality image using rel=icon (like Vista's 100KB  
icon or Leopard's 300KB monstrosity), it may significantly increase site's  
traffic (these icons will be downloaded by every visitor rather than only  
those who create a shortcut).

<link rel=icon sizes=16x16 href=tinyicon.png>
<link rel=icon sizes=256x256 href=hugeicon.ico>

In current browsers this will not work as expected - browsers will  
download the big application icon, which is going to be order of magnitude  
larger (in byte size) than a favicon.

Using rel=application-icon instead of rel=icon would avoid this problem.  
Another solution would be to suggest that authors specify favicon as last  
in the tree order (example it the spec lists favicon first).

regards, Kornel Lesiński

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