PNG transparency fix for IE6
While we try to avoid using transparent images (using png format) as much as we can because IE6 cannot handle it very well, there are times when we just can’t avoid it. (As much as we wish all IE6 users would change to a better browsers, that doesn’t seem to happen soon and it is our job to make sure our websites are cross-browser compatible)
We have been using the well known twinhelix for a while and it works wonder for us. However, recently it came to our attention that this png fix seriously eats up server’s resources and can even get IE6 users temporarily banned from the site, our client reported that:
“We have one kind of troubling thing that happens almost once a day, a customer will try to view the site and will receive an error and in the logs it shows HUNDREDS of requests for blank.gif, this causes the server to ban them permanently as it thinks there is a DDos attack. It seems to be only happening to customers using early versions of IE6…any idea about this one? I read somewhere about problems like this occurring due to iepngfix.htc”
So we did a research and found out that this issue is valid. Note that, on the reported site we were using version 1.0 of this png fix (2.x now available on their site) so we don’t know if upgrading will fix the problem. We did not upgrade because we found a better solution for png transparency problem which is very lightweight (only 2kb) and way faster. The only drawback is that your IE6 users MUST have javascript enabled to make sure this fix work for them (Worry not, most users who are stuck with IE6 don’t know/care to disable javascript anyway)
Hopefully the script we have just found will also help you as well
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I’ve been using google code’s IE fix for transparencies and a few other things…
http://code.google.com/p/ie7-js/
What’s your take on this versus the Unit fix?
Hi Emiliano,
Thanks for sharing the info, I bet readers of this blog will find it valuable and helpful. I myself have never used the module you are using, but I don’t think we are going to use it in any near future project for some reasons:
1. It’s huge (30-40KB) while Unit PNG fix is just about 2KB. I haven’t had the chance to do performance test for these 2 modules though, but I think I will do soon.
2. It doesn’t solve the background attribute issue anyway (Unit PNG fix kinda handles it, tho not quite well)
3. It claims to “make Microsoft Internet Explorer behave like a standards-compliant browser”, but we haven’t found the need to do this in our designs. We managed to get around certain IE issues such as the margin/padding issue of IE6 by using different coding techniques to avoid this issue. In short, it may provide more features than we actually need (and as coders, we know that more features = more performance penalties)
Good to know, I’m going to check out your new solution right now.