Transparent background slows browser




14 years ago
13 years ago


(Reporter: uruviel, Assigned: pavlov)


Windows XP

Firefox Tracking Flags

(Not tracked)





14 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b) Gecko/20050122 Firefox/1.0+
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b) Gecko/20050122 Firefox/1.0+

Using a transparent gif or png as background (specified in the CSS) on any
element. Slows the painting and overall performance of the browser.
I've seen this happen on and . And numerous other sites that rely on transparency.
(note: the preformance of IE or Opera is not affected by this)

Reproducible: Always

Steps to Reproduce:
1. open a site with a transparent background

Actual Results:  
Slow performance

Expected Results:  
Normal performance

Comment 1

14 years ago
Sorry seems not affected (anymore) by this problem.

Comment 2

14 years ago
Is this bug different from the bug 279250 you reported in any way?

Comment 3

14 years ago
The sites that you provided seem to work fine, and I haven't encountered any
problem with PNG images, but I have experience massive slowdowns with
transparent GIFs, whether they are simply used as images or background images. I
have posted a bugzilla entry 293222 for this problem.
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Last Resolved: 13 years ago
Resolution: --- → EXPIRED
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