Why is IETESTER different from my local one_html/css_WEB-ITnose

Use IETESTER to test a piece of code:

<div style="background:red;   width:100px; height:100px; float:left"></div><div style="background:green; width:100px; height:100px;"></div><div style="background:blue;  width:100px; height:100px;"></div>

IETERSTER’s IE8:


The native IE8:


Why is it the same IE8, but the results are different? Are the results from IETESTER trustworthy?

Reply to discussion (solution)

ie collection is more accurate than ietester

ie collection is more accurate than ietester To be more precise
I mean there might be something wrong with IETESTER, right?

Take a look at Baidu. . . .

Quoting the reply from acesidonu on the 1st floor:

IE collection is more accurate than IETESTER

Does it mean IETESTER may have problems?
Sometimes it is inaccurate

ietester can only be used as a reference, and the native IE shall prevail

Well, thank you everyone!