Why quirks mode ie

TomMcDonald - quirks mode is still listed in IE11 dev tools, but is referred to simply as "5" in the list of IE versions that can be emulated. However, it is only in IE11; it is not present in the Edge browser that replaces IE, so if you're using that, you won't see any reference to quirks mode, nor indeed to any other emulation mode for old IE version.

So, for example, if you want to emulate Internet Explorer 8. Thanks for this answer! It helped me to fix a problem where the HTML page that I was trying to load in a web browser control wouldn't load correctly. Apparently, it must have been because the HTML 5 document was not correctly interpreted by the instance of IE that the web browser control was using internally.

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Question feed. Stack Overflow works best with JavaScript enabled. Note that your page does not have to validate according to the chosen doctype, the mere presence of the doctype tag is enough to trigger strict mode. On this site I use this doctype in most pages. But the browser vendors were not to be denied: browser after browser implemented doctype switching, and nowadays all modern browsers support it.

Nonetheless browser vendors, Mozilla especially, thought this was such a confusing situation that they introduced "almost strict mode". This was defined as strict mode, but with images continuing to be blocks, and not inline elements.

Most common doctypes, including the one I use, trigger almost strict mode. The treatment of images is by far the most important difference between almost strict mode and really strict mode. In IE 6 Windows, Microsoft implemented one extra rule: if a doctype that triggers strict mode is preceded by an xml prolog, the page shows in quirks mode. This was done to allow web developers to achieve valid pages which require a doctype but nonetheless stay in quirks mode.

This is the xml prolog. You should put it on the very first line of your document, before the doctype. What, exactly, are the differences between the two modes? There are a few more differences that can trip up the unwary web developer. The table below summarizes a few of the most important ones. IE6, 7 and 8 all switch back to 5. Standard : There are two box models , the traditional and the W3C. Obviously, the W3C one, where the width excludes padding and borders, is the standard.

In IE, the rendering mode decides which box model it follows. There are some descriptions, such as The effects of quirks mode emulation about IE, by Microsoft, but such descriptions cover some aspects only. This may mean just about anything. When creating a a new page , you need not know about Quirks Mode and should usually not think about it. The list is most probably not exhaustive. It relates mainly to IE 7. Other browsers may have a Quirks Mode that does simulate old versions of IE to the same extent.

The following simple images demonstrate one of the many differences between Quirks Mode and Standards Mode on Internet Explorer, namely the box model. In Standards Mode, it specifies the width of the content of the element, so that the total width of the box 12em plus the widths of the borders. On Firefox, the correct box model is applied in both modes. A form that should have yellow background. If the form has a border set for it, it may be drawn incorrectly, excluding some part of the form.

There is a simple separate test page for this IE 7 bug.