Compatibility issues JavaScript

unload event behavior differences between browsers

Safari and IE fire the unload event whenever you click a link to leave a page or even just close a window or tab with the page. Opera and Firefox let you click the window’s close button without firing the unload event.

Compatibility issues JavaScript

Browser resize event behavior in firefox

Firefox fires this event only once, once the user has let go of the resize bar. All other browsers fire this multiple times as the user resizes a window ( IE, Opera, Safari ).


DOM (Document Object Model)

It is an abstract, internal representation browsers keep of the page loaded, with all the elements integrating it and the order they were loaded, so it is disposable to JavaScript for further manipulation. It is a convention of the World Wide Web Consortium (W3C) that browsers follow.

Compatibility issues CSS

Browsers: Firefox problems and browser compatibility issues with Firefox

  1. You want Firefox scroll bars always (to avoid content shifting)
    • CSS html {
Compatibility issues HTML

CSS Browser conditionals for IE

Example of how IE support conditionals that narrow the code to only a specific browser and version:

<!–[if gte IE 5]> <style type=”text/css”>

 Your code here


Compatibility issues HTML HTML5

Making IE6+ browser render as other browser engines

In quirks mode, it acts like IE 5.

Implements most of CSS 2.1 goodness.

To turn off compatibility mode and revert it back to IE 7 behavior, put the following tag in the head:

<meta http-equiv=”X-UA-Compatible” content=”IE=edge” />

Now, if you want a really good HTML5 ready engine to run on your old IE browsers, put the following tag:

<meta http-equiv="X-UA-Compatible" content="chrome=1" />
That will render pages as in chrome, even as you hit them with IE.