Points to be considered while Cross Browser Compatibility Testing and Checklist
Cross-browser testing is essential for ensuring application compatibility with a wide variety of Web browsers. Ideally, cross-browser testing should involve multiple computers with various combinations of operating systems. This also includes the need to centrally organize simultaneous or sequential test execution across multiple computers.
There are many elements that will not change across browsers (like images size, fonts colour, texts padding and pages background). However, there are many other elements that will need more attention as follows:
Font size and font style: some browsers overwrite these properties.
Special characters with HTML character encoding.
Controls alignment: bullets, radio buttons and checkboxes might not be correctly aligned.
Information submitted to the database: if there are forms that interact with the database, it is necessary to verify that the information is correctly stored.
HTML5 video format: users must be aware that depending on the player or plugin used, not all the browsers are able to play all the existing video formats. For example, Internet Explorer 9 will only play .mp4 videos and Firefox 9 will allow only .webm videos while Chrome will be more flexible (.mp4, .webm, .ogv and other video formats).
Text alignment: some dropdown items will look good in Internet Explorer while in Safari they might appear too close to the upper margin.
Plugins developed by external sites: some jQuery plugins might not work correctly, like print functionalities in IE8 or carousel rotation when playing videos.
CMS compatibility: be sure to know the browsers that the Content Management System supports and focus mostly on that browser versus other ones.
These are the issues that should be taken care of by the development team and the QA team. I am herewith attaching Cross Browser Compatibility Testing checklist too.