What are different aspects of Cross Browser Testing?

Cross browser can be defined as the ability of a web page, web site or web application to run easily on all the browsers i.e., the web site, web page or application should have a good browser compatibility.

Many people confuse between cross browser compatibility and multiple browser compatibility.

Multiple browser compatibility is the ability of a web site, web page or application to execute efficiently on many browsers simultaneously. If a web site, web page, or application is having good browser compatibility, it is able to run on all browsers and without any loss of performance.

Maintenance of standards of performance is essentially necessary. All the browsers are then able to render that particular web site or application.

1. Cross browser testing is a no new methodology and has been in use since the web development started.
2. But, nowadays cross browser testing is used rarely since the modern versions of the browsers already have built in support for scripts like CSS 1 and HTML and so the browsers do not require any kind of proprietary extensions to attain the quality of cross browsing.
3. Another reason is that nowadays DOM manipulation methodologies which are way more compatible than cross browser compatibility testing are being used for the development of client side scripts.
4. The main browsers that a web page, site, application or a script needs to support include the following:

- Internet explorer
- Netscape
- Mozilla Firefox
- Google chrome
- Safari and
- Opera

These days only a little of cross browser support is demanded. The emphasis is on improving compatibility. The World Wide Web consortium introduced in 1997 a browser scripting language called “ECMA script” which was supposed to improve the cross browser compatibility of the browsers. It was after this only that the W3C started working up on DOM techniques.

1. Cross browser testing forms an essential part of web testing or when application testing, so it needs to be focused up on.
2. There are several testing tools available in the market today to carry out automated cross browser testing.
3. There are so many web browsers available today, and so the end users are not using the same browser.
4. A variety of browsers are in user which calls a need for testing of web sites and applications.
5. This need can be fulfilled by cross browser testing.
6. Client components like applets, flex, flash programs, AJAX and java scripts may behave differently when accessed through different browsers.
7. Also for every browsers hands end user’s request in a way that is different from the other.
8. Web developers need to make sure that the web sites and applications they are making are compatible with all the browsers and deliver exactly the same performance on any browser.
9. Testing a website or application for a single browser is of course not beneficial.
10. Cross browser testing involves testing of web sites or applications on both the sides i.e., client side and server side.

There are following kinds of engines:
- Gecko is used in Mozilla Firefox browser.
- KHTML is used by conqueror web browser.
- Presto is developed by opera and is used for opera browser.
- Trident or MSHTML is used for Microsoft developed browser “internet explorer”.
- Web kit is used for Google chrome and safari. It supports other browsers also.

Layout engines play a very important role in cross browser testing. They are basic entity that needs to be tested when you want to improve the cross browser compatibility. A layout engine is a web component that takes web contents and formatting instructions as input and displays the formatted content on the web page.