- Fire Cookie
- Tamper Data
- Modify Headers
- Fire Cookie makes possible to view and manage cookies in your browser. Especially, you can modify and delete cookies.
- YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. YSlow is an extension to FireBug, and you need to install FireBug before installing YSlow. The YSlow grades your web application and provides recommendations to improve performance. Alternatively, you can also install Page Speed from Google. Similar to Yslow!, it tests website performance.
- Tamper Data is a fast, simple yet effective tool which can be used to do penetration testing. Use tamper data to view and modify HTTP/HTTPS headers, trace and time http response/requests and to security test web applications by modifying the POST parameters.
- Modify Headers is handy for modifying or adding new headers for testing purpose. For example, add SSO headers to test your application locally.
The FireBug has other developer productivity tools natively within Tools --> Web Developer
Native Inspect Element
This native "Inspect Element" from Firefox may look similar to “Inspect Element in Firebug”, but it acts in different ways. There is one distinctive feature known as the the 3D view, which analyses the web page in depth.
Responsive Design View
This native "Responsive Design View " assists with the Responsive Website Design (i.e. RWD). With more and more mobile users online via smartphones and tablets, it has never been more important to design a friendly environment for those visitors. A responsive website design allows your visitors to navigate to your site that is optimally designed for the device they are using like smartphone, tablet, or laptop/desktop, without having to painfully zoom in and zoom out.
If you work frequently with CSS then the "style editor" is very handy as it allows you to edit the CSS and see the impact of your change instantly. This is available from version 11.
Here are some step by step tutorials on using FireBug: