Web Developer tool, is the add-on for your firefox, chrome, seamonkey browsers. It gives you extra tools to debug your website, HTML, layout, javascript and even images. It lets you control your browser’s cache and cookies etc. as well. Following is a quick overview of how this can be useful to you:

Disable

Cookies

CSS

Forms

Images

Information

Miscellaneous

Outline

Resize

Tools

View Source

Options

Installation

1. Choose your browser, compatible browsers are firefox, chrome and seamonkey. 2. Follow the link Web Developer Tools  3. Click the button “Download Now” and it will download and install for your browser. You need to restart your browser to make it work. Special thanks to developer of this tool.