• Auto complete address in the address bar: Instead of typing http:// prefix and .com, .net, or .org suffix in the Firefox address bar, you can just type the name of the website like slashdot and press CTRL+SHIFT+Enter to automatically append .org, and add http:// prefix to the URL name. Similarly, CTRL+Enter for .com and SHIFT+Enter for .net domain names. e.g.: type google and press CTRL+Enter to automatically convert google to http://google.com
  
  
• Sometimes if you mistakenly type some URL in the browser, or open some link, it would show up in the address bar, because of the auto completion feature. No, I am not talking about Porn sites, for which its always better to start private browsing by pressing CTRL+SHIFT+P. I am talking about misspelled sites, etc. which you can remove by selecting the URL using up and down arrow keys in the address bar auto completion list and pressing the DELETE key.
  
  
• In a somewhat controversial decision, it was decided that if you open a group of tabs (middle-click on a bookmark folder) in Firefox, those new pages will be opened in the currently opened tabs, rather than being added. There is, however, a setting to make groups of tabs be opened in new tabs, rather than the existing ones.
  Enter about:config in the address bar. In the resulting page, search for the preference browser.tabs.loadFolderAndReplace. Double-click on it, which should change the value to false.
  
  
• Adding tags to websites: One of the Firefox 3.0 coolest feature is the improved address bar, known as the awesome bar, which allows you to search any website from your browsing history or bookmarks by typing words from that site URL or title in any order. More tricks on how to search specific URL's in awesome bar can be read at: http://www.webmonkey.com/blog/Firefox_3DOT1_Will_Add_More_Awesomeness_to_the__Awesome_Bar_. You can also bookmark any website by just clicking on the star icon in the address bar. The star would turn yellow, and the bookmark is added to unsorted bookmarks. Click on the yellow star, i.e. the bookmark button, to edit the bookmark location, i.e. to move the bookmark to any particular bookmark folder. You can also add tags to that bookmark, so that you can search that website from your address bar using those tags. I have Xmarks addon installed which would recommend some suggested tags for that website. After adding the tags, just enter those tags in the address bar to search that website.
  
  
• Visiting your favorite sites using Firefox's bookmarks is far too much of a chore -- do you really want to do all that mousing around? Instead, you can use keywords to instantly jump to any site you've bookmarked. To do it, after you bookmark a site, right-click on the bookmark, select Properties, type in a short keyword (or even just a letter or two) in the keyword field and click OK. Now, to visit the site, type in the keyword in Firefox's address bar, and you'll jump straight to the site. For unsorted bookmarks, open the Organize Bookmarks dialog using CTRL+SHIFT+B, then select that bookmark from the particular folder or unsorted bookmarks folder and add the keyword.
  
  
• Have to ever wanted to download some image or video from some webpage, e.g. image of some pretty girl from her profile on Orkut :), but couldn't as the image/video might be protected against right click and save images, and searched the page source for the image location. There is a simpler solution, just right click on the page anywhere, and select View Page Info, go to the Media tab, select the image you want to save and click the Save As... button.
  
  
• Firefox default spell checking works only for TextArea, so do you check spelling in the Input text boxes, from the right click context menu, or ignore the spellings in the Input text boxes? Well, in Firefox about:config, search for layout.spellcheckDefault and set its value to 2 to turn on Firefox's spell-checking in input fields as well as textareas, and check your spelling mistakes and typos in the input boxes also.
  
  
• Suppose you are making some report, and require to copy text phrases from webpages. Instead of copying each line, and pasting it in text editor, you can select any line, then hold the CTRL key and select another line, and soon. Once you are done, copy all the disjoint selected text to the text editor. Firefox 3 allows multiple selections within a webpage.
  
  
• Smart Keywords: Smart Keywords are an easy way to search websites right from the Location bar. How to create a smart keyword is described on Mozilla website at http://www.mozilla.org/products/firefox/smart-keywords.html. Smart keywords are really powerful, I will give you one more example apart from the IMDB example. wxWidgets latest documentation is hosted at http://docs.wxwidgets.org/stable/, but it provides no means to search it. So a created a smart keyword named wxdoc from google.com and edited it properties manually, from the bookmark menu and modified the location property to:
  http://www.google.co.in/search?btnI=1&hl=en&q=site:http://docs.wxwidgets.org/stable&q=%s
  Now I can just write wxdoc followed by the API to search in the address bar and it would search the wxWidgets website for all the references of that API using Google.
  
  
• Make Gmail the default mail client: Open your Gmail inbox and type the below javascript into the address bar and press enter key.

  javascript:window.navigator.registerProtocolHandler("mailto","https://mail.google.com/mail/?extsrc=mailto&url=%s","Gmail")

  A line will appear on top of the screen asking if you want to add Gmail as an application for mailto links. A click on Add Application adds the handler, a click on the X button closes the request and changes nothing.
  
  
• You can move to the next tab using CTRL+TAB or the previous tab using CTRL+SHIFT+TAB. You can also jump straight to any arbitrary tab by pressing CTRL + <Tab number>, like CTRL+0.
  
  
• Faster search: How many times, you select some text, copy it using CTRL+C and then press CTRL+K to go to the search box, press CTRL+P to paste it then hit Enter key, when you can just drag and drop and text you want to search to the search box. The only drawback to this is that the results page is loaded in the same, current tab.
  
  
• Reopen a closed tab using CTRL+SHIFT+T, open new tab using CTRL+T. Scroll down using SPACEBAR and scroll up using SHIFT+SPACEBAR. CTRL++ to zoom webpage and CTRL-- to zoom out a webpage. Middle click on link will open the link in new tab, while middle click on a tab closes it.
  
  
• Popups normally don't display properly in Firefox, and with resizing disabled, it makes more annoyance. Here are some other useful options which can be applied by using about:config to change the following:
  dom.disable_window_open_feature.resizable
  Set this to true to make sure all pop-up windows are resizable.
  dom.disable_window_open_feature.minimizable
  Set this to true to make sure all pop-up windows are minimizable.
  dom.disable_window_open_feature.menubar
  Set this to true to always display the menu in pop-up windows.
  dom.disable_window_open_feature.location
  Set this to true to always display the Navigation Toolbar in pop-up windows.
  dom.disable_window_open_feature.scrollbars
  Set this to true to prevent sites from disabling scrollbars.

Original link: http://priyankbolia.blogspot.com...