My browser of preference is Firefox for many different reasons: Security, add-ons and customizability. Today’s post will focus on one of the lesser known aspects of Firefox’s customizability – the “about:config” settings.
To get to these settings, open a new tab in Firefox, type “about:config” into the URL bar (also called the “Awesomebar” in Firefox lingo) and load the page (hit Enter).
At the “This might void your warranty!” page – click the “I’ll be careful, I promise!” button. This will take you to a humongous list of undocumented settings. In addition to the ones listed – you can even create & add your own!
Disclaimer: You can easily break Firefox by changing settings that you don’t understand. Please reference the comprehensive list of about:config options here: http://kb.mozillazine.org/About:config_entries
This list is the basic list of settings that I immediately change/create whenever I setup a new instance of Firefox. All of them help me browse the web faster and/or safer.
Faster tips:
1: Disable the Delay When Installing New Extensions
When you install a new extension in Firefox, there is a countdown of 5 seconds delay before you can install the add-on. To regain those 5 seconds of your life, in the “Search” field on the about:config screen, search for security.dialog_enable_delay and set the value to “0”.
2: Don’t Close Firefox after Last Tab is Closed
One of my pet peeves in Firefox is that by default, it will close the entire program if you close the last tab. To stop this behavior, set the browser.tabs.closeWindowWithLastTab setting to “False”.
3: Open Search Results in a New Tab
If you use the default search box in Firefox (I actually disable mine & just search from the Awesomebar), you can force Firefox to open search results in a new tab so that it does not override the page you’re currently viewing.
To do so, search for browser.search.openintab and double-click the setting to change it to “True”.
4: Force Spell Checking in all Text Boxes
By default, Firefox only spell checks words that are typed in multi-line text boxes. To force Firefox to spell check words in all text boxes, search for layout.spellcheckDefault and set the value to “2”.
5: Preview Tabs
In Windows you can cycle through open programs using the “Alt”+”Tab” keys. In Firefox you can do the same thing with “Ctrl”+”Tab”. To preview a tab before viewing, set the browser.ctrlTab.previews setting to “True”. (Note: This only seems to work if you have 3+ tabs open, 2 tabs just switches without previews.)
Safer tips:
1: Show “http” in the Awesomebar
By default, Firefox cleans up the URL displayed in the Awesomebar. This makes it difficult to ensure that you’re on a https (secured) vs. http (unsecured) website. To show the http(s) section of a URL, set the browser.urlbar.trimURLs setting to False.
2: Turn off Geo-Location
Firefox is pretty good about alerting you when a website wants to know your location – if you’re like me & don’t want ANY websites tracking your location, you can force Firefox to never report (or annoy you by asking to report) your location to a website by setting the geo.enabled setting to “False”.
3: Set encryption preferences
When you connect to an “https” secure website, the server has a list of different types of encryption protocols and ciphers that it can handle. The server also “prefers” certain ones over others.
These preferences are set by the server admin and may be set to “prefer” a lower form of encryption for many reasons. They may want less powerful encryption to lower processing overhead on the server, or they may not understand what they are doing when they set it up, etc.
You can force Firefox to only use certain protocols and ciphers, however certain websites may fail to load in which case you will need to determine what type of encryption they allow and then turn that type back on. (See my articles on HTTPS Protocols and Ciphers and HTTPS Protocols and Ciphers Continued for more information).
Search for each of the following settings & modify every setting that’s returned as follows:
- tls Set all Boolean lines to “True”
- ssl2 Set all Boolean lines to “False” (Note: Newer versions of Firefox will not even list any ssl2 options.)
- ssl3 Set all Boolean lines to “False” EXCEPT lines that contain “aes_128” or “aes_256”. The AES encryption algorithm is much stronger than the RSA or RC4 ciphers.
- EXCEPTION: “security.ssl3.rsa_des_ede3_sha” Initially set this setting to “False” – however, this is the weakest cipher and may be needed for some older SSL sites so if you find certain sites are not working, this is probably the culprit – try setting this back to “True”.
Excellent Tips 