Firefox unable to load websites, other browsers can

If you are one of the user who is able to load websites on other browsers but not on Firefox, then this write up is for you.
You could be facing this issue possibly because Firefox may show a server not found or unable to connect error message.
Today let us learn the possible reasons, solution and prevention for browserrelated issues.

Firefox can’t load websites but other browsers can
Now if you were able to load websites until you updated Firefox or until your Internet security software was updated, reconfigured or a new one was added, your Internet security software (including firewalls, antivirus programs, anti- spyware programs, and more) is likely preventing Firefox from connecting to the Internet. In addition to that, note that Some Internet security programs can block Internet access even when they are in a “disabled” state.

In general, you should make sure your Internet security software is up-to-date and remove Firefox from your program’s list of trusted or recognized programs, then add it back.

Firefox connection settings
If you connect to the Internet through a proxy server that is having connection problems, you will not be able to load websites.

1. Click the menu button  and select Settings.
2. In the General panel, go down to the Network Settings section.
3. In the Network Settings section, click Settings….
4. Change your proxy settings:
   1. If you don’t connect to the Internet through a proxy (or don’t know whether you connect through a proxy), select No Proxy.
   2. If you connect to the Internet through a proxy, compare Firefox’s settings to another browser’s  (such as Internet Explorer or Chrome).
5. Close the Connection Settings dialog.
6. Close the about:preferences page. Any changes you’ve made will automatically be saved.

If you find that the changes you made to your Firefox connection settings are not saved when you restart Firefox, check out how to fix preferences that won’t save.

IPv6

Firefox supports IPv6 by default, which may cause connection problems on certain systems. To disable IPv6 in Firefox:

1. Type about:config in the address bar and press Enter.
   A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
2. In the Search field, enter network.dns.disableIPv6.
3. In the list of preferences, click the Toggle button next to network.dns.disableIPv6 to set its value to true.

DNS Prefetching

Firefox attempts to speed up loading new websites by using DNS Prefetching, which can cause page load errors with some system configurations. To disable DNS Prefetching:

1. Type about:config in the address bar and press Enter.
   A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
2. Enter the preference name network.dns.disablePrefetch in the about:config search bar.
   If the preference doesn’t already exist, select Boolean and click the Add button.
3. Press the Toggle button to set the preference value to true, if it’s not already set.

Firefox cannot load certain websites
If you find that Firefox can load some websites but not others, first clear your Firefox cookies and cache:

1. Click on the menu button to open the menu panel.
2. Click History and select Clear Recent History….
3. In the Time Range to clear: drop-down, select Everything.
4. Below the drop-down menu, select both Cookies and Cache. Make sure other items you want to keep are not selected.
5. Click OK.

Check for malware

If clearing your cookies and cache did not enable you to load the websites that did not work in Firefox, you should check your computer for malware. Certain types of malware are known to target Firefox and can prevent it from loading various websites:

• If you have an antivirus or Internet security program, update its detections database and do a full scan of your system.
• If you still have problems, follow the instructions in Troubleshoot Firefox issues caused by malware.

Check if an extension is causing the problem

A Firefox extension could be causing the issue, especially the ones that have network access and/or those that rely on manipulating webpage content. Try disabling your extensions in the Add-ons Manager one by one and then reload the page. See Disable or remove Add-ons and Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems for more information.