Firefox can't load websites but other browsers can

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  • Revision id: 186318
  • Created:
  • Creator: Vipin Kumar
  • Comment: I faced a problem of "no loading" of any link and it was because of adblocker. Found another question on stackoverflow with simillar problem but with different extension. So decided to add "Check if an Extension is causing the problem" to the article.
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: AliceWyman
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: No
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This article describes problems where Firefox cannot load websites, but other web browsers (such as Internet ExplorerSafariEpiphany on Gnome or Konqueror on KDE) can. When this happens, Firefox may show a Server not found or Unable to connect error message.

Internet Security software blocking Firefox

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.

Note: 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. For instructions on how to configure some programs, see the Configure firewalls so that Firefox can access the Internet article.

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. To check your connection settings in Firefox:

  1. In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.Click the menu button Fx89menuButton and select Settings.
  2. Select the Advanced panel.
  3. Select the Network tab.
  4. In the Connection section, click Settings….
  5. Change your proxy settings:
  6. Close the Connection Settings window.
  7. Close the Settings page. Any changes you've made will automatically be saved.
  1. In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.Click the menu button Fx89menuButton and select Settings.
  2. In the General panel, go down to the Network Proxy section.
  3. In the Network Proxy section, click Settings….
  4. Change your proxy settings:
  5. Close the Connection Settings dialog.
  6. Close the Settings page. Any changes you've made will automatically be saved.

If you find that changes you make to your Firefox connection settings are not remembered when you restart Firefox, see 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 EnterReturn.
    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, double-click 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 EnterReturn.
    A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
  2. Right-clickHold down the control key while you click in the list of preferences, select New, and then select Boolean.
  3. In the Enter the preference name field, enter network.dns.disablePrefetch and click OK.
  4. Select true when prompted to set the value and click OK.

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 the menu button Fx89menuButton 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 OKClear Now.

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:

Check if an Extension is causing the problem

Sometimes some extension could be causing the issue, especially the ones that have network access and\or rely on manipulating the web-content. Try disabling them one by one and try reloading the webpage.



Based on information from Error loading websites (mozillaZine KB)