Websites may look incorrect, load improperly or stop working because of cached data, extensions, browser settings or blocked content. This article walks through the most common fixes first, then moves to more advanced troubleshooting steps.

Clear the cookies and cache

Firefox caches websites, which means it saves some files on your machine so that it doesn't have to re-download everything when you visit sites. If a website has updated their code, Firefox may still be using some of the old code along with some of the new, which can make a web page display incorrectly. To fix this, you need to clear the cookies and cache:

1. Click the menu button to open the menu panel.
2. Click History and select Clear recent history….
3. Below the drop-down menu, select Cookies and site data. Make sure other items you want to keep are not selected.
4. Click Clear.

Now that your cookies and cache are cleared, visit the website again to see if the problem is solved.

Disable extensions and themes

Extensions that block content, modify websites or change browser behavior can cause pages to display incorrectly.

1. Click the menu button and select Add-ons and themes.
2. Select the Extensions panel.
3. Turn off extensions one at a time, especially:
   • Ad blockers
   • Privacy tools
   • Script blockers
   • Appearance customization extensions
4. Reload the website after each change.

If the website works after disabling an extension, leave it disabled or remove it.

For more detailed troubleshooting, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

Test the website in another browser

Testing the website in another browser helps determine whether the problem is specific to Firefox.

• If the website fails in multiple browsers, the issue is likely with the website itself.
• If the website only fails in Firefox, continue with the advanced troubleshooting steps below.

Turn off Enhanced Tracking Protection for the website

If a site seems broken, disabling Enhanced Tracking Protection might fix the issue by allowing trackers on just that site. Enhanced Tracking Protection will still prevent trackers on other sites. To disable it:

1. Visit the website.
2. At the left of the address bar, click the shield icon.
3. At the topthe bottom of the panel, toggle off the Enhanced Tracking Protection switch . The site will be added to your Enhanced Tracking Protection exception list, allowing trackers on it, and the page will reload automatically.

   

Follow the same process to turn Enhanced Tracking Protection back on.

If the issue persists, consider reporting it by submitting a Broken Site Report. This allows the Webcompat team to examine the problem. For more information, see How do I report a broken site in Firefox desktop?

Report the website

If turning off Enhanced Tracking Protection allows a page to display and work correctly, you can report the website to help improve Firefox. See the How do I report a broken site in Firefox desktop? article for more information.

Occasionally, you may come across a page that simply doesn't work in Firefox, even when Enhanced Tracking Protection is turned off. If the same page works in another browser, please report the problem with our desktop reporting tool, or by visiting webcompat.com.

Advanced troubleshooting

Check Firefox settings and customizations

Advanced Firefox settings or modified preferences can affect how websites display.

1. Type “about:support” in the address bar and press [Return].
2. Review the following sections:
   • Modified Preferences
   • Extensions
   • Graphics
3. Look for unusual custom settings or configuration changes.

If you suspect a modified setting is causing the issue, you can troubleshoot further using Refresh Firefox - reset add-ons and settings.

Reset Zoom settings

Some websites may not look right at different zoom levels. To reset the Zoom setting for the site, press [command] + [0]. For all sites, see the documentation about the Zoom add-on you use.

Reset the minimum font size

Some sites do not display properly with a minimum font size. To reset the minimum font size:

For more information about font settings, see Change the fonts and colors websites use.

Reset the page style

You may have inadvertently set the page style to No Style. To ensure Firefox is set to use the page's default style:

• On the menu bar at the top of the Firefox window, click on the View menu, then select Page Style and click Basic Page Style.

Now that the page is using its default style, it may be displayed correctly.

Check that JavaScript is not blocked

You should check whether you have an extension (such as NoScript) or Internet security program (such as a firewall, antivirus, or anti-spyware program) that can block JavaScript. To learn more, see JavaScript settings and preferences for interactive web pages.

Disable problematic extensions or hardware acceleration

Some extensions may interfere with the way websites are displayed, or your graphics card and drivers don't display some web content correctly when hardware acceleration is turned on. Follow the instructions in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to see if one of these is causing the problem.

Check your system date and time

In some instances the loading and verification of secure web content will be time-dependent, so you should check that date, time, and timezone are set correctly on your system. If you make adjustments to one of these, reload the site afterwards.

Related links

• Websites don't load - troubleshoot and fix error messages
• Fix problems that cause images to not show
• Fix common audio and video issues

Based on information from Websites look wrong (mozillaZine KB)