How to stop Firefox from making automatic connections
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- Revision id: 7568
- Created:
- Creator: Michael Verdi
- Comment: added summary and keywords
- Reviewed: Yes
- Reviewed:
- Reviewed by: Verdi
- Is approved? Yes
- Is current revision? No
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Some people are particularly concerned about the connections Firefox makes to the internet, especially when such connections are made with no apparent cause. This article will explain the various reasons why Firefox may legitimately make a connection to the internet, and how you can stop it from doing so if you so desire.
Table of Contents
Loopback connection
A loopback connection (to IP address 127.0.0.1) can be made by Firefox on non-Unix machines. In this case the browser is communicating with itself as expected, and it is not recommended that this communication be blocked. See bug 100154 for more information.
Live Bookmarks updating
Live Bookmarks - Subscribe to a web page for news and updates automatically reload themselves on a regular basis, and in doing so will make a connection to the internet. Deleting all your Live Bookmarks will stop these connections from being made.
Auto-update checking
Firefox occasionally checks to see if any updates are available for itself, for your add-ons (extensions, themes, etc), and for your search engines. To disable these checks:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the icon.
- Select the tab.
- Uncheck Firefox, Installed Add-ons, and Search Engines.
Home page loading
Your home page may be loading. To change your home page to something that doesn't generate connections to the internet:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the panel ( panel in Firefox 3.5).
- Set When Firefox starts to Show a blank page.
Anti-phishing list updating
The phishing protection list may be updating itself. To turn this off:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the panel.
- Uncheck Block reported web forgeries.
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the icon.
- Uncheck Tell me if the site I'm visiting is a suspected forgery.
Anti-malware list updating
The malware protection list may be updating itself. To turn this off:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the panel.
- Uncheck Block reported attack sites.
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Select the icon.
- Uncheck Tell me if the site I'm visiting is a suspected attack site.
Add-on list prefetching
Each time the Add-ons window is opened, Firefox prefetches a list of add-ons to improve responsiveness of the
pane. This connection is not made if the add-ons manager is not opened.
Link prefetching
Firefox will prefetch certain links if any of the websites you are viewing uses the special prefetch-link tag. For more information, please see the Link Prefetching FAQ. To disable prefetching:
- Type about:config in the address bar and press EnterReturn.
A warning page may appear. Click to go to the about:config page. - In the about:config page, search for the preference network.prefetch-next.
- Observe the Value column of the network.prefetch-next row.
- If it is set to false then do nothing.
- If it is set to true, double-click on it to set it to false.
Extension blocklist updating
Firefox may be updating its extension blocklist. For more information, see Add-ons that cause stability or security issues are put on a blocklist. To disable this:
- Type about:config in the address bar and press EnterReturn.
A warning page may appear. Click to go to the about:config page. - In the about:config page, search for the preference extensions.blocklist.enabled.
- Observe the Value column of the extensions.blocklist.enabled row.
- If it is set to false then do nothing.
- If it is set to true, double-click on it to set it to false.
Live Title updating
If you have any Live Title bookmarks, they may be updating themselves. To disable Live Title bookmarks:
- Type about:config in the address bar and press EnterReturn.
A warning page may appear. Click to go to the about:config page. - In the about:config page, search for the preference browser.microsummary.enabled.
- Observe the Value column of the browser.microsummary.enabled row.
- If it is set to false then do nothing.
- If it is set to true, double-click on it to set it to false.
Extensions
An extension you have installed may be making a connection to a website that it relies on. For example, a connection to a website to synchronize your bookmarks, a connection to a website to update a list of sites to block, etc. Or it is possible an extension could be changing the expected behavior of Firefox in other ways. For example, FasterFox extension has an option to prefetch all links.
To easily disable all of your extensions please read the Diagnose Firefox issues using Troubleshoot Mode article, paying particular attention to the Disable all add-ons option under the section.
Downloads restarted
When you start Firefox, any interrupted downloads from your previous browsing session may be automatically resumed.
- From the menu bar at the top of the Firefox window, select the menu and then select the menu item.
- Ensure nothing is currently being downloaded
Infected with malware
If your machine is infected with a virus, trojan, or spyware, then Firefox's internet connection may be being piggybacked in order for the malware to communicate with its author or to deliver adverts onto your machine, etc. If you suspect this is the case, consider seeking specialized advice from one of these malware support sites:
Please be aware that Mozilla is not responsible for the content of third-party websites.
Based on information from Connections established on startup - Firefox (mozillaZine KB)