[Fix] Mozilla Firefox Automatically Suspends Tabs and Reloads When You Visit

PROBLEM SYMPTOM:

You use Mozilla Firefox web browser to visit websites. The problem occurs when you have opened several tabs in Firefox and it automatically suspends some tabs. In other words, Firefox unloads or discards some running tabs and when you visit those tabs again, Firefox reloads the tabs from start/scratch. It wastes time and Internet bandwidth in refreshing the tabs again. Although you already visited those tabs just few minutes back but as soon as you move to other tab, Firefox automatically suspends tabs.

Mozilla_Firefox_Automatically_Reloads_Tabs_Upon_Visit.png

It becomes irritating when you have to wait while Firefox reloads tabs for you.

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It might become problematic sometimes when a webpage is running a javascript to process some important task and Firefox suspends the tab without your knowledge. When you visit the tab again, you realize that Firefox suspended the tab and you lost the processed data. Now you need to run javascript again and keep the tab opened and active so that the javascript keeps running and processing data. You can’t move to other tabs.

PROBLEM REASON:

You’ll be surprised to know that it’s a new feature introduced in newer versions of Firefox (v67 and later). New versions of Firefox browser come with this new feature called “Suspend unused or idle tabs“. This feature regularly checks the amount of free memory (RAM) available in your computer and if it detects that your computer’s memory is running low, it starts suspending unused/idle tabs to free up memory resources. What are unused or idle tabs? These are the tabs that you haven’t used or visited in a while. After automatic suspension of tabs, if you decide to review the tab, Firefox reloads the tab for you.

Here the problem is the suspension process is automatic and Firefox doesn’t ask users permission before suspending tabs. At least Firefox should show a confirmation alert or notification prompt before suspending tabs, so that user can know that a particular tab is going to suspend. If the user doesn’t want Firefox to suspend/discard tab, he can visit the tab immediately to prevent the suspension.

Currently Firefox suspends tabs if the computer’s memory (RAM) is lower than 400MB.

If you are wondering how Firefox decides which tabs should it suspend first? Here is the order in which Firefox starts suspending unused tabs:

First Firefox suspends tabs that are not pinned and not playing audio/video. After that it suspends pinned tabs that are not playing audio/video. At last it suspends tabs that are playing audio/video.

This feature was implemented in Firefox as several users used to complain that Firefox consumes too much memory. With the help of this feature, Firefox can free up memory by unloading idle or unused tabs from memory.

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But visiting a tab again and finding that it was automatically suspended by Firefox and then waiting for the tab to reload may start annoy users.

PROBLEM SOLUTION:

Fortunately Firefox comes with a built-in preference/flag to disable or turn off this new tabs suspension feature. If you are facing problems with this new feature and you want to restrict/prevent/block Firefox from automatically suspending your tabs, you can permanently deactivate this feature with the help of following steps:

1. Open Mozilla Firefox and type about:config in the addressbar and press Enter. It’ll show you a warning message, click on “I accept the risk!” button. It’ll open Firefox’s hidden secret advanced configuration page i.e. about:config page.

2. Now type lowmemory in Search filter box and it’ll show following preference in the window:

browser.tabs.unloadOnLowMemory

The preference value is set to true by default, which means the new tabs suspension feature is enabled in Firefox browser.

3. To completely deactivate and disable tabs suspension feature in Firefox, double-click on browser.tabs.unloadOnLowMemory preference and set it to false. Alternatively, you can right-click on the preference and select Toggle option.

Mozilla_Firefox_Suspends_Unloads_Discards_Tabs_On_Low_Memory.png

That’s it. Restart Firefox and it’ll no longer suspend/discard your opened tabs.

PS: In future, if you decide to re-enable the tabs suspension feature in Firefox, set the value of above mentioned preference to true again.

In my opinion, Firefox should provide an option to customize low memory amount which is set to 400MB at the moment. Also there should be a way to add desired tabs to exception list so that Firefox doesn’t suspend those tabs automatically.

Also Check:

[Fix] All Bookmarks, Add-ons and Settings Lost, Mozilla Firefox Opens Like a Fresh Installation With New Blank Profile

PS: Google Chrome and Microsoft Edge web browsers users can enable similar feature using following tutorials:

[Tip] Enable Tab Freeze or Tab Suspend Feature in Google Chrome

[Tip] Enable Secret “Sleeping Tabs” Feature in Microsoft Edge Web Browser

Published in: Mozilla Firefox, Troubleshooting Guides

About the author: Vishal Gupta (also known as VG) has been awarded with Microsoft MVP (Most Valuable Professional) award. He holds Masters degree in Computer Applications (MCA). He has written several tech articles for popular newspapers and magazines and has also appeared in tech shows on various TV channels.

Comments

NOTE: Older comments have been removed to reduce database overhead.

  1. Muchas gracias por este truco. Estuve buscando antes y no encontré nada.

    Usted conoce algún truco para forzar la desactivación de espacio reservado en Windows 10 actualización de mayo 2019? He probado lo de la clave del registro ShippedWithReserves a 0 o 1 y no me funciona de ninguna manera Le agradezco de antemano.

  2. Well, very nice explained… it was getting so frustrating but you saved my day, was about to throw out my lap out of the window. I owe y a bear.

  3. I just downloaded and installed Firefox 68.1.1. for Android. The configuration option you mention (browser.tabs.unloadOnLowMemory) seems not to exist in this version.

  4. Firefox 56.0.2 does the same thing,
    but there is no “browser.tabs.unloadOnLowMemory” to disable.

  5. That option is already set to “false” and it still suspends background tabs. I am using version 69.03. It was doing this even before my last upgrade. With all the BS about Flash I am about ready to tell Firefox to ki$$ my arse.

  6. “The preference value is set to true by default, which means the new tabs suspension feature is enabled in Firefox browser.”
    Hmm, my Firefox 71.0 browser.tabs.unloadOnLowMemory is set to false by default.

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