Setting Firefox to Open Long Previously Opened Windows

Introduction

In this article, we will discuss how to configure Mozilla Firefox to open long previously opened windows. This is a useful feature, especially if you have a habit of leaving numerous windows open and want to continue your work from where you left off. We will be using Firefox version 134.0.1 for this demonstration.

Related Concepts

Saving Session Data

Firefox can save session data, including tabs, windows, and form entries, automatically or manually. This feature can help users quickly recover their previous browsing activities, making it a convenient option for productivity and continuity.

Session Restore

Session Restore, a built-in mechanism in Firefox, allows the browser to reopen the last browsing session automatically upon launch or after a crash. Users can customize this feature to their preferences, including restoring long previously opened windows.

Configuring Firefox to Open Long Previously Opened Windows

To set Firefox to open long previously opened windows, follow these step-by-step instructions:

1. Launch Firefox: Open the Firefox application on your computer.
2. Access Settings: Click on the menu button (three horizontal lines) at the top-right corner and choose Options from the drop-down list.
   <menu>
  <menupopup>
    <menuitem label="Options" />
  </menupopup>
</menu>
3. Privacy and Security: In the left-side panel, click on Privacy & Security.
4. History: Find the History section and click on the Settings... button to proceed.
   <hbox>
  <button label="Settings..." />
</hbox>
5. Firefox Will: In the History Settings dialog, change the drop-down menu option of Firefox will: to Use custom settings for history.
6. Clear History: Ensure that the options for Browsing & Download History, Form & Search History, and Cookies are unchecked to your preference.
   <checkbox label="Browsing & Download History" checked="false" />
<checkbox label="Form & Search History" checked="false" />
<checkbox label="Cookies" checked="false" />
7. Restore Previous Session: Check the box for Always restore my previous session and close the History Settings dialog.
   <checkbox label="Always restore my previous session" checked="true" />

Additional Tweaks for Power Users

For even more control over how Firefox handles opening previously opened windows, you can use about:config and toggle several settings mentioned below.

Accessing about:config

Enter about:config in the Firefox address bar, accept the warning, and proceed.

Pertinent Settings

1. browser.sessionstore.max_tabs_undo: By default, this value is set to 10. To increase it, double-click the option and change its value to your preference, for example, 50 to allow undoing closing up to 50 tabs.
   <preference name="browser.sessionstore.max\_tabs\_undo" type="integer" value="50" />
2. browser.sessionstore.max_windows_undo: Similarly, this value is typically 3. You can increase it by double-clicking the option and setting its value to a desired value, like 10 for up to 10 undoable windows.
   <preference name="browser.sessionstore.max\_windows\_undo" type="integer" value="10" />

Summary and References

• Mozilla Firefox Support - Restore Previous ```less Session
• MDN Web Docs - Using about:config
• Mozilla Firefox Support - What is about:config?