Modifying Firefox's File Download Settings via About:config

Change how Firefox handles PDFs and other downloads

Downloading files through the Firefox browser all seems fairly straightforward. You click on a link, possibly choose where to save the file, and wait for the file transfer to be completed. You have more control over this process than you probably realize, however, as the browser offers the ability to tweak several download-related settings in Firefox: change download location, display plugins, and more.

This article is only intended for users running the Mozilla Firefox browser.

Accessing the About:config Interface

You can make these modifications behind the scenes through Firefox's about:config preferences, and we show you how it's done below.

The about:config interface is very powerful, and some modifications made within it could have serious effects on both your browser and system's behavior. Proceed with caution.

Firefox about:config warning
  1. First, open Firefox and type the following text in the browser's address bar: about:config. Next, hit the Enter key. You should now see a warning message, stating that this may void your warranty. If so, press I'll be careful, I promise!

    Firefox configuration
  2. A list of Firefox preferences should now appear in the current tab. In the Search field provided, enter the following text: All download-related choices should be visible.

    To modify the value of a preference that has a boolean type, simply double-click on it to instantly toggle true or false. To modify the value of a preference that has an integer or string type, double-click on it and enter the desired value in the pop-up dialog box.

    The following preferences dictate Firefox's download-related behavior and can be modified accordingly.


    Type: boolean

    Default Value: true

    Summary: When it is set to true, the Downloads button (represented by a down arrow icon) in Firefox's main toolbar becomes animated while one or more file downloads are taking place. This animation includes a miniature progress bar.

    Firefox configurations download notifications

    Type: integer

    Default Value: 1

    Summary: When this is set to 0, Firefox will save all files downloaded via the browser on the user's desktop. When set to 1, Firefox stores these downloads in the Downloads folder. When set to 2, Firefox utilizes the location specified for the most recent download again.

    Firefox download folder list

    Type: boolean

    Default Value: true

    Summary: If a particular plugin does not have one or more file extensions associated with it, Firefox will not list it as an option when prompting what action to take with a downloaded file. If you would like all plugins displayed in the Download Actions dialog, even those without any inherent file extension associations, then you should change the value of this preference to false.

    Firefox configuration hide plugins without extensions

    Type: boolean

    Default Value: true

    Summary: Only applicable to users running the Windows operating system, Firefox adds all recently downloaded files to the OS's Recent Documents folder. To prevent downloaded files downloaded from being added to this folder, change the value of this preference to false.

    Firefox configuration add to recent docs

    Type: integer

    Default Value: 10000

    Summary: Firefox can resume file downloads that have paused. The value of this preference, measured in milliseconds, dictates how long the browser should wait after your computer returns from hibernation or sleep mode to attempt to resume any paused downloads.

    Firefox configuration download resume on wake

    Type: boolean

    Default Value: false

    Summary: When a download or multiple downloads are taking place, Firefox will not show the pop-out panel detailing the progress of each file transfer unless you proactively click on the Downloads button in the browser's toolbar. However, if you set the value of this preference to true, that panel will automatically appear, overlaying a portion of your main browser window, as soon as a download begins.

    Firefox configuration download panel

    Type: integer

    Default Value: 4000

    Summary: The filename of most downloads matches the URL of the download itself. An example of this would be In this case, the filename is simply test-download.exe and would be saved as such on the hard drive if we chose to download this file. However, some websites use a Content-Disposition header field to specify a filename different than the one found in the URL. By default, Firefox will request this header information for 4000 milliseconds (4 seconds). If it does not retrieve a Content-Disposition value within this timeframe, a timeout will occur, and the browser will resort to the filename specified in the URL. If you would like to lengthen or shorten the amount of time it takes for this to occur, simply change the value of this preference.

    Firefox configuration save link timeout

    Type: boolean

    Default Value: true

    Summary: Similar to the preference described above, this entry also influences the behavior of Firefox's Download Actions dialog. By default, associated file types and available actions appear next to each installed plugin. If you would like to stifle this display, change the value of this preference to false.

    Firefox configuration show plugins

    Type: boolean

    Default Value: true

    Summary: Whenever a download starts through Firefox, that file will be saved in the location specified in the preference, detailed above. If you wish to be prompted for a location each time a download begins, change the value of this preference to false.

    Firefox download configuration directory
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