Editing Firefox handlers.json To Open Browser or External Links in a Same Tab, New Tab or New Window

gistfile1.txt

# Editing Firefox `handlers.json` To Open Browser or External Links in a Same Tab, New Tab or New Window

Sourced from: https://support.mozilla.org/bm/questions/1258193
Thanks to: [jscher2000](https://support.mozilla.org/bm/user/jscher2000/)

See `about:support` for help finding the profile folder.
See `about:config` for updating settings in a UI.

I'm going to show all three of these related preferences:

(1) In a new tab, type or paste `about:config` in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste neww and pause while the list is filtered

(3) Review/Adjust the preferences as follows:

(A) browser.link.open_newwindow - for links in Firefox tabs

This is the one that has a checkbox on the Preferences page:

    3 = divert new window to a new tab (default)
    2 = allow link to open a new window
    1 = force new window into same tab 

(B) browser.link.open_newwindow.restriction - for links in Firefox tabs

By default, if a page sets width, height, or toolbars for a popup, Firefox will let it be a separate window. To force those into a tab as well, you can change this preference to 0:

    0 = apply the setting under (A) to ALL new windows (even script windows with features)
    2 = apply the setting under (A) to normal windows, but NOT to script windows with features (default)
    1 = override the setting under (A) and always use new windows 

(C) browser.link.open_newwindow.override.external - for links in other programs

    -1 = apply the setting under (A) to external links (default)
    3 = open external links in a new tab in the last active window
    2 = open external links in a new window <= Try this one
    1 = open external links in the last active tab replacing the current page 

To return to normal if things go haywire, right-click each "modified" preference and choose Reset.