Opens via File › Preferences.
Controls QtFRED editor settings. Changes take effect immediately; there is no Apply button. The exception is a handful of graphics settings that the renderer can only read while it is starting up - those are marked below, and QtFRED applies them the next time it is launched.
Miscellaneous editor options. Hover over each setting for a tooltip description.
QtFRED periodically saves a background copy of the mission you are editing so that work can be recovered after a crash. Autosaves are written to a separate autosave folder and never overwrite the mission file you are working on.
Replaces the Objects, Environment, Mission, Narrative and Tools menus with the two menus FRED2 used: Editors, which lists every editor dialog, and Misc, which holds the object and subsystem commands and the remaining tools. The menu items and their shortcuts are the same in both layouts, and the change takes effect immediately.
Controls how the 3D viewport is rendered. These settings affect the editor only - they are stored separately from the game's own graphics options and never change them.
Enable post-processing in the viewport routes the viewport through the same HDR rendering pipeline the game uses, adding bloom, tonemapping, and lightshafts. It is off by default, so missions look the way they always have until you opt in. The same switch is available as View › Enable Post Processing.
Every other setting in this section only changes what you see while post-processing is on, because they are all consumed by that pipeline.
Brightness of the viewport, from 0.10 to 5.00. QtFRED defaults this to 3.00, higher than the game, because the viewport is not tonemapped unless post-processing is enabled. Applies immediately.
Configures the reference grid shown in the main viewport. You can set which world-space plane the grid lies on (XZ, XY, or YZ) and adjust the grid's center point to move it to a different position in the world. Use Reset grid to restore the plane and center to their defaults.
Allows remapping the default input controls, such as camera movement and viewport navigation. Hover over each entry for a description of what it does. The default keyboard bindings are listed on the Viewport page.