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Widescreen & Custom Resolutions

CirrusRO runs at whatever resolution you want, including ultrawide (21:9) and high-DPI panels that the in-game menu doesn't list. If your monitor is a normal 16:9 size, you can just pick it from the in-game Graphics menu. For anything else, set it once in a small text file and the client will use it every launch.

Short version

Play in windowed mode and set your monitor's size in savedata\OptionInfo.lua. Windowed mode accepts any width and height, so ultrawide and custom sizes just work.

When do I need this?

You want... Do this
A standard 16:9 size (1920x1080, 2560x1440, ...) Use the in-game Graphics menu. No file editing needed.
Ultrawide 21:9 (3440x1440, 2560x1080, ...) Use the steps below.
4K / high-DPI, or any size not in the menu Use the steps below.
A windowed size that matches your monitor exactly Use the steps below.

Steps

1. Launch the game once and log out. This makes the client create your settings file if it isn't there yet. (If you have played before, it already exists.)

2. Open the settings file in Notepad:

<your CirrusRO folder>\savedata\OptionInfo.lua

For example, if you extracted the client to G:\CirrusRO, the file is G:\CirrusRO\savedata\OptionInfo.lua.

3. Find these three lines (they may be in any order) and set them to your monitor's size. To run windowed at 3440x1440:

OptionInfoList["ISFULLSCREENMODE"] = 0
OptionInfoList["WIDTH"] = 3440
OptionInfoList["HEIGHT"] = 1440
  • ISFULLSCREENMODE = 0 means windowed (required for custom sizes).
  • WIDTH / HEIGHT are your resolution in pixels.

4. Save the file and launch the game. It opens at your size.

Want it to fill the screen?

Set WIDTH / HEIGHT to your monitor's exact resolution. A windowed client at your full monitor size looks and feels like fullscreen, with none of the ultrawide restrictions.

Tested resolutions

Any size works, but here are common ones. Ultrawide and 4K should use windowed (ISFULLSCREENMODE = 0).

Aspect Resolution Notes
16:9 1600 x 900
16:9 1920 x 1080 Full HD
16:9 2560 x 1440 QHD
16:9 3840 x 2160 4K -- interface elements look small, but everything works
21:9 2560 x 1080 ultrawide
21:9 3440 x 1440 ultrawide (UWQHD) -- player-tested
21:9 3840 x 1600 ultrawide
16:10 1680 x 1050
16:10 1920 x 1200
4:3 1024 x 768 classic minimum

Minimum size

Keep both numbers at 1024 x 768 or larger. Below that the interface starts to clip at the edges.

Good to know

Don't change resolution from the in-game menu afterwards

Once you've set a custom size in the file, leave the resolution alone in the in-game Graphics menu. Applying a resolution there overwrites your custom size with a standard one. If you want to change it later, edit OptionInfo.lua again.

  • Ultrawide (21:9): the game world fills the whole screen and you see more of the map. The interface windows sit toward the edges; a few fixed backgrounds (like the login screen) may show bars on the sides. This is normal and does not affect gameplay.
  • 4K: everything renders sharply, but the interface and text are not scaled up, so they look small. Many players prefer 2560x1440 windowed on a 4K panel for a larger interface.
  • This is a display setting only. It gives no gameplay advantage and is completely safe to use.

Reset to default

If anything looks wrong, delete the file and the client rebuilds it fresh on next launch:

<your CirrusRO folder>\savedata\OptionInfo.lua

Delete it, start the game, and pick a resolution from the in-game Graphics menu.

Need help?

Ask in the #support channel on our Discord and include your monitor's resolution.