goldstrap / fast flags
Fast Flags
Fast Flags are client settings that Roblox reads at startup. Goldstrap writes them into the client before launching it, so you do not have to edit JSON by hand.
What they are
Roblox builds its client with a long list of named settings and allowlists a subset of them for local use. Goldstrap writes those into ClientSettings\ClientAppSettings.json inside its mods folder, which is then copied into the client at every launch.
They are client-side. They change how your game renders or behaves, never what the server does, and not every flag you have seen in a forum post is still allowed.
The manager
Settings → Fast Flags → Use Fast Flag Manager
On by default. While it is on, Goldstrap owns ClientAppSettings.json and rewrites it from the flags shown in the editor. Turn it off if you would rather maintain that file yourself — Goldstrap will then leave it alone and use whatever you put there.
The editor
Settings → Fast Flags → Open the editor
| Action | Notes |
|---|---|
| Add a flag | Name and value, or paste a JSON object and let the editor split it. |
| Import JSON | Braces are completed if you forget them, comments and trailing commas are tolerated. More than 16 entries asks first; so does overwriting a flag that already exists. |
| Edit | Names and values are editable in place. Renaming to a name that exists is refused. |
| Delete | Removes the flag from your set. Multi-select works. |
| Show preset flags | Presets are hidden by default so the list stays readable. |
| Export JSON | Copies your set to the clipboard, with or without the preset flags. |
Flags are stored as text. Delete a flag rather than setting it to false if you want the client to use its own default again.
Presets
Presets are groups of flags with a sensible range, so you do not need to know the names.
| Preset | Writes |
|---|---|
| Anti-aliasing | FIntDebugForceMSAASamples — 1, 2 or 4. Off returns the client to its own setting. |
| Fix display scaling | DFFlagDisableDPIScale, for small UI on high-DPI screens. |
| Quality override | DFIntDebugFRMQualityLevelOverride, 1 to 21. Pins the render quality and greys out the in-game slider, which is why the Global Settings page clears it when you set quality there. |
| Mesh detail | Four level-of-detail distances (DFIntCSGLevelOfDetailSwitchingDistance and its L12, L23, L34 variants). |
| Rendering mode | FFlagDebugGraphicsPreferVulkan, …D3D11 or …OpenGL. Only one is set at a time. |
| Reset configuration | Clears every flag in one go. Reversible until you save. |
Goldstrap keeps FFlagHandleAltEnterFullscreenManually set to False so its own fullscreen handling keeps working. Leave it alone unless you know why it is there.
Uncapped frame rate
Settings → Fast Flags → Uncapped frame rate
Roblox caps its client at 60 frames per second by default. This toggle sets DFIntTaskSchedulerTargetFps to 240 and the matching FramerateCap in the client's settings file. Turning it off removes the flag and returns the cap to the client default.
What it does not do: it does not raise the frame rate past what your machine can draw, and it does not change textures, shadows or model detail. On a 60 Hz display you will see no difference at all; on 120 Hz and above you will, and the GPU will be busier, which means more heat and power.
On a laptop or a low-end desktop, an uncapped frame rate can make the game run cooler but slower if the GPU starts throttling. Turn the toggle off and compare before you keep it.
Where the file goes
The file is written to %LOCALAPPDATA%\Goldstrap\Modifications\ClientSettings\ClientAppSettings.json and copied into the client on launch. If you edit it by hand while the manager is on, your next save from the settings window replaces it.