FFS Docs
24,091 FastFlags with their value type, category, and which verified lists use them. 8077 have written explanations so far.
6,206 stable17,885 potentially unstableLast updated
Roblox doesn't publish documentation for these flags, so nothing here is official. Plain descriptions are hand-written from names, categories and real-world use. Ones marked AI were written by a local model from the flag name alone — it has no source to look anything up in, so treat those as a rough hint and verify before relying on them.
Stable vs. potentially unstable
Stable flags come from the curated set that's known to be useful and safe to apply. Potentially unstable flags were pulled in from the full engine dump — they're real, but untested here and may do nothing, break rendering, or stop the client launching. Try those one at a time.
Every known FastFlag is in this list.
Stable and potentially unstable together cover the full set. The stable half comes from Masterstrap/All-Fast-Flags, which covers the flags actually worth using as a player. The rest is everything else Roblox exposes, tracked by MaximumADHD/Roblox-FFlag-Tracker.
Roblox adds and removes flags with most updates, so this is a snapshot rather than a live feed — check the trackers above if you're after something brand new.
24,091 flags · showing first 60
ClientPacketExcessMicrosecondsintegerOtherLow PingExtra microseconds the client may spend processing packets beyond its normal budget.
ClientPacketMaxDelayMsintegerOtherLow PingMaximum milliseconds a packet may sit queued before it must be processed.
ClientPacketMaxFrameMicrosecondsintegerOtherLow PingUpper bound on microseconds spent processing packets in a single frame.
ClientPacketMinMicrosecondsintegerOtherLow PingMinimum microseconds guaranteed to packet processing each frame.
CSGLevelOfDetailSwitchingDistanceintegerGraphicsPotato GraphicsDistance at which CSG (solid-modelled) parts switch to a lower level of detail.
CSGLevelOfDetailSwitchingDistanceL12integerGraphicsPotato GraphicsLOD switching distance between CSG levels 1 and 2.
CSGLevelOfDetailSwitchingDistanceL23integerGraphicsPotato GraphicsLOD switching distance between CSG levels 2 and 3.
CSGLevelOfDetailSwitchingDistanceL34integerGraphicsPotato GraphicsLOD switching distance between CSG levels 3 and 4.
DebugForceMSAASamplesintegerGraphicsPotato GraphicsNon-dynamic counterpart of the MSAA override.
DebugFRMQualityLevelOverrideintegerGraphicsPotato GraphicsNon-dynamic counterpart of the FRM quality override.
DebugGraphicsPreferD3D11booleanGraphicsPotato GraphicsPrefers the Direct3D 11 backend, which is often more stable on older Windows GPUs.
DebugLimitMinTextureResolutionWhenSkipMipsintegerGraphicsPotato GraphicsNon-dynamic counterpart of the minimum-resolution limit.
DebugPauseVoxelizerbooleanDebugPotato GraphicsNon-dynamic counterpart of the voxeliser pause.
DebugSkyGraybooleanGraphicsPotato GraphicsNon-dynamic counterpart of the grey-sky flag.
DebugTextureManagerSkipMipsbooleanGraphicsPotato GraphicsNon-dynamic counterpart of the skip-mips setting.
DFFlagDebugCheckRenderThreadingunknownOtherPotato GraphicsEnables render-threading consistency checks.
DFFlagDebugDrawBroadPhaseAABBsbooleanDebugShow Hitboxes (Debug)Draws the physics broad-phase bounding boxes on screen — the debug view commonly called 'show hitboxes'.
DFFlagDebugOverrideDPIScalebooleanDebugPotato GraphicsAllows the DPI scale to be overridden manually.
DFFlagDebugPauseVoxelizerbooleanOptimizerPotato GraphicsPauses the voxeliser entirely.
DFFlagDebugPerfModebooleanDebugPotato GraphicsEnables an internal performance mode that trades visual fidelity for frame rate.
DFFlagDebugRenderForceTechnologyVoxelbooleanDebugPotato GraphicsNo ShadowsForces the cheap Voxel lighting technology instead of ShadowMap/Future, a large performance win on weak hardware.
DFFlagDebugSkipMeshVoxelizerbooleanDebugPotato GraphicsSkips mesh voxelisation, saving CPU work during loading.
DFFlagDisableDPIScalebooleanOtherPotato GraphicsDisables DPI scaling, rendering at native resolution instead of a scaled one.
DFFlagDoNotSkipMipsBasedOnSystemMemoryPSbooleanGraphicsPCLinuxNo TextureStops the engine deciding mip-skipping from available system memory, so your manual setting sticks.
DFFlagEnableMeshPreloading2booleanAvatar/CharacterPCLinuxPotato GraphicsPreloads meshes ahead of time rather than streaming them in on demand.
DFFlagRakNetUseSlidingWindow4booleanInternetLow PingEnables RakNet's sliding-window congestion control, which generally adapts to packet loss better than the older scheme.
DFFlagTeleportClientAssetPreloadingDoingExperimentbooleanOtherLow PingOpts the client into the asset-preloading experiment used when teleporting between places.
DFFlagTeleportClientAssetPreloadingDoingExperiment2booleanOtherPCLinuxLow PingSecond-generation flag for the same preloading experiment.
DFFlagTeleportClientAssetPreloadingEnabledIXPbooleanOtherLow PingEnables teleport asset preloading via Roblox's experiment system.
DFFlagTeleportClientAssetPreloadingEnabledIXP2booleanOtherLow PingSecond-generation counterpart of the IXP preloading flag.
DFFlagTeleportPreloadingMetrics5booleanOtherPCLinuxLow PingEnables metrics collection for teleport preloading.
DFFlagTextureQualityOverrideEnabledbooleanOtherPotato GraphicsNo TextureEnables the manual texture-quality override, without which DFIntTextureQualityOverride is ignored.
DFIntCSGLevelOfDetailSwitchingDistanceintegerOptimizerPCLinuxPotato GraphicsDynamic counterpart of the CSG LOD switching distance.
DFIntCSGLevelOfDetailSwitchingDistanceL12integerOptimizerPCLinuxPotato GraphicsDynamic counterpart for the level 1-2 switch.
DFIntCSGLevelOfDetailSwitchingDistanceL23integerOptimizerPotato GraphicsDynamic counterpart for the level 2-3 switch.
DFIntCSGLevelOfDetailSwitchingDistanceL34integerOptimizerPotato GraphicsDynamic counterpart for the level 3-4 switch.
DFIntDebugFRMQualityLevelOverrideintegerDebugPotato GraphicsForces the Frame Rate Manager's quality level. 1 pins the renderer to its lowest quality tier.
DFIntDebugLimitMinTextureResolutionWhenSkipMipsunknownOtherNo TextureFloor on texture resolution when mip-skipping is active. A very large value effectively removes the floor.
DFIntDebugTextureManagerSkipMipsunknownOtherNo TextureDynamic counterpart of FIntDebugTextureManagerSkipMips.
DFIntDefaultMeshCacheSizeMBunknownOtherNo TextureSize of the mesh cache in megabytes. Larger caches reload meshes less often.
DFIntRakNetNakResendDelayMsintegerInternetLow PingMilliseconds to wait before resending a packet the server reported missing (NAK). Lower means faster recovery from packet loss.
DFIntRakNetNakResendDelayRttPercentintegerInternetLow PingThe NAK resend delay expressed as a percentage of round-trip time, so recovery scales with your actual latency.
DFIntRakNetResendBufferArrayLengthintegerInternetLow PingSize of the buffer holding packets awaiting acknowledgement before they're resent.
DFIntReplicatorAnimationTrackLimitPerAnimatorintegerAvatar/CharacterPCLinuxNo Animation ReplicationCaps how many animation tracks are replicated per Animator. -1 removes replication of animation tracks, cutting network and CPU cost at the price of other players' animations.
DFIntS2PhysicsSenderRateintegerOtherPCLinuxDesync FixFakeLag FixHow often the client sends physics/position updates to the server. Higher values replicate more frequently, which reduces desync and rubber-banding.
DFIntTeleportClientAssetPreloadingHundredthsPercentageintegerOtherLow PingRollout percentage (in hundredths of a percent) for teleport asset preloading. 100000 = 100%.
DFIntTeleportClientAssetPreloadingHundredthsPercentage2integerOtherPCLinuxLow PingSecond-generation rollout percentage for the same feature.
DFIntTextureQualityOverrideintegerOtherPotato GraphicsNo TextureForced texture quality level. 0 is the lowest quality and the cheapest to render.
DFIntWaitOnUpdateNetworkLoopEndedMSintegerOtherPCLinuxLow PingHow long the update loop waits for the network loop to finish each tick.
DoNotSkipMipsBasedOnSystemMemoryPSunknownMemory/CachePotato GraphicsNon-dynamic counterpart of the above.
FFlagDebugCheckRenderThreadingbooleanDebugPotato GraphicsNon-dynamic counterpart of the render-threading check.
FFlagDebugDisableOTAMaterialTexturebooleanDebugNo TextureDisables over-the-air material textures, falling back to plain materials.
FFlagDebugDisplayFPSbooleanDebugDisplay FPS CounterShows an on-screen FPS counter.
FFlagDebugSkyGraybooleanDebugNo TextureReplaces the sky with flat grey, removing skybox rendering cost.
FFlagNewLightAttenuationbooleanOtherPotato GraphicsNo ShadowsToggles the newer light-attenuation model.
FFlagPreloadTextureItemsOption4booleanOtherNo TextureControls which texture-preloading strategy the client uses.
FFlagRenderUseTextureManager224booleanGraphicsPCLinuxNo TextureSwitches between texture-manager implementations in the renderer.
FFlagTM2SkipMipsForUnstreamable2unknownOtherNo TextureApplies mip-skipping to textures that aren't otherwise streamed.
FIntDebugForceMSAASamplesintegerDebugPotato GraphicsForces a specific MSAA sample count. 0 or 1 disables anti-aliasing.
FIntDebugFRMOptionalMSAALevelOverrideintegerDebugPotato GraphicsOverrides the optional MSAA level the Frame Rate Manager may apply.