Important Warnings Before You Start

FastFlags are powerful tools that can cause crashes or visual issues if used incorrectly. Follow these guidelines to stay safe:

• Add flags one at a time and test after each addition
• If something breaks, remove the most recently added flag first
• Not every flag works the same on every PC. Hardware and driver configurations vary.
• Roblox updates can occasionally break specific flags. Check for community updates if a flag stops working after a Roblox update.
• For safety information about using Bloxstrap tools in general, read Is Bloxstrap Safe? Everything You Need to Know Before Downloading.

How to Add These Flags in Bloxstrap

Open Bloxstrap, go to the Fast Flags tab, and use the flag name and value fields to add each flag. After adding your flags, save settings and fully restart Roblox for the changes to take effect. All flag names are case-sensitive, so copy them exactly as written.

Category 1: FPS Cap Removal

The single most impactful flag for most players. By default, Roblox caps your frame rate at 60 FPS regardless of how powerful your hardware is. This flag removes that cap.

Flag: DFIntTaskSchedulerTargetFps
Value: 240

Set the value to whatever maximum FPS you want to target. 240 is the most common choice. If your monitor only runs at 144Hz, setting this to 144 is more appropriate. Setting an extremely high value like 9999 is not recommended and can cause instability. Note that this flag is the core mechanism behind Bloxstrap’s built-in FPS unlocker feature. Read more about that in our dedicated article at Bloxstrap FPS Unlocker: Does It Still Work in 2026?

Category 2: Rendering Mode Optimization

Roblox can use different graphics rendering backends. The default may not be the most efficient for your specific GPU and driver combination. Switching to a better renderer can yield significant FPS gains.

Flag: FFlagDebugGraphicsPreferD3D11
Value: true

This forces Roblox to use the Direct3D 11 renderer, which often performs better than the default on most Windows systems with AMD or NVIDIA GPUs.

Flag: FFlagDebugGraphicsPreferVulkan
Value: true

This forces the Vulkan renderer instead. Vulkan can outperform Direct3D 11 on some systems, particularly with AMD GPUs and modern NVIDIA cards. Do not enable both the D3D11 and Vulkan flags simultaneously. Test each one separately and keep whichever gives you better performance.

Category 3: Shadow Reduction for FPS

Shadows are one of the most GPU-intensive visual elements in Roblox. Reducing or disabling shadow quality can provide a substantial FPS boost, especially on older or budget graphics cards.

Flag: DFIntCullFactorPercent
Value: 0

This disables some culling calculations and can improve rendering efficiency in certain game environments.

Flag: DFFlagDebugRenderForceTechnologyVoxel
Value: true

This forces Roblox to use the older Voxel lighting system instead of more demanding modern lighting systems like Shadow Map or Future lighting. It significantly reduces GPU load at the cost of visual quality. Only recommended for players on lower-end hardware.

Category 4: Texture and Material Quality

Lowering texture quality reduces GPU memory usage and can increase FPS in games with many high-resolution textures.

Flag: DFIntTextureQualityOverride
Value: 1

This sets texture quality to its lowest level, which is useful for players on hardware with limited VRAM. The visual impact is noticeable but the FPS gains can be significant on affected hardware.

Category 5: Network and Performance Stability

These flags affect how Roblox handles network updates and background processing, which can improve consistency of frame times rather than just peak FPS.

Flag: DFIntConnectionMTUSize
Value: 900

Adjusting the network packet size can reduce packet fragmentation and improve connection stability, particularly relevant for players with higher ping. This works alongside the benefits you get from using the server region checker. For low-ping server selection, see Bloxstrap Server Region Checker: Find the Best Server for Low Ping.

Category 6: UI Rendering Optimization

Roblox renders its interface elements even when you are not actively using menus. Reducing UI rendering overhead can free up small amounts of GPU time for the game itself.

Flag: FFlagBatchAssetRequestsV2
Value: true

This enables batched asset loading which can reduce loading stutter when joining games and when new assets are streamed in during gameplay.

Recommended Starter Configuration for Low-End PCs

If you are on older or budget hardware and want the maximum FPS gains with the most trade-off in visual quality, use this combination:

• DFIntTaskSchedulerTargetFps = 240
• FFlagDebugGraphicsPreferD3D11 = true
• DFFlagDebugRenderForceTechnologyVoxel = true
• DFIntTextureQualityOverride = 1

This configuration prioritizes raw performance over visual fidelity and works well on PCs with integrated graphics or older dedicated GPUs.

Recommended Starter Configuration for Mid-Range PCs

For players with a mid-range GPU like an NVIDIA GTX 1060 or AMD RX 580 equivalent, this balanced configuration improves FPS without sacrificing much visual quality:

• DFIntTaskSchedulerTargetFps = 144
• FFlagDebugGraphicsPreferD3D11 = true
• DFIntConnectionMTUSize = 900

Flags That Are No Longer Working in 2026

Roblox updates periodically deprecate flags that the community previously relied on. Here are some flags that were popular in previous years but may no longer work reliably in 2026:

• Some older shadow rendering flags have been superseded by Roblox engine updates
• Certain physics threading flags were removed in 2025 Roblox engine revisions
• Some older rendering backend overrides were consolidated into newer flag names

Always check the Bloxstrap Discord for the most current working flag names if you find that a flag from an older guide is not producing expected results after a Roblox update.

Combining FastFlags With the FPS Unlocker

The FPS unlocker built into Bloxstrap and the FastFlags editor work together. The FPS unlocker applies the frame rate cap flag automatically through a convenient toggle. If you manually set the DFIntTaskSchedulerTargetFps flag in the editor, you are essentially doing the same thing as the FPS unlocker but with more precise control over the target value. You do not need to enable both.

Read the full details on the FPS unlocker at Bloxstrap FPS Unlocker: Does It Still Work in 2026?

What to Do If Flags Break Your Game

If Roblox starts crashing or behaving strangely after adding flags, open Bloxstrap and navigate to the Fast Flags tab. Remove the most recently added flags one by one, restarting Roblox after each removal to identify the problematic flag. As a last resort, you can clear all custom flags entirely to return Roblox to its completely default configuration.

Final Thoughts

FastFlags remain one of the most effective ways to improve Roblox performance in 2026. With the right combination of flags for your hardware, it is possible to see significant improvements in FPS and overall game smoothness that the default Roblox client simply cannot match.

Pair your FastFlag configuration with Discord Rich Presence from our guide at Bloxstrap Discord Rich Presence: How to Show Friends What You’re Playing and activity tracking from Bloxstrap Activity Tracking: What It Is and How to Turn It On for a complete Bloxstrap setup.