Bloxstrap Optimization Flags

Important Update (October 2025): As of Roblox’s recent update, only a limited allowlist of Fast Flags can be modified locally. Most performance and networking flags no longer have any effect. Additionally, Bloxstrap v2.10.0 and newer have disabled the Fast Flag Editor due to these restrictions.

If you’re using an older version of Bloxstrap, the steps below still apply—but note that Roblox may ignore or override most flags.

Applying Flags (for older Bloxstrap versions)

1. Open Bloxstrap.
2. Go to Engine Settings.
3. Scroll down and click Fast Flag Editor.
4. Click Add New, then Import JSON.
5. Copy everything from your flags.json, paste it into the input box, and click OK.
6. Launch Roblox.

Warning

Roblox now enforces a strict allowlist for client configuration. Using Fast Flags outside this list has no effect and may be considered client modification, which can lead to account bans.

The Fast Flag Editor is disabled in Bloxstrap 2.10.0+, and using modified clients or unofficial patches is not recommended.

Proceed at your own risk if you’re using older versions.