OptiScaler expands FSR 4 beyond DirectX 12 with a new Vulkan interop mode
We have not heard much from the AMD Radeon team for quite some time, and it looks like they have been focused on adding AI bundles to the drivers. Meanwhile, modders have been working on features gamers haveactully been asking for, including FSR 4 support for Vulkan games.
It is hard to believe, but despite launching FSR 4 months ago, this upscaling technology still does not work with Vulkan titles. AMD has not confirmed that Vulkan support is planned, but it has been a widely requested feature.
The good news is that a test build of OptiScaler is being shared on Reddit with a changelog line claiming “Added Vulkan w/Dx12 support, FSR4 VK w/Dx12, FSR 2.1 VK w/Dx12.” The post was published on February 23, 2026, and points to a “v0.9.0-pre10 Test Build.”
OptiScaler NEW VERSION called “v0.9.0-pre10 Test Build” brings FSR4 to vulkan.
The new changelog states:
Added Vulkan w/Dx12 support – FSR4 VK w/Dx12, FSR 2.1 VK w/Dx12
Optiscaler
OptiScaler is a middleware-style mod that hooks a game’s upscaler interface and redirects it to a different backend, letting users swap between supported upscalers where a game already exposes compatible inputs. The project documentation includes a warning against using the mod in online titles due to anti-cheat risk.
This matters because AMD’s own FSR 4 “driver upgrade” path has explicit API limits. In September 2025, AMD said its FSR 4 driver upgrade feature applies to DirectX 12 games that integrate a signed FSR 3.1 DLL, however it is not compatible with FSR 3.1 titles that run on Vulkan.
© Optiscaler Running Vulkan through DX12
What OptiScaler appears to be doing is adding an interop mode where Vulkan titles can use a DirectX 12-only upscaler backend by running the upscaler through a DX12 path. A related GitHub Actions run from February 7, 2026 is titled “Added FSR2.1.2 w/Dx12 to Vulkan upscalers,” which lines up with the “Vulkan w/Dx12” phrasing that surfaced in the Reddit changelog excerpt.
This is not the same as native Vulkan support inside AMD’s official FSR 4 pipeline, it is a compatibility path, so performance overhead and game-by-game issues are plausible.
For now, the only confirmed public details are the community changelog excerpt and the upstream work visible in OptiScaler’s repository activity. AMD has not published an equivalent Vulkan-ready FSR 4 driver upgrade path, and AMD’s last formal guidance still calls Vulkan incompatible for that feature.
Source: Reddit
Many thanks to Sebastian Castellanos for the tip!
