SA-GS is a training-free method for anti-aliasing in 3D Gaussian Splatting (3DGS). Unlike Mip-Splatting, which requires modifying the training process, SA-GS operates during testing and maintains scale consistency using a single 2D scale-adaptive filter. This filter ensures that Gaussian scales remain consistent across different rendering settings, addressing the issue of Gaussian scale mismatch that causes visual artifacts in 3DGS. SA-GS also incorporates super-sampling and integration to enhance anti-aliasing performance. The method is applied as a plugin to any pretrained 3DGS model, significantly improving its anti-aliasing capabilities. Extensive experiments on the Mip-NeRF 360 and Blender datasets show that SA-GS performs comparably or better than Mip-Splatting, particularly in zoom-out scenarios. The method is training-free, flexible, and more efficient than existing approaches. SA-GS ensures consistent Gaussian projections and effectively reduces aliasing effects, making it a superior solution for anti-aliasing in 3DGS.SA-GS is a training-free method for anti-aliasing in 3D Gaussian Splatting (3DGS). Unlike Mip-Splatting, which requires modifying the training process, SA-GS operates during testing and maintains scale consistency using a single 2D scale-adaptive filter. This filter ensures that Gaussian scales remain consistent across different rendering settings, addressing the issue of Gaussian scale mismatch that causes visual artifacts in 3DGS. SA-GS also incorporates super-sampling and integration to enhance anti-aliasing performance. The method is applied as a plugin to any pretrained 3DGS model, significantly improving its anti-aliasing capabilities. Extensive experiments on the Mip-NeRF 360 and Blender datasets show that SA-GS performs comparably or better than Mip-Splatting, particularly in zoom-out scenarios. The method is training-free, flexible, and more efficient than existing approaches. SA-GS ensures consistent Gaussian projections and effectively reduces aliasing effects, making it a superior solution for anti-aliasing in 3DGS.