HQ2x Upscaler

HQ2x is a pixel-art magnification algorithm from the emulator scene (by Maxim Stepin). It compares each pixel with its neighbors and blends similar colors to produce anti-aliased edges, while leaving contrasting colors untouched. The result is smoother than Scale2x but still respects the structure of the art.

Scale2x only copies existing colors, so the palette never changes; HQ2x interpolates, creating in-between shades at soft edges. Use Scale2x when you need an exact palette (e.g. to keep editing the art), HQ2x when you want a smoother finished look.

This page runs a lightweight threshold-blend approximation of HQ2x rather than the original 256-case lookup table. On typical sprites the visual difference is small; for pixel-exact emulator output, use an emulator build with native HQ2x.

Yes — set any scale up to 1000%. The HQ2x pass runs at 2x and the remainder scales with nearest neighbor, keeping edges crisp.