ERF to CUR Converter

CUR is the cursor image format for Microsoft Windows, structurally nearly identical to the ICO (icon) format but with the addition of a hotspot coordinate that identifies the precise pixel position where mouse clicks register. Introduced with early Windows versions, CUR files use the same container structure as ICO: a directory header listing one or more image entries, each specifying dimensions and color depth, followed by the pixel data for each variant. Like ICO, a single CUR file can contain multiple images at different sizes and color depths, allowing Windows to select the most appropriate cursor image for the current display resolution and color settings. Image data within CUR files can be stored as BMP pixel arrays (for legacy compatibility) or as embedded PNG images (supported since Windows Vista) for alpha-blended cursors with smooth edges. The hotspot coordinate — the distinguishing feature separating CUR from ICO — is stored as an X,Y pair in the directory entry header, typically pointing to the tip of an arrow or the center of a crosshair. One advantage is multi-resolution packaging: a single CUR file provides appropriate cursor imagery across display densities from standard DPI to high-DPI screens. Native Windows integration is another strength — CUR files are loaded directly by the operating system for mouse cursor display without any third-party software. CUR files are used by application developers and theme creators to customize the pointing experience across Windows environments.