What is the CUR file format?
Files with the .cur extension store static mouse cursor icons used by Windows systems. The format is a binary image container developed by Microsoft, introduced with Windows 1.0 in 1985.
.cur files are structurally near-identical to the .ICO icon format - both use a 6-byte ICONDIR header followed by an array of directory entries and image data. The key difference is the type field in the header (02 00 for cursors vs. 01 00 for icons) and a hotspot stored per directory entry - a pair of X/Y coordinates that tells Windows exactly which pixel of the cursor image acts as the active click point.
Cursor images are typically stored in three variants, each with a different purpose:
- standard usage (the default mouse pointer),
- waiting periods (for example, while opening a file or starting a program - traditionally an hourglass icon),
- text-editing mode (the I-bar icon).
A single .cur file can contain multiple size variants of the same pointer (commonly 32×32 and 48×48 pixels) in color depths from 1 bpp to 32 bpp. Since Windows Vista, entries may also embed compressed .PNG image data internally, reducing file size while preserving quality at larger dimensions. For animated cursors, Windows uses the .ANI format instead - a RIFF-based container that stores a sequence of .cur-style frames with per-frame timing data.
Changing the cursor icon
The default cursor icon saved in .cur files can be changed using desktop themes (distributed as .THEME files). Most desktop themes are available for free. Themes can not only change the mouse pointer icons but also menus, color schemes, sounds, the desktop background, folder icons, and more - making them a popular tool for personalizing Windows desktops.
Windows users can also manually change the mouse cursor icon through Mouse settings in Control Panel (or the Settings app in Windows 10/11) by selecting an alternative icon from an associated .cur file.
Default location
.cur files are by default saved in the Cursors subfolder located in the Windows system folder (typically C:\Windows\Cursors).
Security & safety
RISK: LOWA .cur is image data, not executable code, so a genuine cursor file is safe to open in a viewer or apply as a pointer. Two cautions: (1) historically, bugs in cursor/icon PARSERS (and in the related .ani handler) have been used to crash or exploit Windows, so keep the OS updated; (2) custom "cursor theme" packs from random download sites can bundle installers carrying adware - get cursors from reputable sources and apply the .cur manually rather than running a bundled installer.
Format details
in a nutshell- Multimedia Fusion / other niche tools - A few unrelated programs have reused .cur, but on Windows the extension is overwhelmingly the static cursor format described here.
Programs that open CUR files
Windows5 apps
GIMP
Open-source Open the .cur to view/edit each image; export back to cursor or to PNG. Full free editor. 
Greenfish Icon Editor Pro
Free Free dedicated icon/cursor editor: open, view, edit and set the hotspot of a .cur (and create new ones). 
Microsoft Windows (Settings / Control Panel)
Built-in Settings > Bluetooth & devices > Mouse > Additional mouse settings > Pointers tab > Browse to the .cur to set it as a pointer. No conversion needed. 
macOS1 app
GIMP
Open-source Open the .cur to view/edit; export to PNG. (macOS does not use .cur for its own pointers.) 
Linux1 app
Technical details
deep spec| File type | Static mouse-pointer image container (binary) |
| Developer | Microsoft |
| Magic bytes (hex, offset 0) | 00 00 02 00 - ICONDIR header: 2 reserved bytes followed by type field 02 00 (cursor) |
| Byte order | Little-endian |
| Container structure | 6-byte ICONDIR header, an array of ICONDIRENTRY records (each with hotspot X/Y), and per-entry image data |
| ICONDIR type field | 0x0002 (cursor); distinguishes .cur from .ico, which uses 0x0001 |
| Hotspot | Per-entry X/Y pixel coordinate pair defining the active click point within the cursor image |
| Color depth | 1, 4, 8, 24, or 32 bpp; 32-bit entries include an 8-bit alpha channel |
| Image dimensions | Up to 256×256 px per entry; common pointer sizes are 32×32 and 48×48 px |
| Multi-size support | A single .cur file can store multiple size variants of the same pointer in one directory |
| Compression | None for DIB (bitmap) entries; DEFLATE inside embedded PNG entries (supported since Windows Vista) |
| MIME type | image/x-win-bitmap |
| Default storage path | C:\Windows\Cursors |
| Typical file size | 1-100 KB |
| Animated counterpart | .ani - a RIFF container storing multiple .cur-style frames with per-frame delay/rate timing |
| Released | 1985 (Windows 1.0) |
| Latest version | PNG-compressed cursor entries supported since Windows Vista (2007) |
| Open standard | Yes · royalty-free |
| Specification | learn.microsoft.com |
CUR conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about CUR files.
