Windows Cursor MIME Type Reference
image/x-win-cursor
Released 1985
· by Microsoft Corporation
The Windows Cursor (CUR) file format is a proprietary image format developed by Microsoft for mouse pointers. It is structurally identical to the Windows Icon (ICO) format, with two key exceptions: an identification byte in the header marking it as a cursor rather than an icon, and the inclusion of a 'hotspot'—a specific X and Y coordinate within the image grid that defines the exact point where user clicks are registered.
Technical Specifications
.cur
None (DIB / BMP)Deflate (If PNG embedded)
image/cursorapplication/x-cursorimage/vnd.microsoft.icon
Magic Bytes & HTTP Headers
\x00\x00\x02\x00
Browser Support Matrix
| Browser | Status | Min Version |
|---|---|---|
|
|
Supported | 1 |
|
|
Supported | 1 |
|
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Supported | 1.2 |
|
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Supported | 12 |
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Supported | Legacy |
Advantages & Limitations
- Natively supported by Windows for desktop cursor customization
- Widely supported by modern web browsers for custom CSS cursors
- Supports an exact hotspot coordinate, which standard image formats like PNG and JPEG lack
- Legacy format that is being gradually replaced by SVG and PNG for web implementations
- Does not support animation (animated cursors use the distinct .ani format)
- The MIME type is highly fragmented across systems (e.g., image/cursor, image/x-win-cursor, application/x-cursor)
Developer Code Snippets
File Detection Steps
How to programmatically detect a image/x-win-cursor
file by reading its raw bytes:
- 1 Check the first 4 bytes for the exact hex signature 00 00 02 00.
- 2 Parse the image directory at offset 4 to extract the hotspot coordinates at bytes 4 and 6 of the directory entry.
Software Support
Free Online Tools for CUR
Resize, scale, crop, and modify dimensions for any photo or graphic.
Clean EXIF, camera, lens, and location tags from your photos.
Convert modern web images to universal high-compatibility JPG.
Reduce image file sizes for faster web performance.
CUR Format Comparisons
Share & Embed
[](https://freewebptojpg.com/mime/image/cur)
<iframe src="https://freewebptojpg.com/mime/image/cur/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="CUR Specs"></iframe>
JSON API
All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.
GET https://freewebptojpg.com/mime/image/cur.json
Open JSON
Frequently Asked Questions
What is the magic byte for image/x-win-cursor?
A CUR file always begins with the 4-byte sequence 00 00 02 00 in hexadecimal. The '02' differentiates it from an ICO file, which uses '01'.
Is image/x-win-cursor supported in web browsers?
Yes. Most modern web browsers support .cur files specifically for use within the CSS 'cursor' property (e.g., cursor: url('custom.cur'), auto;).
What is a cursor 'hotspot'?
Unlike a standard image, a cursor must define exactly which pixel triggers a click event. A CUR file stores this precise X and Y coordinate (the hotspot) in its image directory header.