BMP to ICO

What is BMP?

BMP (Bitmap) is a raster image format developed by Microsoft for the Windows operating system. It stores pixel data uncompressed or with simple run-length encoding, which makes BMP files easy to decode but usually very large. BMP supports 1-bit, 4-bit, 8-bit, 16-bit, 24-bit and 32-bit colour depths, and can optionally include an alpha channel for transparency. Because BMP is a lossless, uncompressed format, it is sometimes used as an intermediate or archival format for graphics that must not lose any quality.

What is ICO?

ICO is the historical icon container format introduced by Microsoft in 1985 for Windows 1.0. An .ico file is a small container that can hold one or more bitmaps or PNG-compressed images at different sizes (typically 16×16, 32×32, 48×48, 64×64, 128×128, and 256×256) and color depths. Browsers, the Windows shell, bookmark managers, and desktop shortcuts all look for an .ico file (commonly favicon.ico) at the root of a website to display the site's icon.

BMP vs ICO comparison

BMP and ICO serve different purposes: BMP is a single uncompressed raster image, while ICO is a multi-image container designed specifically for favicons and app icons. The table below summarises the key differences.

Feature	BMP	ICO
Format type	Single raster image	Multi-image icon container
Compression	Usually none	BMP or PNG embedded
Typical use	Archival, Windows graphics	Favicons, app icons, shortcuts
File size	Usually large	Small
Multiple sizes	No	Yes

When to use BMP to ICO conversion

Converting a BMP image to an .ico file is the right choice whenever you need a favicon or app icon from a BMP source. Common scenarios include:

• Launching a new website. Place a real favicon.ico at the site root so every browser shows your icon.
• Desktop shortcuts. Windows and many Linux file managers pull the icon from favicon.ico for URL shortcuts.
• Bookmark managers. Tools such as Pinboard and RSS readers request /favicon.ico directly.
• Windows application icons. Many Windows development tools still expect an .ico file for the application icon.
• Brand consistency. Distributing a single .ico file keeps your icon identical across web, desktop, and bookmark channels.

How to convert BMP to ICO

Converting a BMP image to an .ico favicon with this tool takes only a few seconds and happens entirely in your browser. Follow these four steps:

1. Upload your BMP file. Click the upload area or drag and drop a .bmp file.
2. Choose the ICO size. Pick one of 16, 32, 48, 64, 128 or 256 px. 32×32 is the standard favicon size.
3. Convert to ICO. Click the "Convert to ICO" button. The tool draws the BMP onto a square canvas at the chosen size and wraps the PNG bytes inside a single-image .ico container.
4. Download the ICO. Click "Download ICO" to save favicon.ico to your device.