What BMP to ICO conversion does

Convert a BMP image to a Windows ICO icon directly in your browser. Generate a single size, or the default multi-size package covering 16, 32, 48, 64, 128, and 256 px in one .ico file.

How to convert BMP to ICO

1. Choose a BMP file.
2. Pick a single icon size, or leave the default multi-size package selected.
3. Select Convert & download.
4. Save the .ico file from your browser downloads.

Why use this conversion

ICO is the format Windows expects for application icons, desktop shortcuts, and favicons. A single square image can be turned into a real, multi-resolution .ico file ready to use.

Transparency and output quality

Each embedded size keeps the source’s alpha channel — this is a real ICO container (ICONDIR plus one entry per size), with each size embedded as genuine PNG-compressed image data, not a renamed bitmap. Each icon entry uses PNG compression, so a single-size ICO stays small; the multi-size package is larger since it bundles six images.

Privacy and local processing

• Processing occurs locally in the browser.
• Files are not uploaded to Looty Tools for conversion.
• Converted files remain on your device.

Limits and known issues

• Input: BMP (.bmp) only, up to 25.0 MB and 8,192 px per side.
• Each icon size is generated by resizing the full image to a square canvas, so a non-square source will be stretched to fit.
• Transparency is kept only when the browser decodes a real alpha channel from the source BMP; most BMP files have no transparency.
• Metadata is not preserved in the downloaded file.

Related tools

• BMP to AnyConvert BMP images into multiple common output formats.
• BMP to TIFFConvert BMP images to TIFF for print and archival use.
• BMP to GIFConvert BMP images to a static GIF.

BMP to ICO FAQ

Why convert BMP to ICO?

ICO is the format Windows expects for application icons, desktop shortcuts, and favicons. A single square image can be turned into a real, multi-resolution .ico file ready to use.

Can I generate a multi-size ICO?

Yes. The ICO output defaults to a multi-size package covering 16, 32, 48, 64, 128, and 256 px, or you can pick a single size from the dropdown.

Is this a real ICO file, or a renamed image?

A real ICO container (ICONDIR plus one entry per size), with each size embedded as genuine PNG-compressed image data.

Does the source BMP actually have transparency?

Rarely. Most BMP files have no alpha channel at all. When the browser does decode real alpha data from a 32-bit source BMP, it is preserved in output formats that support transparency.

Are my files uploaded?

No. Conversion runs locally in your browser and does not upload your file to Looty Tools servers.

What is validated before conversion?

The file must actually be a BMP — the tool checks the "BM" header bytes, not just the filename or extension, before decoding.