Why would I need ICO instead of BMP?

ICO is the format Windows expects for application icons, desktop shortcuts, and favicons.

Does the source BMP actually have transparency?

Rarely. Most BMP files have no alpha channel. 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.

Diagram showing a BMP file converting into a ICO file inside a browser window

Image guides

How to Convert BMP to ICO in Your Browser

Converting a BMP image to ICO produces a real Windows ICO icon — a single size, or the default multi-size package covering 16 through 256 px. This guide covers the steps and what to know about transparency and file size.

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Open BMP to ICO →

Step-by-step conversion

Open /tools/bmp-to-ico.
Choose a BMP file — the content is validated before conversion, not just the filename or extension.
Select Convert & download.
Save the .ico file from your browser downloads.

Transparency and file size

Each embedded icon size keeps the source’s alpha channel — this is a genuine ICO container (ICONDIR plus one entry per size), with each size embedded as real PNG-compressed image data.

Source-specific behavior

Transparency is kept only when the browser decodes a real alpha channel from the source BMP; most BMP files have no transparency at all.

Privacy

Conversion runs locally in your browser. The file is not uploaded to Looty Tools servers for this workflow.

Convert BMP to ICO FAQ

Why would I need ICO instead of BMP?: ICO is the format Windows expects for application icons, desktop shortcuts, and favicons.
Does the source BMP actually have transparency?: Rarely. Most BMP files have no alpha channel. When the browser does decode real alpha data from a 32-bit source BMP, it is preserved in output formats that support transparency.
Does ICO output keep transparency?: Each embedded icon size keeps the source’s alpha channel — this is a genuine ICO container (ICONDIR plus one entry per size), with each size embedded as real PNG-compressed image data.
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.

Related guides

Open the tool

Jump into BMP to ICO when you are ready to process your files.

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