Does this support all BMP variants?

Yes. The browser's native Image element handles standard BMP files including 24-bit and 32-bit variants. The tool reads the decoded pixel data via Canvas API.

Which sizes are included in the output ICO?

Four standard sizes are packed into the file: 16x16, 32x32, 48x48, and 64x64 pixels — the most widely supported icon dimensions.

Is my image uploaded to a server?

No. The entire conversion happens inside your browser using the Canvas API and File API. Your image never leaves your device.

What color depth does the output ICO use?

The tool generates 32-bit RGBA bitmaps, which support full color and transparency (alpha channel).

Can I use the output as a favicon.ico?

Yes. Rename the downloaded file to favicon.ico and place it in your web root. All modern browsers and web servers recognize multi-resolution ICO files.

What if my BMP has a transparent background?

BMP files do not natively support transparency. The tool will render any transparent areas as white in the output ICO unless the BMP uses a 32-bit format with an alpha channel.

BMP to ICO Converter

Upload a BMP image and instantly download a multi-size .ico file (16, 32, 48, 64 px) — no server, no account needed.

Upload BMP

Click to choose a BMP file or drag and drop here

Upload a BMP to see icon previews here

Summary

BMP to ICO Converter is a free, browser-based tool that reads any BMP file you upload, draws it onto hidden canvases at four standard icon resolutions, and assembles the raw bitmap data into a valid .ico binary. The resulting file can be used as a Windows application icon, website favicon, or anywhere ICO format is required. All processing happens locally — your image never leaves your device.

How it works

Click "Choose BMP File" and select any .bmp image from your device.
The tool renders the BMP onto four Canvas elements at 16x16, 32x32, 48x48, and 64x64 pixels.
Each canvas is read as raw RGBA pixel data and encoded as a 32-bit BMP DIB bitmap.
A valid ICO file header is assembled in memory, referencing all four bitmap images.
The finished .ico binary is offered as an instant browser download — no upload, no server.

Use cases

Create a multi-resolution favicon.ico from a BMP logo or artwork.
Package a BMP graphic as a Windows desktop or taskbar icon.
Convert a BMP to ICO for use in Electron or desktop application projects.
Produce a quick icon asset without installing Photoshop or GIMP.
Generate multiple icon sizes from a single source BMP in one step.
Prepare icons for browser extension manifests that require .ico format.
Convert scanned or legacy BMP artwork into modern icon format.

Frequently Asked Questions

Last updated: 2026-05-28 · Reviewed by Nham Vu