Convert BMP to ICO
Turn your BMP images into professional Windows icons. Create multi-size ICO files with transparency – perfect for software, websites, and branding.
ToFormat — free online converter
Upload your files
Max file size: 30MB · Up to 20 files at once
Why ToFormat?
Multi‑Size ICO Creation
Generate icons with all standard sizes (16×16 to 256×256) from a single BMP. Windows automatically picks the right size for each context.
Transparency Support
ICO supports 1‑bit and 8‑bit transparency. If your BMP has an alpha channel (rare), we preserve it. For BMP without alpha, you can set a transparent color.
Batch Icon Conversion
Upload up to 20 BMP files and convert them all to ICO at once. Download individual icons or a ZIP archive.
About the Formats
🖼️ What is BMP?
BMP (Bitmap) is a raster graphics format developed by Microsoft. It stores pixel data uncompressed (usually), resulting in large files but exact fidelity. It's the simplest format, supported everywhere, but impractical for web use due to size.
All BMP conversion tools →🖍️ What is ICO?
ICO (Icon) is the native icon format for Windows. It can contain multiple images of different sizes and color depths (including 1‑bit, 4‑bit, 8‑bit, 24‑bit, 32‑bit with alpha). ICO files are used for program icons, favicons, and file type associations.
All ICO conversion tools →How to Convert
Upload your BMP
Click or drag and drop your BMP files. You can select up to 20 at once.
Set ICO options
Choose output sizes (e.g., all standard sizes or custom). Enable transparency if needed (color key or preserve alpha).
Download ICO
Your ICO files are ready. Download individually or as ZIP. Files auto‑delete in 10 minutes.
When to Convert BMP to ICO
💻 Windows Applications
Create professional icons for your Windows software. Use BMP as source and output multi‑resolution ICO files for taskbar, start menu, and file explorer.
💡 Need PNG for macOS? Try PNG to ICO →🌐 Website Favicons
Generate favicon.ico from your BMP logo. Include multiple sizes (16, 32, 48) for compatibility with all browsers and devices.
💡 Also try JPG to ICO →📁 File Type Icons
Design custom icons for file associations or folders. Convert BMP to ICO and apply them in Windows properties.
💡 Need transparency? BMP to PNG first →🔄 Legacy Icon Conversion
Have old BMP logos or graphics? Convert them to ICO to use as desktop icons or in older software that requires ICO format.
💡 Back to BMP: ICO to BMP →Format Comparison
| Format | BMP | ICO |
|---|---|---|
| Compression | Lossless | Lossless |
| Transparency | No | Yes |
| File Size | Larger | Larger |
ICO is specifically for icons. For other purposes, consider BMP to PNG (web graphics) or BMP to WebP (modern web).
💡 Pro Tips
- Always include a 256×256 version in your ICO for high‑DPI displays. Windows will scale down if needed, but having a native large size looks best.
- For maximum compatibility with older Windows (XP), include 16×16, 32×32, and 48×48 in 4‑bit and 8‑bit color depths.
- If your BMP has no transparency, you can set a specific color to become transparent in ICO using the transparent color picker.
- ICO files can be compressed using PNG compression inside the container (Windows Vista+). We support that option for smaller files.
- Convert in batch mode – upload multiple BMPs and download all ICOs as a ZIP archive. Perfect for icon sets.
- We strip metadata by default for privacy. ICO doesn’t store EXIF anyway.
- For photos, ICO is not suitable (too small). Use BMP to JPG for photos.
How BMP to ICO Conversion Works
BMP stores raw pixel data, making it a perfect lossless source for icon creation. ICO is a container that can hold multiple images (different resolutions and bit depths). When you convert, our server decodes your BMP and generates a set of icon images at the sizes you request. Each size is encoded with the appropriate color depth (e.g., 32‑bit for modern icons, 8‑bit for older systems). The resulting images are packed into a single ICO file.
All processing is done in memory, and your files are permanently deleted after 10 minutes.
BMP vs ICO: Key Differences
Purpose: BMP is a general‑purpose image format; ICO is specifically for icons (shortcuts, favicons, application symbols).
Multi‑image support: BMP stores one image; ICO can store multiple sizes and color depths in one file.
Transparency: BMP rarely supports alpha; ICO supports 1‑bit (on/off) and 8‑bit (partial) transparency via alpha channel in 32‑bit versions.
Compression: BMP is usually uncompressed; ICO can use PNG compression for smaller files (Windows Vista+).
When to Convert BMP to ICO
Convert BMP to ICO whenever you need a Windows icon – for your desktop, a program shortcut, or a website favicon. Use a high‑quality BMP as source to ensure sharp details at all sizes. If your design includes transparency, ICO will preserve it. Always keep the original BMP for editing, as ICO is a delivery format.
Our ICO to BMP converter lets you extract the largest image back to BMP if needed.