What sizes does the ICO file contain?

Each ICO output contains six embedded PNG frames: 16×16, 32×32, 48×48, 64×64, 128×128, and 256×256 pixels. Modern Windows and browsers select the best size automatically.

Why convert BMP to ICO?

ICO is the standard format for Windows application icons and browser favicons. BMP files are uncompressed raw bitmaps — converting to ICO packages your image into a multi-size icon container ready for Windows or web use.

Can I convert multiple BMP files at once?

Yes — this tool supports batch conversion. Drop up to 25+ files at once, monitor per-file status, then download individually or as a single ZIP archive.

Does my data get uploaded to a server?

Never. All BMP decoding and ICO encoding happens entirely in your browser using JavaScript. Your images never leave your device.

What software opens ICO files?

ICO files open natively in Windows Explorer (as icons), web browsers (as favicons), GIMP, Photoshop (with a plugin), and most professional image editors.

BMP to ICO Converter

Convert BMP bitmap images to ICO icon files locally in your browser. Each ICO contains six sizes (16–256 px) embedded as PNG frames. Batch convert, preview thumbnails, download individually or as a ZIP. No uploads, no account required.

🖼️

Drop BMP files here

or Browse Files · Multiple files supported

Download as ZIP ZIP named with timestamp · Individual download always available per file

What This Tool Does

Converts BMP bitmap images — the uncompressed Windows bitmap format — to ICO format entirely in your browser. Each ICO output contains six embedded PNG frames at standard icon sizes (16×16, 32×32, 48×48, 64×64, 128×128, and 256×256 pixels). No server upload, no account, no file size limits imposed by a backend.

Who This Is For

Web developers who need a favicon from a BMP logo or graphic
Windows app developers who need an ICO file for application icons from BMP source art
Designers converting legacy BMP assets into multi-size icon files
Anyone who needs a quick ICO from a BMP image without installing software

Example: Input: logo.bmp (Windows bitmap) → Output: logo.ico (multi-size icon, ready for favicon or Windows app use)

💡 Need a web-compatible image instead? Try BMP to AVIF for modern compression. For favicon use on the web, convert to WebP. To resize before converting, use the Image Resizer.

Related Guides & Tutorials

Guide

BMP to ICO: Complete Conversion Guide

What ICO format is, when to use it for favicons and Windows icons, and how to get the best results from BMP source images.

Tutorial

How to Convert BMP to ICO: Step-by-Step

A hands-on walkthrough for converting BMP images to ICO in your browser — batch mode, multi-size output, ZIP download, and more.

Guide

BMP to AVIF Converter Guide

Why BMP is oversized for modern use and when to convert to next-gen AVIF format.

Tool

⬇ Image Resizer

How It Works

Drop your BMP filesDrag one or more .bmp files onto the drop zone, or click Browse Files. Thumbnails generate immediately using the browser's native BMP decoder.

Click Convert to ICOThe browser decodes each BMP to pixel data via Canvas; the ICO encoder scales to six sizes and builds a standards-compliant ICO blob in memory.

Download your ICOsDownload files individually or check "Download as ZIP" for a single timestamped archive. App resets after export.

🔒 Privacy & Security

All decoding and encoding runs entirely in your browser. BMP files are never sent to any server — they stay in your browser's memory from load to download. This is especially important for proprietary graphics, internal brand assets, or client work.

You Might Also Need

BMP to AVIF → Image Resizer → Image Compressor → Image to WebP → DDS to ICO →

BMP vs ICO: Format Comparison

Property	BMP	ICO
Primary use	Windows graphics, legacy applications	Application icons, favicons
Compression	None (uncompressed raw pixels)	Lossless PNG frames (modern)
Typical file size	Very large (1–50 MB)	Small (50–300 KB multi-size)
Multi-size support	No	Yes — multiple frames in one file
Transparency (alpha)	Limited (32-bit BMP only)	Full 32-bit RGBA transparency
Platform support	Windows, most editors	Windows, all browsers (favicon)
Best for	Raw source art, legacy systems	App icons, favicons, Windows UI
Internal format	Raw uncompressed pixel data	PNG or BMP frames embedded

Frequently Asked Questions

What sizes does the output ICO contain?▼

Each ICO file contains six PNG frames: 16×16, 32×32, 48×48, 64×64, 128×128, and 256×256 pixels. Windows and browsers automatically select the most appropriate size for the context.

Can I use the ICO as a favicon?▼

Yes — ICO is the original favicon format. Rename the output to favicon.ico and place it in your website root. All browsers will use it automatically, selecting the most appropriate embedded size.

Can I convert multiple files at once?▼

Yes — drop up to 25 or more files at once. The tool processes them sequentially, shows per-file status badges, and lets you download all ICOs individually or as a single timestamped ZIP.

Does the ICO support transparency?▼

Yes — the ICO frames are encoded as 32-bit RGBA PNG, which supports full alpha channel transparency. If your source BMP has a transparent background (32-bit BMP), it will be preserved in the ICO output.

Is this tool free with no limits?▼

Yes — completely free with no file size limits, no per-conversion limits, and no account required. Processing happens in your browser so we never see your files.

What is the ZIP file named?▼

The ZIP is named dataconversioncenter_bmp_to_ico_YYYYMMDDHHMM.zip using your local time — for example dataconversioncenter_bmp_to_ico_202603061200.zip.