ICO to BMP Converter

How to Convert ICO to BMP Online

1. Upload Your ICO File: Drag and drop or click "Add Files" to select Windows icon files. Multi-resolution ICOs that bundle 16×16, 32×32, 48×48, 64×64, 128×128, and 256×256 layers are accepted. Batch is supported — drop in a whole \System32 extract or icon library.
2. Pick Bit Depth and Compression Type: Choose 1-bit (monochrome), 8-bit (256-color indexed), or 16-bit color depth. Set the BMP compression type — None (uncompressed RGB, the most compatible) or Deflate for a smaller file. BMP is lossless; the layered ICO frame closest to your target size is unpacked into a single bitmap.
3. Resize and Set DPI (Optional): Pick a resolution preset, scale by percentage, or set custom width × height in pixels. Set DPI from 72 / 96 (screen) up to 150 / 200 / 300 / 600 / 1200 (print). Color palette size (2 / 4 / 8 / 16 / 32 / 64 / 128 / 256 colors) lets you generate indexed-color BMPs that mimic the original ICO palette exactly.
4. Convert and Download: Click Convert. Files convert on our servers and download individually or as a ZIP — no sign-up, no watermark.

Why Convert ICO to BMP?

ICO is Microsoft's container format for application and shortcut icons — a single .ico file holds several bitmap layers at different sizes and color depths so Windows can pick the right one for the taskbar, desktop, file explorer, or Alt-Tab UI. BMP is the underlying flat-bitmap format Windows has shipped since 1990. Converting ICO → BMP unpacks one of those embedded layers into an editable, single-image bitmap.

• Editing icon artwork in legacy Windows tools — Paint, IrfanView, classic Photoshop plugins, and old MFC-era image editors read BMP natively but choke on the multi-layer ICO container. Convert to BMP, edit pixels, then re-pack with BMP to ICO when done.
• Image processing pipelines and OCR — OpenCV, ImageMagick scripts, Tesseract, and most computer-vision libraries expect single-frame inputs. BMP is the lowest-common-denominator lossless format — no codec surprises, no alpha quirks, no multi-page weirdness.
• Embedded systems and microcontroller displays — STM32 / ESP32 graphics libraries, e-paper drivers, and old printer firmware ship BMP parsers but rarely an ICO decoder. Flashing a splash screen or UI sprite usually means a 24-bit BMP.
• Reverse-engineering icons from .exe / .dll extracts — Tools like Resource Hacker dump icons as ICO. Converting to BMP gives you a flat raster you can diff, archive, or feed into asset-tracking workflows.
• Print and large-format reproduction — Blowing up a 256×256 ICO layer for sticker or signage print is easier from a fixed-DPI BMP than from the layered original. Set DPI explicitly and the printer driver behaves predictably.
• Preserving exact pixel data without compression — Unlike JPG or even PNG, uncompressed BMP stores raw RGB bytes. For pixel-art icons, dithered 8-bit palettes, and forensic image work, that bit-for-bit fidelity matters.

ICO vs BMP — Format Comparison

ICO Layer Sizes — Which One Becomes Your BMP?

Frequently Asked Questions

Which icon layer gets converted when an ICO has several sizes inside?

The converter decodes the first entry in the icon directory — often the smallest layer (for example 16×16), not the largest — and any resolution you set scales that one image rather than selecting a different layer. To convert a specific layer at full quality, export it from an icon editor as a single-size ICO (or as PNG) first, then convert that file to BMP; repeat per layer if you need every size.

Will transparency from the ICO survive in the BMP?

Partially. ICO uses either a 1-bit AND mask (hard edges) or a 32-bit alpha channel (soft edges, Vista+). BMP can carry 32-bit RGBA via the BITMAPV4HEADER, but many older Windows tools — including classic Paint pre-Windows 7 — render the alpha channel as solid black or white. If your target reader is one of those legacy tools, flatten transparency to a chosen background color before converting.

Why is my BMP so much larger than the original ICO?

ICO files compress their large layers (typically the 256×256 frame) as PNG inside the container. BMP defaults to uncompressed raw pixels: a 256×256 24-bit BMP is roughly 196 KB regardless of content. Use Deflate compression to shrink the BMP, or drop bit depth to 8-bit (256-color) for icons that only use a small palette — that alone cuts size by two-thirds.

Should I pick 8-bit, 24-bit, or 32-bit BMP?

8-bit (256-color indexed) is best for classic pixel-art icons, monochrome glyphs, and palette-locked artwork — smallest file, exact color match. 24-bit RGB is the safe default for any modern icon with gradients or photographic content. 32-bit RGBA preserves the alpha channel but only matters if the consumer actually reads alpha (modern editors yes, embedded firmware usually no).

Can I convert a Windows favicon (favicon.ico) to BMP?

Yes — favicons are standard ICO files, just typically 16×16 and 32×32 layers. Drop the favicon.ico in and the converter unpacks one of the embedded frames as a BMP. Note that some modern favicons are PNG-encoded inside the ICO container; that's handled transparently. For the reverse direction (e.g., turning artwork back into a favicon), see BMP to ICO.

Does the converter handle ICO files extracted from .exe and .dll files?

Yes — icons dumped from executables by Resource Hacker, IconViewer, or similar tools are normal ICO files and convert the same way. If the dumped file is a .icl (icon library) instead of .ico, extract the individual icons first; .icl is a different container format.

Why convert to BMP instead of PNG?

PNG is usually better — smaller, lossless, alpha-aware, and universally supported. Pick BMP when your target tool specifically demands it: legacy Windows imaging code, embedded display libraries that ship a BMP-only parser, certain CNC / laser engraver workflows, or forensic / archival pipelines that mandate raw-pixel uncompressed storage. For everything else, ICO to PNG is the better choice.

Can I batch convert hundreds of ICO files at once?

Yes — drop in entire icon archives, .exe extract folders, or theme bundles. Each file converts in parallel on our servers and downloads individually or as a single ZIP. Settings (bit depth, DPI, target resolution) apply uniformly across the batch.