Image to .ICO Converter

Convert PNG, JPG, WebP, or SVG graphics into true multi-resolution .ico icon binaries or inspect embedded icon layers in your browser.

Icon layer extracted
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Browser Favicons

Create true multi-layer favicon.ico files with crisp 16×16 and 32×32 layers for website tabs and bookmarks.

Tab & Bookmark Sharpness
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Windows App Packaging

Bundle 48×48, 128×128, and 256×256 resolutions into desktop shortcut icons for Windows 10 & 11 applications.

Taskbar & Desktop Ready
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Built-in Layer Inspector

Drop any existing .ico file to examine embedded sub-frames, check colour depths, and extract layers as individual PNGs.

Inspect & Extract Sub-Layers
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100% In-Browser Privacy

Brand assets and trademarked logos never leave your computer. The entire binary compilation runs locally.

Zero server uploads

📋 How to Make a Multi-Resolution .ICO File

  1. 1
    Upload Source Graphic Drag and drop any PNG, JPG, WebP, or SVG logo (square 1:1 image recommended) or paste with Ctrl + V.
  2. 2
    Select Icon Resolutions Tick the resolutions you need (from 16×16 for browser tabs up to 256×256 for high-DPI desktop apps). All standard sizes are pre-selected by default.
  3. 3
    Generate & Download Click Generate & Download Multi-Layer .ICO. Your binary file is assembled and downloaded in under a second.
  4. 4
    Inspect Anytime Switch to the Inspect / Verify tab to verify that any existing .ico has all expected layers and export them as standalone PNGs.

💡 Tips for Perfect Favicons & Icons

Use Transparent PNG or SVG Start with a transparent background so your icon looks sharp in both light and dark browser modes and against dark Windows taskbars.
Keep 16×16 Legible Tiny 16×16 browser tab icons can't show fine text. Use simple, bold geometric symbols or a clean lettermark rather than a complex illustration.
True Binary Multi-Resolution Unlike primitive converters that simply rename a PNG, this tool generates a true Microsoft ICONDIR file with separate frames for every screen size.
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Under the Hood: Microsoft ICONDIR Binary Architecture & Low-Level Buffers

ArrayBuffer binary packaging, ICONDIRENTRY structs, and 32-bit RGBA bitstreams.

Details

Binary ICONDIR Specification

The generator builds compliant Microsoft Windows Icon (ICO) formats by compiling a 6-byte ICONDIR header followed by an array of 16-byte ICONDIRENTRY structs using low-level JavaScript ArrayBuffer and DataView APIs.

High-Precision Bicubic Resampling

Images are proportionally rendered to individual canvases with bicubic interpolation (imageSmoothingQuality = 'high') and encoded as standard uncompressed PNG bitstreams within the file offset tables.

Standard Icon Layer Specifications

Icon Size Standard Target Colour Depth Encoding Standard Alpha Transparency
16 × 16 px Browser Tab Favicon & Address Bar 32-bit (RGBA) PNG Stream Full Alpha Channel
32 × 32 px Taskbar, Bookmarks & File Explorer 32-bit (RGBA) PNG Stream Full Alpha Channel
48 × 48 px Windows Desktop Shortcut Icons 32-bit (RGBA) PNG Stream Full Alpha Channel
64 × 64 px High-DPI Displays & Control Panel 32-bit (RGBA) PNG Stream Full Alpha Channel
128 × 128 px macOS QuickLook / Medium App Tile 32-bit (RGBA) PNG Stream Full Alpha Channel
256 × 256 px Windows 10/11 Extra-Large & Store Apps 32-bit (RGBA) PNG Stream Full Alpha Channel

❓ Frequently Asked Questions

Why do I need multiple resolutions inside a single .ico file?

Different contexts require different icon sizes. Browsers display 16×16 icons on small tabs and 32×32 on high-resolution displays. Operating systems scale desktop shortcuts up to 48×48 or 256×256. Having all resolutions pre-rendered in a single file prevents fuzzy automatic browser downscaling.

Is transparent background preserved during conversion?

Yes. When using a transparent PNG or SVG source image, the 32-bit RGBA alpha channel is preserved across all generated resolutions, allowing transparent backgrounds to render cleanly against light and dark browser themes.

How does the .ICO Inspector tool work?

The Inspector parses the binary directory header of any existing .ico file, verifies its entry table, and decodes each embedded image sub-frame so you can view, inspect, and individually extract sub-layers as standalone PNG files.

Are my graphics or logos uploaded anywhere?

No. All image processing, canvas scaling, and binary byte packing happen 100% locally in your browser memory. Your files are never uploaded or stored.