Unpack Multi-Resolution ICO Favicons into Transparent PNGs
Extract embedded resolution frames from Windows ICO favicon containers into clean 32-bit transparent PNGs locally in browser RAM.
Drop ICO here, or choose files
Convert your ICO files locally in browser memory
Binary Directory Extractor
Unpacking multi-resolution Windows ICO directory headers into clean transparent PNGs
Favicon files (.ico) are composite binary containers that pack multiple embedded image resolutions (such as 16x16, 32x32, 48x48, 64x64, and 256x256 pixels) into a single file header structure. When developers or designers try to edit an `.ico` file in standard photo editing tools, the software usually opens only the smallest 16x16 pixel thumbnail or fails to parse the directory block entirely. Zapixal includes a custom C-compiled WASM binary reader that parses the ICONDIR and ICONDIRENTRY headers, extracting all embedded resolution layers into individual 32-bit transparent PNG assets.
Decompressing embedded PNG and DIB bitmap frames in browser RAM
Modern ICO files contain a mix of uncompressed Device-Independent Bitmaps (DIB) and PNG-compressed streams. Zapixal’s decoder inspects magic byte signatures (0x89504E47 for PNG or XOR/AND bitmask arrays for DIB) to reconstruct true RGBA transparency layers accurately. Because decoding runs client-side inside your browser sandbox, proprietary web application favicons and desktop app icons are extracted securely without uploading your files.
Step-by-step guide
- Drag your `.ico` favicon file into the binary reader workspace.
- View all detected resolution layers unpacked from the icon directory.
- Download your desired resolution or export all frames as high-resolution transparent PNGs.
Frequently Asked Questions
What is inside a standard .ico favicon file?
An .ico file contains a directory header followed by multiple image frames in varying pixel dimensions (from 16x16 to 256x256) used by operating systems for display flexibility.
Does extracting a PNG from an ICO preserve transparency?
Yes. Unpacked PNG assets retain full 8-bit alpha transparency and anti-aliased edge smoothing.
Is my favicon file uploaded to any remote server during extraction?
No. Zapixal parses the binary ICO file structure locally in your browser’s memory.
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Why use Zapixal
Fast browser-based tools engineered for privacy, performance, and day-to-day workflow tasks.
Image compression, PDF manipulation, and developer parsing run locally in browser memory via WebAssembly and Web Workers.
No desktop applications or account signups required. Load the tool and process files immediately with full batch capabilities.
From HEIC conversions and PDF merges to JWT inspection and text diffing, access all essential tools in one clean environment.