ICO Converter

Purpose-built for developers and designers who need Windows ICO icons from raster images. This tool accepts JPG or PNG inputs and outputs an ICO file containing several common sizes for favicon and app assets. By standardizing input validation and encoding, it ensures that icons render consistently across browsers and Windows environments. Users include web teams, CMS admins, and software engineers preparing distribution-ready icons for websites, desktop apps, and installer manifests.
The conversion process embeds multiple size images into a single ICO file, preserving transparency where available and selecting appropriate color depth per size. It follows the Windows ICO format, including image and directory entries for each size, so the resulting file is usable as a favicon, taskbar icon, or launcher asset. Conceptually, images are rendered to target dimensions (e.g., 16x16, 32x32, 64x64, 128x128) and then packed in a single container with correct metadata.
Advanced workflows include batch processing for several inputs, optional ZIP exports, and controllable quantization to balance quality and file size. The tool handles invalid inputs gracefully, reports encoding errors with codes, and ensures the output ICO adheres to platform expectations. Use cases include updating website favicons, provisioning icons for Windows installers, and supplying consistent icons across multi-platform releases.