Why is my icon blurry after conversion?

ICO is Microsoft's Windows icon container, used since Windows 1.0 in 1985 and still the format for favicons embedded in browser tabs. A single ICO can hold multiple resolutions (typically 16x16 through 256x256) plus colour-depth variants (1-bit through 32-bit with alpha), letting Windows pick the right size for the taskbar, Explorer thumbnails, or the desktop. Web developers grab favicon.ico from any production site and find a Russian-doll bundle of resolutions when they pop it open.

Converting ICO to HEIC extracts a single frame - our converter defaults to the largest, usually 256x256 - and re-encodes it in a modern container. The strongest argument for HEIC over JPG here is transparency: icons are almost always alpha-masked cutouts, and HEIC preserves 8-bit alpha natively while a JPG conversion must flatten against a background colour and produce halos on dark themes. Brand auditors collecting hundreds of competitor favicons get a compact, transparency-intact reference set that Quick Looks and syncs cleanly on Macs and iPads.

The compatibility flip side deserves a moment's thought, because ICO and HEIC sit at opposite ends of the platform world: ICO is a deeply Windows-native format, and HEIC output will not open on a stock Windows machine without the HEVC Video Extensions codec. If the extracted icons are headed for a Windows-authored spreadsheet or a web page, convert them onward with HEIC to JPG (accepting the flattened background) or target PNG-based workflows instead. For Apple-side documents - Keynote, Pages, Notes - the HEIC drops straight in.

Reasons to convert ICO to HEIC usually come down to compatibility, file-size, or specific feature requirements. Common situations:

• An app or platform only accepts HEIC uploads.
• You need a feature unique to HEIC (e.g. transparency, vector scaling, animation, multi-page pages, etc.) that ICO doesn't provide.
• You're optimising file size — modern formats often produce smaller files than the older format you started with.
• You need a single archival format across a project so files behave consistently in the same viewer.

1. Open the ICO → HEIC tool on heic.now.
2. Drag your ICO file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. The output is fixed to HEIC. If the format supports extra options (page size, transparency background, quality, EXIF stripping), tweak them in the right-hand panel.
4. Click Convert. The job runs on our server and finishes in a few seconds for typical photos.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Always take the 256x256 frame from a multi-resolution ICO - the smaller frames are designed for Explorer's tiny render targets and look blurry when upscaled.
• HEIC preserves the icon's alpha channel - no flatten colour needed, and the cutout works on both light and dark slide backgrounds.
• If extracting a favicon, fetch favicon.ico from the site's root - and check the apple-touch-icon link tag for a higher-resolution PNG alternative.
• For competitor research at scale, batch-convert via image-converter rather than one at a time - hundreds of favicons in a single drag.
• ICO files larger than 100KB are usually multi-frame bundles - inspect first in IcoFX or GIMP if you need a specific frame other than the largest.