Convert ICO to PNG

Convert ICO to PNG by choosing what to extract

An icon file commonly holds several pictures. A browser tab may use a 16-pixel entry, File Explorer may request 32 or 48, and a desktop preview may reach for 256. The entries can use different bit depths and different internal formats, and two entries may even have the same dimensions. “Convert ICO to PNG” therefore needs one decision that a simple image converter cannot make honestly: which embedded picture do you want?

This page reads the ICO directory and lists every supported entry with dimensions, bit depth, and payload type. You select one exact entry. It never silently chooses the largest image, because largest is wrong when the job is to inspect the actual small icon or compare how a design changes between sizes. Duplicate dimensions remain separate instead of overwriting one another.

PNG-backed and bitmap-backed entries need different decoding

Modern ICO files often store PNG bytes directly for larger images. Older and smaller entries may use a DIB bitmap plus a transparency mask. Those paths do not agree about row order, alpha, or where the visible height ends. The converter parses the container and decodes the selected payload according to its actual form rather than asking the browser to guess from an .ico filename.

Transparency is preserved when the entry contains it. For traditional entries, the alpha channel and one-bit mask are interpreted together instead of assuming either one is always authoritative. A malformed directory, truncated payload, unsupported compression, or entry that points outside the file produces a named failure and no download.

Extraction is the reverse job, not the same interface backward

The PNG to ICO builder starts with one source image and creates a container containing chosen target sizes. This tool opens an existing container and returns one image that is already inside it. That difference is why the two have separate URLs and controls. A format switch would hide the most important choice on each side.

The first version exports one chosen entry at a time. The ICO stays loaded, so selecting and exporting another entry does not require a new upload or parse. One-at-a-time naming also prevents two same-sized entries from colliding in an automatic batch and disappearing without notice. The completed PNG is reopened to verify its dimensions, transparency, and bytes before download.

Local files only

Choose or drop an ICO from this device. This route does not fetch a favicon URL, crawl a website, or send the container to a conversion service. Directory parsing, entry decoding, PNG writing, preview, and verification happen locally. If the actual task is to inspect a live site's current icon setup, use the favicon checker; URL discovery is a different network job and does not belong inside a private file extractor. Local resource advice may appear for unusually large or malformed containers, but byte size alone is never used as an arbitrary refusal.