Convert ICO to PNG — Free ICO to PNG Converter

How to Convert ICO to PNG

Why Convert ICO to PNG?

ICO files are Windows icon containers that hold multiple image sizes for desktop icons and favicons. Converting ICO to PNG extracts the highest-resolution image and gives you a standard format that works everywhere — in design tools, web pages, and presentations.

PNG preserves the transparency that icons typically require. The converted image maintains crisp edges and clean transparency, making it ready for use in designs, documentation, or anywhere you need the icon as a regular image.

LeanImg picks the largest, highest-quality image out of the ICO container and writes it as a PNG — all inside the browser page, with the icon file staying on your machine throughout. Free, and no account exists.

Compress the PNG afterward if size matters. For web favicons, you might want to resize the output to standard sizes like 32x32 or 64x64 pixels.

Compress your PNG · PNG to WebP

What changes going from ICO to PNG

The choice of image is made by width alone. LeanImg walks every entry in the directory and keeps the widest; colour depth is not consulted, and when two entries share a width the one listed first wins. Entries stored as PNG, which Windows has allowed since Vista, are passed straight to the PNG decoder; bitmap entries are rebuilt from their XOR pixels and AND mask, so a 24-bit or palette icon gets hard 0-or-255 alpha while a 32-bit one keeps its full 8-bit alpha.

The 256-pixel quirk is handled: the directory byte reads zero for that size, but the decoder takes the real dimensions from the embedded bitmap header or PNG header, so a 256 icon comes out 256 by 256, not 0 by 0. The selected image is re-encoded rather than copied, which is lossless but means an embedded PNG's ancillary chunks do not survive; an ICO has no EXIF or profile to lose in the first place.

Expect the PNG to be smaller than the ICO it came from, usually much smaller, since the other sizes and the uncompressed bitmap entries are gone. Don't use this when you need the small hand-drawn sizes or the whole set: there is no way to ask for the 16 or 32 pixel entry, and scaling the large one down is not the same as the artist's version. For the reverse trip, the icon generator builds a multi-size ICO from a PNG.

ICO vs PNG

What is a PNG file?

PNG became a W3C Recommendation in October 1996, designed after Unisys began enforcing the LZW patent that GIF relied on. It is lossless and only lossless: one compression method, deflate, applied after per-scanline filters. Every tool advertising a lossy PNG is really quantizing to a 256 color palette before writing an ordinary lossless PNG. Transparency comes in three grades: a real alpha channel at 8 or 16 bits, up to 256 alpha levels from a palette table, or a single keyed color.

How to open a PNG file

Nothing needs installing anywhere: Preview and Quick Look on macOS, Photos and Paint on Windows, and libpng as a base dependency on Linux mean GIMP, Krita and every GTK or Qt application read it. The interesting tools are the optimizers — optipng, oxipng and zopflipng rewrite the file losslessly, and LeanImg's compressor runs oxipng at optimization level 3 without ever changing a pixel.

Convert other formats to PNG

Frequently Asked Questions