How do I convert a PNG to an ICO file?

By IconToGo

Published: 2026-10-04

Short answer: Do not rename .png to .ico. Export the PNG into an ICO that contains several square sizes (16, 32, 48, 64, 128, and 256). Windows and browsers then pick the size they need from that one file.

A single PNG icon beside an ICO file that holds the same icon at 16, 32, 48, and 256 pixels.
Renaming .png to .ico does not add those sizes. The ICO has to contain them.

Why a PNG is not already an ICO

A PNG is a single image. An ICO file is a container: it stores the same icon at more than one pixel size. A site favicon and a Windows shortcut both look for those sizes. Changing the file extension leaves the bytes as a PNG, so the icon looks blank or blurry.

Start from a square PNG at least 256×256. A 512×512 source stays sharper when it is scaled down. Transparency can be kept, because each size is stored as a PNG frame inside the ICO.

What to do

  1. Open PNG to ICO and drop the PNG in. The file stays in your browser and is not uploaded.
  2. Leave the sizes checked: 16, 32, 48, 64, 128, and 256.
  3. Download the .ico. If you are making a site icon, also take the favicon pack and the <link> snippet from the same page.

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PNG to ICO · Favicon Generator · JPG to ICO · All posts