PNG to ICO converter

PNG → ICO packages one source icon into Windows-style favicon sizes instead of making a single resized PNG.

Converted with Image engine · nothing stored
Free: 5 conversions a day · 5 MB each
Higher limits →

From real runs

What you get — and what changes

Element	Result	What happens
Icon sizes	Changed	The ICO contains generated 16, 32, 48, and 256 px renditions from the source PNG.
Alpha channel	Kept	Transparent and semi-transparent PNG edges remain transparent in the ICO entries.
Canvas shape	Kept	Square source art maps cleanly to icon sizes; non-square art is resized into square entries and can look padded or squeezed.
Fine detail	Changed	Small entries such as 16 px necessarily simplify text, thin strokes, and detailed illustrations.
Large source quality	Kept	A square source at least 256 px wide gives the largest ICO entry enough pixels before downscaling.
PNG metadata	Lost	The ICO is an icon container; do not expect PNG text metadata to be preserved.

Icon sizes Changed
The ICO contains generated 16, 32, 48, and 256 px renditions from the source PNG.
Alpha channel Kept
Transparent and semi-transparent PNG edges remain transparent in the ICO entries.
Canvas shape Kept
Square source art maps cleanly to icon sizes; non-square art is resized into square entries and can look padded or squeezed.
Fine detail Changed
Small entries such as 16 px necessarily simplify text, thin strokes, and detailed illustrations.
Large source quality Kept
A square source at least 256 px wide gives the largest ICO entry enough pixels before downscaling.
PNG metadata Lost
The ICO is an icon container; do not expect PNG text metadata to be preserved.

Sample conversions

Product favicon

Input: A 1024×1024 transparent PNG mark with a simple two-color glyph and no text.
Output: A favicon.ico containing 256, 48, 32, and 16 px entries. The 16 px glyph stayed recognizable.

Detailed app illustration

Input: A 512×512 PNG illustration with thin lines, shadows, and small letters inside the mark.
Output: A multi-size ICO where the 256 px entry looked close, but the 16 px entry lost most lettering detail.

Wide logo PNG

Input: A 1200×400 transparent wordmark PNG intended for a website header.
Output: An ICO that looked too small inside square icon slots. Cropping a square mark first produced a better favicon.

A real PNG → ICO run

We converted our PNG sample (20 KB) with Image engine on 2026-10-20. It took 116 ms and produced a 12 KB ICO file, 43% smaller than the input. The engine raised 1 warning, listed below.

Input · sample.png · 20 KB

1200 × 800 px, 8-bit, colour type 6

Width: 1,200
Height: 800
Encoding: 8-bit, colour type 6

Output · sample.ico · 12 KB

256 × 171 px, 1 size: 256×171

Width: 256
Height: 171
Encoding: 1 size: 256×171

Image metadata stripped from output.

Options and when to change them

width: Resize the source before ICO generation only if you need to normalize a very large square PNG.
height: Use with width to keep the pre-ICO source square; mismatched dimensions are a warning sign for favicon art.

Do it yourself

ImageMagick 7

bash

magick in.png -define icon:auto-resize=256,48,32,16 favicon.ico

Start with a square source; automatic resizing cannot redesign detailed art for 16 px.

Pillow 11

bash

from PIL import Image

Image.open("in.png").save("favicon.ico", sizes=[(256, 256), (48, 48), (32, 32), (16, 16)])

Inspect the smallest entry manually; icon downscaling can make thin marks disappear.

PNG to ICO by API or MCP

The HTTP API and the MCP server run the exact engine this page uses (Image engine); the response carries the same warnings the web converter shows. Check support first with GET /api/v1/pairs?from=png&to=ico.

curl

curl -X POST https://filetypeconverters.com/api/v1/convert \
  -H "Authorization: Bearer $FTC_API_KEY" \
  -F "file=@input.png" -F "from=png" -F "to=ico" \
  -F 'options={"dpi":96}' \
  --output output.ico

Options this engine accepts for PNG → ICO

Key	Applies to	Type	Default
dpi	Reading PNG	number	96
width	Writing ICO	number	0
height	Writing ICO	number	0
fit	Writing ICO	contain · cover · fill	contain
quality	Writing ICO	number	90
background	Writing ICO	string	#ffffff
stripMetadata	Writing ICO	boolean	true

API reference

When this is the wrong conversion

Use SVG favicons for modern browsers when vector scaling is more important than old Windows ICO support.
Redraw a simplified 16 px icon if the source contains text or fine strokes.
Use PNG assets directly for iOS or Android icons that require specific separate sizes and manifest entries.

PNG to ICO questions

What PNG size should I start with for ICO?

Use a square PNG at least 256×256. Larger square sources are fine; tiny or rectangular sources make weak icon entries.

Does PNG → ICO keep transparency?

Yes. Alpha from the PNG is preserved in the generated icon sizes.

Why does my favicon look bad at 16 px?

Downscaling cannot preserve small words or thin detail. Favicons usually need a simplified mark for the smallest size.

Does the ICO contain multiple images?

Yes. This conversion creates 16, 32, 48, and 256 px entries inside one ICO file.