ICO Converter
Builds a multi-resolution .ico from an image, or unpacks the images inside an existing .ico.
An .ico is not an image format but a container: several sizes in one file, stored two different ways depending on which size they are. This builds one from a piece of artwork, and opens one that already exists — including the palettised entries a Windows resource compiler wrote twenty years ago.
Container
Sizes
Drop the artwork
At least 256×256. It is fitted into each square with transparent margins rather than cropped — a favicon is often the only place the whole mark appears.
How to use it
Choose the direction
Make an icon file, or open one and get every entry back as a PNG plus a zip of the lot.
Pick .ico or .icns
Windows takes the .ico; macOS takes the .icns, and the .icns written here includes the retina types (ic11–ic14) that make an icon crisp in the Dock.
Drop artwork of at least 256×256
It is fitted into each square with transparent margins rather than cropped — a small icon is often the only place the whole mark appears.
Common questions
Why are small entries not PNG?
PNG entries were only understood from Vista onwards, and a 16×16 PNG entry still renders as a black square in some shell surfaces. Below 256 the entry is written as an uncompressed Windows DIB; at 256 a DIB would be 256 KB against a few KB of PNG, so that one is PNG.
Can it open an .icns?
It writes one but does not unpack one. The older entry types inside an .icns are RLE-compressed in a format that needs its own decoder, and shipping half a reader would be worse than saying so.
Do I still need favicon.ico in 2026?
Yes, because browsers request it from the site root whether you declare it or not — leaving it out buys a 404 on every cold visit. It is the one file the modern PNG set does not replace.
Feed it from
Favicon Generator
Produces the whole favicon set — ICO, PNGs, Apple touch icon, web manifest — plus the HTML to paste.
PNG Compressor
Quantises the palette and rewrites the deflate stream to shrink a PNG without changing its dimensions.
JPEG Compressor
Re-encodes a JPEG at a chosen quality with a live before/after size and a difference view.
WebP Converter
Converts images to or from WebP, with a quality slider and lossless mode.
Next
These accept what this tool produces, so the result can go straight in.
Favicon Generator
Produces the whole favicon set — ICO, PNGs, Apple touch icon, web manifest — plus the HTML to paste.
Image Resizer
Resizes by pixels, percentage or a target longest edge, with aspect-ratio lock and batch presets.
PNG Compressor
Quantises the palette and rewrites the deflate stream to shrink a PNG without changing its dimensions.
Background Remover
Keys out a flat or single-colour background in OKLab and returns a transparent PNG, with a brush for fixing the edges.
EXIF Remover
Strips camera, GPS and editing metadata from photos while leaving the pixels untouched.
HEIC Converter
Converts iPhone HEIC/HEIF photos to JPEG or PNG, keeping or dropping the original metadata.