What is an .ico file used for?

ICO is the standard Windows icon format, used for desktop application icons, shortcut icons, and browser favicons. It's a distinct container format from ordinary image files, which is why a plain PNG renamed to .ico won't actually work as an icon.

Does this produce a single icon size, or a full multi-resolution icon set?

A single resolution, matching your uploaded PNG's own size. Windows icons can technically bundle several sizes (16×16, 32×32, 48×48, and so on) in one .ico file for different display contexts — if you need that full multi-size bundle specifically for a website favicon, Favicon Generator builds that complete set; this tool is the simpler, direct single-size conversion.

What PNG size should I use for the best icon?

For a typical desktop application or shortcut icon, 256×256 gives a sharp result at most display sizes, since Windows can scale a large source icon down cleanly. Starting from a smaller PNG works fine too, just with a bit less headroom when the icon is displayed larger.

Will transparency in my PNG be preserved?

Yes — the conversion preserves your PNG's alpha transparency, so a logo or icon with a transparent background converts to an ICO that still shows that same transparency rather than a solid background.

Can I convert several PNGs to ICO at once?

Yes, batch conversion is supported — upload multiple PNG files and download the converted icons individually or together as a ZIP.

Will the ICO file work on Mac or Linux, not just Windows?

The .ico format itself is readable cross-platform by many applications and image viewers, though it's specifically the Windows OS that uses .ico natively for things like desktop shortcuts and application icons — Mac uses its own separate .icns format for that same purpose.

Is my image uploaded to a server for this?

No. The ICO file is built directly in your browser by writing the icon format's real binary structure — your image is never transmitted anywhere.

PNG to ICO

Convert a PNG image into a Windows-compatible .ico icon file.

Processed entirely in your browser. Your file is never uploaded anywhere.

Why convert PNG to ICO with Tools Root

Windows applications, shortcuts, and desktop icons specifically need the .ico format — a plain PNG or JPG won't work as a system icon no matter what it's named. This free PNG to ICO converter builds a genuine, correctly-structured .ico file directly in the browser.

A real icon file, not a renamed image

This writes the actual ICO binary format's header and pixel structure from your PNG's image data, rather than just changing a file extension, which produces a file that genuinely works wherever a real .ico icon is expected.

A free PNG to ICO converter with transparency support

Whether converting a single app icon or a whole batch of image assets, this tool preserves your source PNG's transparency and requires no software install, no account, and no cost.

Common use cases

Converting a logo or app icon design into a working Windows .ico file, preparing a custom shortcut icon from a PNG image, converting a game or software project's icon asset for Windows packaging, building a simple single-size icon for an internal tool, or converting exported design assets into the icon format a build process expects.

Building a full favicon set instead

A website favicon typically wants several icon sizes bundled together for different browsers and devices — that fuller, multi-size case is exactly what Favicon Generator is built for, generating a complete icon set from one source image rather than the single-size conversion this tool provides.

Why PNG alone doesn't work as a Windows icon

Windows icons use a distinct file structure, the .ico format, that's different from a standard image file — an operating system looking for an application or shortcut icon specifically expects that format's own header and pixel layout, not a PNG's. Converting the PNG into a genuine .ico file is what makes it usable in that context.

Choosing a source image for icon conversion

A source PNG with a simple, high-contrast design and, ideally, a transparent background tends to convert into the clearest icon, since icons are often displayed quite small where fine detail gets lost. A square image also avoids any unexpected stretching, since icon display contexts generally assume a square aspect ratio.

How to convert PNG to ICO

1Upload one or more PNG images.
2The output format is already set to ICO — no picker needed.
3Click convert.
4Download your .ico file, or all of them together as a ZIP.

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