Are my PNG files uploaded anywhere?

No. This conversion runs entirely inside your browser, so the file never leaves your device. You can confirm it yourself: open the network tab of your browser's developer tools and watch that nothing is sent while the file converts.

What size should the PNG be?

Square, and at least 256 pixels. Anything larger is scaled down to 256, which is the largest an ICO can hold. A non-square image is not cropped, so make it square before converting.

Does transparency survive?

Yes. The icon carries a PNG internally with its alpha channel intact, so a rounded or cut-out mark keeps its transparent corners.

Do I still need a favicon.ico in 2026?

For `/favicon.ico` at the site root, yes — browsers still request that path whatever else you declare, and some tools expect nothing else. Modern favicon links can point at a PNG or SVG alongside it, and most sites ship both.

Can I use this for a Windows application icon?

Yes, for a simple mark. ICO is the format Windows uses for executables and shortcuts, and a single 256-pixel image covers most of what the shell needs. Applications that must look sharp at 16 pixels in a crowded taskbar want a hand-drawn small size in a proper icon editor.

PNGtoICO

Convert PNG to ICO

Up to 3 files at once, 100 with Pro. Mixed formats are fine.

Converting PNG to ICO wraps your image in the icon container browsers and Windows still ask for, with its transparency intact, at up to 256 pixels. Start from a square image, drop it above, and put the result at the root of your site as favicon.ico — the conversion runs in your browser.

Why you still need a favicon.ico

Almost everyone converting a PNG to an ICO is making a favicon. Browsers have requested `/favicon.ico` from the root of every site for nearly thirty years and they still do, regardless of what your HTML declares — so having one there stops a stream of 404s in your logs and covers the tools that look for nothing else.

Modern favicon markup can point at a PNG or an SVG as well, and most sites ship both. The ICO is the fallback that never has to be declared.

What an ICO actually is

A container rather than a compression format, which is why this conversion loses nothing meaningful. Your image is stored inside it as a PNG, complete with its alpha channel, so a rounded logo or a mark with transparent corners keeps them exactly.

The 256-pixel ceiling, and the single-size limit

Two constraints come from the format. It caps at 256 pixels, so anything larger is scaled down — the size byte in an ICO header is a single byte, and 256 is written as zero because it does not fit.

And this produces one image rather than the several an ICO can hold. Windows and browsers scale it down as required, which is fine for a simple mark; a logo with fine detail genuinely looks better hand-tuned at 16 and 32 pixels, and that is a job for an icon editor rather than a converter.

Start from a square PNG

A non-square image is not cropped, so an oblong logo becomes an oblong icon sitting awkwardly in a browser tab. Square it up in whatever tool made it, at 256 pixels or more, and the result will sit correctly everywhere it is drawn.

How to make a favicon.ico from a PNG

Drop a square PNG onto this page, at least 256 pixels.
It is scaled if needed and wrapped as an ICO, in your browser.
Download it and put it at the root of your site as favicon.ico.

PNG vs ICO: an image against an icon container

PNG compared with ICO
	PNG	ICO
Full name	Portable Network Graphics	Windows Icon
File extension	.png	.ico
Media type	image/png	image/x-icon
Compression	Lossless — nothing is discarded	Lossless — nothing is discarded

Quality: Some quality is given up for a smaller file. At the default setting the difference is hard to see.
Where it runs: This conversion runs inside your browser. Your file is never uploaded, and it works with the network disconnected.
What can be lost: Scaled down to icon sizes; detail beyond 256 pixels is discarded.

PNG to ICO: sizes, transparency and favicons

Are my PNG files uploaded anywhere?: No. This conversion runs entirely inside your browser, so the file never leaves your device. You can confirm it yourself: open the network tab of your browser's developer tools and watch that nothing is sent while the file converts.
What size should the PNG be?: Square, and at least 256 pixels. Anything larger is scaled down to 256, which is the largest an ICO can hold. A non-square image is not cropped, so make it square before converting.
Does the ICO contain several sizes?: No — one image at up to 256 pixels. Windows and browsers scale it down as needed, which is fine for a simple mark. A logo with fine detail is better hand-tuned at 16 and 32 pixels in a dedicated icon editor.
Does transparency survive?: Yes. The icon carries a PNG internally with its alpha channel intact, so a rounded or cut-out mark keeps its transparent corners.
Do I still need a favicon.ico in 2026?: For `/favicon.ico` at the site root, yes — browsers still request that path whatever else you declare, and some tools expect nothing else. Modern favicon links can point at a PNG or SVG alongside it, and most sites ship both.
Can I use this for a Windows application icon?: Yes, for a simple mark. ICO is the format Windows uses for executables and shortcuts, and a single 256-pixel image covers most of what the shell needs. Applications that must look sharp at 16 pixels in a crowded taskbar want a hand-drawn small size in a proper icon editor.