An .ico file holds several sizes of the same picture. Choose a PNG and the result card writes one with 16, 32 and 48 px inside, the sizes a browser tab and the Windows title bar and tray use, and shows the 48, 32 and 16 px versions on a dark and a light background before you download. For a Windows app icon, switch to the set that adds 24 and 256 px: Microsoft lists 16, 24, 32, 48 and 256 as the minimum for an app (checked 24 Oct 2026).

1. Click Choose a PNG, or drop the file on the page. Start from 256 × 256 or larger; transparent areas show as a checkerboard. Choose several PNGs at once and each becomes its own .ico, all in one zip.
2. Read the card: ICO and 16 · 32 · 48 are selected, and the dark and light previews show the icon at 48, 32 and 16 px. For the 512 × 512 sample the size line reads 26 KB → 5 KB · ICO · 16 · 32 · 48 px. Pick 16 · 24 · 32 · 48 · 256 for a Windows app; the sample then comes to 21 KB.
3. Click Download ICO. For a website, upload it to the site root as favicon.ico. For a Windows shortcut, right-click it, choose Properties, click Change Icon and browse to the file.

Which size does Windows show where?

At 100% display scaling, Windows uses 16 px for context menus, the title bar and the system tray, 24 px for the taskbar and 32 px for Start pins. It looks for an exact match first and otherwise scales the next larger size down (Microsoft Learn, Construct your Windows app's icon, checked 24 Oct 2026). With the default set the taskbar's 24 px comes from the 32; the second set has its own 24 and a 256 for large views.

Does a website still need favicon.ico?

It is the safe default: browsers request /favicon.ico from the root of a site on their own, and one .ico can hold several sizes (MDN, the link element, checked 24 Oct 2026). For the PNG icons phones use as well, click More options... in the card: it downloads one zip with favicon.ico (16, 32 and 48 px), 180, 192 and 512 px PNGs and a head.html with the link tags.

Why does the 16 px version look blurry?

At 16 px a thin line or a word turns into a few gray pixels, and the previews in the card show it before you download. Simplify the mark or thicken its lines in the editor behind the card; the previews and the size line update as you edit.

How big should my PNG be?

At least as big as the largest size you pick: 48 × 48 for the default set, 256 × 256 for the set with 256. A smaller picture is enlarged for that size and looks soft, and the card says so under the title.

What are the limits?

There are two size sets, not any combination. Each size is stored as a 32-bit PNG inside the .ico. A picture that isn't square is centered with clear edges rather than cropped. Up to 100 million pixels a file. The conversion runs in your browser; nothing is uploaded.

Updated 2026-10-24

More toolsJPG to ICOImage converterResize image

An .ico file holds several sizes of the same picture. Choose a PNG and the result card writes one with 16, 32 and 48 px inside, the sizes a browser tab and the Windows title bar and tray use, and shows the 48, 32 and 16 px versions on a dark and a light background before you download. For a Windows app icon, switch to the set that adds 24 and 256 px: Microsoft lists 16, 24, 32, 48 and 256 as the minimum for an app (checked 24 Oct 2026).

1. Click Choose a PNG, or drop the file on the page. Start from 256 × 256 or larger; transparent areas show as a checkerboard. Choose several PNGs at once and each becomes its own .ico, all in one zip.
2. Read the card: ICO and 16 · 32 · 48 are selected, and the dark and light previews show the icon at 48, 32 and 16 px. For the 512 × 512 sample the size line reads 26 KB → 5 KB · ICO · 16 · 32 · 48 px. Pick 16 · 24 · 32 · 48 · 256 for a Windows app; the sample then comes to 21 KB.
3. Click Download ICO. For a website, upload it to the site root as favicon.ico. For a Windows shortcut, right-click it, choose Properties, click Change Icon and browse to the file.

Which size does Windows show where?

At 100% display scaling, Windows uses 16 px for context menus, the title bar and the system tray, 24 px for the taskbar and 32 px for Start pins. It looks for an exact match first and otherwise scales the next larger size down (Microsoft Learn, Construct your Windows app's icon, checked 24 Oct 2026). With the default set the taskbar's 24 px comes from the 32; the second set has its own 24 and a 256 for large views.

Does a website still need favicon.ico?

It is the safe default: browsers request /favicon.ico from the root of a site on their own, and one .ico can hold several sizes (MDN, the link element, checked 24 Oct 2026). For the PNG icons phones use as well, click More options... in the card: it downloads one zip with favicon.ico (16, 32 and 48 px), 180, 192 and 512 px PNGs and a head.html with the link tags.

Why does the 16 px version look blurry?

At 16 px a thin line or a word turns into a few gray pixels, and the previews in the card show it before you download. Simplify the mark or thicken its lines in the editor behind the card; the previews and the size line update as you edit.

How big should my PNG be?

At least as big as the largest size you pick: 48 × 48 for the default set, 256 × 256 for the set with 256. A smaller picture is enlarged for that size and looks soft, and the card says so under the title.

What are the limits?

There are two size sets, not any combination. Each size is stored as a 32-bit PNG inside the .ico. A picture that isn't square is centered with clear edges rather than cropped. Up to 100 million pixels a file. The conversion runs in your browser; nothing is uploaded.

Updated 2026-10-24

More toolsJPG to ICOImage converterResize image