PNG to ICO
PNG to ICO turns one picture into a Windows icon file holding several sizes at once, so every tab, taskbar and desktop gets a sharp version. The file is a real multi-size .ico — 16, 32, 48 and 256 pixels in one document — rather than one scaled bitmap, and it is built in your browser; nothing is uploaded.
Drop a square PNG, or click to choose
or drop anywhere on this page · Choose a file · 100 MB
Accepted: PNG, JPG, JPEG, WebP, AVIF, HEIC
How does PNG to ICO work?
An .ico is not an image format. It is a directory: a header, one 16-byte entry per image, and then the images themselves. The operating system reads the directory and picks the entry that matches the size it needs — 16 pixels for a browser tab, 24 (or 32 on scaled displays) for the taskbar, 48 for Explorer’s medium view, 256 for extra-large icons on a high-DPI desktop.
Why one size is the wrong answer
Almost every “convert to ICO” tool produces a single 32×32 or 256×256 image. A single 32-pixel icon shown at 256 is a 32-pixel drawing enlarged eight times, which is exactly the blurry favicon everybody notices and nobody can place. A single 256-pixel icon shown at 16 is worse: the browser downsamples it with whatever filter it has, and fine strokes disappear into grey.
Each entry here is drawn from your original pixels at its own output size rather than resampled from a larger reduction. That matters at 16 pixels, where a one-pixel stroke is the difference between a legible mark and a smudge.
PNG entries, and the one place that is not enough
The format originally held device-independent bitmaps. Since Windows Vista an entry may instead be a complete PNG file, which is what this writes — smaller, keeps transparency, and needs no bitmap encoder. Windows 10 and 11, every browser and macOS’s own tooling read it.
The exception is worth stating: a very old Windows shell or a legacy installer may expect a bitmap entry for the small sizes. If your icon is going into something built before Vista, that is a real limitation rather than a theoretical one.
What makes a good source image
Square, at least 256×256, and transparent rather than white-backed if it will sit on a coloured tab strip. A mark with a solid silhouette reads at 16 pixels; thin strokes, gradients and small text do not, and no amount of resolution fixes that — which is why the 16-pixel preview above is the one to look at first.
Source
logo.png — 1024×1024, transparent
favicon.ico
16×16 PNG entry 1.1 KB
32×32 PNG entry 2.4 KB
48×48 PNG entry 4.0 KB
256×256 PNG entry 18.2 KB
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25.7 KB in one fileWhat options and edge cases does PNG to ICO support?
| Parameter | Type | Default | Behaviour & edge cases |
|---|---|---|---|
| 16 × 16 | size | on | Browser tabs and the bookmarks bar. The hardest size to get right and the one seen most often, so check this preview before any other. |
| 24 × 24 | size | off | Windows taskbar at 100% scaling. Off by default because the 32-pixel entry covers most of the same ground and every entry costs file size. |
| 32 × 32 | size | on | Small desktop icons and the taskbar on displays at 125% scaling. The size most single-size converters produce, and the reason a one-size icon looks acceptable until it does not. |
| 48 × 48 | size | on | Windows Explorer's medium icon view, and the size the desktop shortcut uses on a standard display. |
| 64 × 64 | size | off | macOS Finder's icon view and some Linux docks. Windows' large-icon view draws 96 pixels, which no ICO size row here covers. |
| 128 × 128 | size | off | The macOS Dock at its largest setting, and 2× renders of 64-pixel dock icons. |
| 256 × 256 | size | on | Windows extra-large icons and the thumbnail an installer shows. The format stores this as a PNG entry by convention, which is what it gets here. |
| Entry format | PNG | always | PNG-in-ICO, supported since Windows Vista and read by every browser and by macOS. A pre-Vista shell may expect a bitmap entry for the small sizes instead. |
| Transparency | preserved | yes | The alpha channel survives every size, so the icon sits on a coloured tab strip without a white box behind it. |
| Source ceiling | bytes | 100 MB | Everything runs in the tab, so a larger file is declined rather than attempted. A square source of 256 pixels or more is all the tool needs. |
Frequently asked questions
Why does my favicon look blurry in the browser tab?
Because the file has one size in it and the tab wants 16 pixels. A single 32-pixel icon shown at 16 is downsampled by the browser and loses its detail; a single 256-pixel icon is worse, because the browser's downscale drops thin strokes entirely. A multi-size .ico lets the browser pick the entry drawn at the size it actually needs, which is the whole point of the format.
Which sizes should I include?
16, 32, 48 and 256 covers everything in practice and is what this tool selects by default. Adding 24, 64 and 128 helps on specific scaling factors and costs a few kilobytes each. The 256-pixel entry is the one to keep even if you are tempted to drop it: Windows uses it for extra-large icons and installers, and its absence is why some shortcuts show a generic icon.
Does the .ico work in browsers, or only in Windows?
Both. Every browser reads .ico for the favicon, and the PNG entries inside are what they render. macOS reads it too — `sips` and Finder both handle it. The only environment that has ever had trouble with PNG-in-ICO is a Windows shell older than Vista, which is why the reference table says so rather than claiming universal support.
Should I also ship a PNG favicon and a web manifest?
Yes, and for different reasons. A PNG favicon at 180×180 is what iOS uses when somebody adds the site to their home screen, and a web manifest with 192 and 512 pixel PNGs is what Android uses. The .ico covers desktop browsers and Windows; the others cover mobile. They are complements, not alternatives.
My source is not square. What happens?
It is centre-cropped to a square, because every entry in an ICO is square by definition — there is one width and one height field per entry and they are written as the same number. Crop it deliberately first with the image cropper if the interesting part is not in the middle.
Is my image uploaded?
No. The decoding, the resize and the icon assembly all happen in this tab — the Network panel shows nothing when you drop a file. That matters here more than it looks: the image people turn into a favicon is usually an unreleased logo.