How to use
- Turn bars-32x16.png into an ICO.
- Turn tile-48.png into an ICO.
- Expect 16, 32 and 48 pixel images in both.
Formula / how it works
bars-32x16.png and tile-48.png each become an ICO with three PNG images inside: 16, 32 and 48. The wide bars are letterboxed on white so they are not stretched into a square. The 48 pixel tile fits the largest slot more naturally and is still letterboxed if the aspect is not square. This is not the text favicon page. That page draws letters. This page takes a picture you already have. The ICO uses PNG payloads, which current Windows and browsers read. It does not write the ancient BMP-only ICO form. Smaller sizes are real images, not a single file scaled by the operating system at display time.
Letterboxing is the difference between this page and a stretch. The wide bars keep their shape and gain white beside them. The 48 pixel tile has less spare margin. Both ICOs still contain 16, 32 and 48. The text favicon tool is a different page because it draws glyphs rather than packing a picture.
Sixteen, thirty-two and forty-eight are packed for both the wide bars and the square tile. The wide bars are letterboxed so they stay wide. White sits beside them. The tile fills more of the square. Neither file is the text favicon, which draws letters instead of packing a picture. The payloads are PNG, which is what current systems expect inside an ICO. The ancient BMP-only icon is not what this button writes. Three sizes, every time, from the one picture you chose.
Count three images in the ICO, not one stretched master. 16, 32 and 48 are written for the bars and for the tile. White sits beside the wide bars. The text favicon page is not this one. PNG payloads, not the old BMP-only icon.
Open the ICO and count 16, 32 and 48 rather than trusting a single preview. The wide bars should still look wide, with white beside them, not stretched. The tile should fill more of the square. Letters belong on the text favicon page. This page packs a picture, using PNG payloads, three times, every run. The source image is not uploaded and not deleted.
After the download, the ICO should contain 16, 32 and 48, whether you started from the wide bars or the square tile. The bars stay wide, with white in the spare square. The tile fills more of that square. Neither result is a letterform from the text favicon page. The images inside are PNG. The old BMP-only icon is not produced. The picture you picked is still the original on disk. Count 16, 32 and 48 in the download before you replace a text favicon with this picture pack. Wide bars stay wide. The tile fills more of the square. White is the letterbox, not a mistake.
Pull the largest image back out with ICO to PNG.
Worked examples
ICO from the wide bars
Inputs: i2c-f: bars-32x16.png
On this page, take bars-32x16.png and press Make ICO. Expect 16, 32 and 48, letterboxed on white.
Result: ICO with 16, 32 and 48 pixel PNG images, letterboxed on white so the picture is not stretched. 0…
ICO from the 48 pixel tile
Inputs: i2c-f: tile-48.png
On this page, take tile-48.png and press Make ICO. Expect 16, 32 and 48, letterboxed on white.
Result: ICO with 16, 32 and 48 pixel PNG images, letterboxed on white so the picture is not stretched. 0…
Use cases
- Building a picture favicon from a logo.
- Letterboxing wide art instead of stretching it.
- Writing PNG images inside the ICO.
- Leaving the text favicon page for letters.
Tips & limitations
- White bars appear beside a wide image.
- A square tile fills more of the 48 slot.
- Three sizes are always written.
- BMP-only ICO is not the output.
FAQ
Which sizes are inside?
16, 32 and 48.
Are the bars stretched?
No. They are letterboxed on white.
Is this the text favicon tool?
No. That tool draws characters. This one takes a picture.
What image format is inside the ICO?
PNG.
Is the source uploaded?
No.
Can I request only 32?
No. The three sizes are the set.
Both sample ICOs contain 16, 32 and 48. A wide logo will show white beside the art.