How to use
- Open sample.ico.
- Read the 48 pixel JPEG at quality 80.
- Read it again at quality 60. Smaller sizes stay in the ICO.
Formula / how it works
sample.ico stores PNG images at 16, 32 and 48. The page takes the 48 pixel image and writes a JPEG. Quality 80 and quality 60 are both 48 by 48 and about 0.8 KB on these bars. Smaller sizes stay inside the ICO and are not a second download. A transparent pixel would be painted white. BMP-only ICO files are refused, because the reader looks for a PNG signature and will not decode the old DIB form. If you need the 16 pixel image, build a new ICO whose largest image is 16. This page always returns the largest.
Forty-eight by forty-eight is the largest image in sample.ico, saved as JPEG at about 0.8 KB for both qualities on these bars. Sixteen and thirty-two stay in the icon. A DIB-only file is refused. There is no menu for the small size. Build another ICO if 16 must be the one you extract.
Forty-eight by forty-eight is the largest image in sample.ico, about 0.8 KB as JPEG at both qualities on these bars. Sixteen and thirty-two stay inside the icon. A DIB-only icon is refused. There is no menu that returns 16. Build another ICO if the small image must be the largest one. The source ICO is not uploaded.
sample.ico was built with 16, 32 and 48 pixel PNG images of the bars. The JPEG is the 48 pixel one, about 0.8 KB at both qualities. The smaller images are still in the ICO. They are not missing. They are just not this download. A BMP-only icon stops the page. If the art you need is 16 pixels, make an ICO where 16 is the largest image. This page will not add a size menu. The ICO is not uploaded.
The JPEG is 48 by 48 because that is the largest image in sample.ico, about 0.8 KB on these bars at both qualities. The 16 and 32 pixel images are still in the ICO. A DIB-only icon does not become a JPEG here. It stops. If you need the small image, it has to be the largest one in a different ICO. This page will not guess which size you meant.
Work in this order. Open the ICO and expect the largest image only. In sample.ico that is 48 by 48, about 0.8 KB as JPEG at both qualities on these bars. The 16 and 32 pixel images are still inside the ICO. They are not the file you just downloaded. A BMP-only icon stops, because this reader wants a PNG payload. If the design you need is the small one, it has to be the largest image in a different ICO. This page will not offer a dropdown of sizes. The ICO stays on disk.
A PNG of the largest image is ICO to PNG.
Worked examples
Largest icon at quality 80
Inputs: c2j-f: sample.ico | c2j-q: 80
On this page, take sample.ico, then 80 and press Extract JPG. Only the largest image is extracted.
Result: Largest ICO image: 48×48 JPEG. Smaller sizes in the same ICO are left out. BMP-only ICO files ar…
Largest icon at quality 60
Inputs: c2j-f: sample.ico | c2j-q: 60
On this page, take sample.ico, then 60 and press Extract JPG. Only the largest image is extracted.
Result: Largest ICO image: 48×48 JPEG. Smaller sizes in the same ICO are left out. BMP-only ICO files ar…
Use cases
- A JPEG of the largest icon image.
- Leaving 16 and 32 inside the ICO.
- Painting a transparent icon pixel white.
- Refusing a BMP-only ICO.
Tips & limitations
- Both runs were 48 by 48 and about 0.8 KB.
- Largest wins. There is no size menu.
- PNG signature required inside the ICO.
- Build a new ICO if you need 16 as the largest.
FAQ
Why 48 by 48?
sample.ico stores 16, 32 and 48, and 48 is the largest.
Where are the small images?
Still in the ICO. They are not the download.
What about a BMP-only ICO?
Refused.
Did quality 60 shrink the bars?
Not visibly. Both were about 0.8 KB.
Is the ICO uploaded?
No.
Can I ask for 16?
No. Make an ICO whose largest image is 16.
48 by 48 is sample.ico. Another icon returns whatever image is largest.