How can I check whether my PNG-to-ICO file contains every size I selected?

Open the downloaded ICO with an inspector or decoder and compare its image entries with the sizes you selected. The file itself needs to contain each size.

A large preview cannot confirm that. It may display a scaled version of one frame.

If the preview looks fine, that doesn't tell me much. It's probably just one frame scaled up — I can't see what's missing from the file. The real check is opening the downloaded file and counting the images: how many are inside and what size each one is.

Check the saved file

Selected 16, 24, 32, 48, 64, 128, and 256 pixels? Your ICO should contain seven separate images with those dimensions.

SVGtopix’s published conversion test used three controlled PNG sources with all seven sizes selected. The downloaded files were decoded separately from the converter preview. Each contained seven embedded PNG frames:

• 16 × 16
• 24 × 24
• 32 × 32
• 48 × 48
• 64 × 64
• 128 × 128
• 256 × 256

These results describe the saved test files. They do not verify your own download.

What should you look for?

1. Download the official Greenfish Icon Editor Pro 4.5 portable package, extract it, and launch the program.
2. Pass the file path for your own ICO file as a startup parameter to open it. The Startup screen’s Open... option opens a New graphic dialog and does not open the file. Passing the file path as a parameter is the method that worked in this test.
3. Click List of pages on the toolbar. The list appears on the left side of the window.
4. The file should have one row for each size you selected. The test file in this article used seven sizes, so it had seven rows: 16 x 16, 24 x 24, 32 x 32, 48 x 48, 64 x 64, 128 x 128, and 256 x 256. Fewer or more rows, or a row with a size that does not match your selection, means the downloaded file does not match your selection.

When I downloaded the test ICOs, I opened them with Greenfish Icon Editor Pro 4.5 instead of trusting the preview. Each file had seven images — 16×16, 24×24, 32×32, 48×48, 64×64, 128×128, and 256×256. I was actually surprised the preview didn't show that. Counting them in the file list was the only way I could tell.

A square frame can contain rectangular artwork

Do not confuse frame dimensions with the area painted inside them.

In the published test, a wide PNG occupied 16 × 8 painted pixels inside a 16 × 16 frame. Transparent space filled the area above and below. The requested frame was present, and the artwork kept its proportions.

That distinction matters when an icon looks smaller than expected. Check whether the frame is missing or whether the artwork simply leaves transparent space.

Check before you use it

Create the ICO, save it, and inspect its entries before adding it to your app or website. If a selected size is missing, recreate the file and inspect the new download.

Before I use an icon, I check the image list inside the file first — not just the preview. I count the entries and make sure every size I picked is there. If one is missing, I regenerate the file and check the new download again.

Windows and other software can choose different frames for different display sizes. The published file checks do not establish which frame Windows Explorer, a browser, or every application will use. Installation and display behavior were not tested.

The PNG to ICO page includes the converter, downloadable test files, and decoded-frame records.