1Upload the ICO icons you want resized — work from the largest original you have rather than from a copy you already shrank once.
2Type a target width, a target height or a percentage, and leave the aspect-ratio lock on unless you deliberately want stretching.
3Run the resize; every file in the batch is taken to the same target in a single pass.
4Download the resized ICO file, or the whole set together as one archive.
Resize ICO FAQ
How does Resize ICO change the dimensions?
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Concretely, the request is really about which sizes belong in the stack: entries are re-rendered at the standard 16, 32, 48, 64, 128 and 256 pixel steps rather than at an arbitrary dimension, because that is what Windows and browsers ask for. You give it a target width, a target height or a percentage, and it works from the original rather than from a previously resized copy.
Can I keep the aspect ratio, or force exact dimensions?
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Both. Lock the ratio and one dimension is derived from the other, which is what you want almost always. Unlock it and you get exactly the numbers you typed, at the cost of stretching — useful for a fixed slot, wrong for a photograph.
Does the source format affect the result of a resize?
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It does. ICO is a container that holds several square bitmaps at once (16, 32, 48, 64, 128 and 256 px) so Windows and browsers can pick the size they need. That is what decides whether shrinking the file is purely a question of pixels or also a question of re-encoding.
Is there anything specific to ICO I should watch for?
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Yes — an ICO is a stack of square bitmaps, not one image, so operations apply to the stack and Windows still picks whichever size it wants. Worth checking before you resize a file you will not be able to regenerate.
What is the most common mistake when resizing ICO icons?
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Upscaling. Enlarging cannot invent detail that was never captured, so the result is a soft version of the original at a bigger size. Always resize down from the largest source you have, and resize once rather than in stages.
What dimensions should I actually target?
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Match the slot it will live in. A full-width web hero rarely needs more than 1920 pixels wide, a content image 1200, a thumbnail 400, and doubling those numbers covers high-DPI screens. Anything beyond that is bytes nobody sees.
What can I upload to Resize ICO?
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ICO files containing one or several sizes, plus ordinary PNG or JPG artwork if you are building an icon rather than editing one. Windows .ico and browser favicon files are the same format.
Is there a file size limit on Resize ICO?
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Yes: free accounts process images up to 25 MB each, which no icon file will ever approach — a full 16-to-256-pixel stack is typically well under 200 KB. Icons are the one part of the image family where the cap is genuinely irrelevant.
Will Resize ICO lower the quality of my ICO icons?
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The sizes stored inside an ICO are lossless bitmaps, so the pixels themselves do not degrade. What actually decides how good an icon looks is whether the size the operating system asks for exists in the stack — a 256 px entry downscaled on the fly by Windows always looks worse than a real 32 px entry.
Can I run Resize ICO on several ICO icons at once?
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Yes. Icon files are tiny, so a batch of them completes almost instantly; the round trip is dominated by the upload, not the processing.
Which sizes should the icon contain?
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16, 32 and 48 pixels cover Windows Explorer and browser tabs; 256 covers large-icon view and modern shortcuts. Keeping all of them in one file costs almost nothing and stops the operating system from having to guess.
Does Resize ICO cost anything?
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No. Resize ICO is free with no account, and the output carries no watermark — which matters more here than anywhere else, since an icon is a handful of pixels with nowhere to hide one.
