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
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.
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.
Is there a file size limit on Resize ICO?
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Yes: free accounts process images up to 5 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.
Why does a PNG site host Resize ICO?
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PNG.to is built around the format you use when you cannot afford to lose a pixel: lossless, alpha-capable, and the correct answer for screenshots, logos, line art and anything with hard edges. Image work is rarely one step: people arrive to change a format and leave needing the picture a different size, a different weight or a different shape. Running Resize ICO on the same upload pipeline, the same size caps and the same account is the whole reason it is here rather than on a fourth tab.
What should I do with the result once Resize ICO is finished?
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The converter on this site moves images to and from PNG, JPG, WebP, GIF and SVG — which is the step where the decision about transparency actually gets made. That is the step most people actually came for, and doing it after Resize ICO rather than before it means the conversion works from the file you finally settled on.
Is Resize ICO here the same tool the sibling sites run?
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The engines are shared — the same libraries, the same workers, the same limits. What differs is the advice, and the advice here starts from one fact about the format this site is named after: there is no quality slider to get wrong — a PNG round-trips bit-exactly, so the only thing edits cost you is file size. A PNG site is opinionated about where PNG is the right destination and where it is not, and that judgement is worth more than the button.
Do I need an account, and does anything get kept?
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No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, and nothing you process is indexed, listed or used for anything else. Free accounts exist for history and batch size, not for access.