1Upload the ICO icons you want to work on; the file opens on an editable canvas in your browser with nothing installed.
2Crop, rotate, resize, draw, add text and shapes, or adjust colour — every change lands on a working copy, never on your upload.
3Preview the result at full size before you commit to it.
4Export back to ICO, or to a lossless format instead if you are still part-way through editing.
ICO Editor FAQ
Does the file format limit what the editor can do?
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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. What the format can represent bounds what any editor can preserve, here or on the desktop.
Anything specific to ICO in the editor?
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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 knowing before you export over your only copy.
How does ICO Editor let me edit without installing anything?
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Concretely, the largest bitmap in the stack is the one you edit, and the smaller sizes are regenerated from your edited version at export rather than left showing the old artwork. The editing surface is the browser, so there is nothing to install and no licence to hold.
What can I actually change?
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Crop, rotate, flip, resize, draw, add text and shapes, and apply filters and colour adjustments. Everything is applied to a working copy, so the file you uploaded is never modified in place.
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.
What can I upload to ICO Editor?
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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 ICO Editor?
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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 ICO Editor 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.
Why would a modern-format site run ICO Editor?
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WEBP.to is built around the modern replacement for both of the old defaults: one format that does lossy, lossless, alpha and animation, and reliably lands smaller than the JPEG or PNG it came from. People arrive here having decided the old defaults are costing them bandwidth, and that decision immediately raises the rest: what size, what quality, what happens to the transparency. ICO Editor is on the same upload and the same account so those questions get answered in one place.
Once ICO Editor has run, what is worth doing next?
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The converter on this site moves images to and from WebP, PNG, JPG and AVIF, which is where you decide whether a smaller file is worth losing the older browsers. Doing it in that order matters: pick the pixels first and the container afterwards, because the container is the cheap decision and the pixels are the expensive one.
Do the sibling sites run something different?
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The engines are identical — same libraries, same workers, same caps. What is different is the opinion attached, and the opinion here rests on a property of the format this site is named after: the same .webp extension can hold a lossy VP8 frame, a lossless one, or an animation, so the sensible processing path is decided per file rather than per extension.
What happens to my file, and is an account required?
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No account, and nothing is retained: uploads are deleted from the workers shortly after the job finishes, and nothing is inspected, listed or indexed. Accounts exist for history and batch size only.