1Upload the ICO icons you want to work on; the file opens in an editable view in your browser with nothing installed.
2Make your changes — crop, rotate, resize, draw and recolour on an image; rewrite the words and restyle headings, lists and tables in a document — and every one of them 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 format that re-compresses nothing if you are still part-way through editing.
ICO Editor FAQ
Is my file uploaded, or does editing happen locally?
+
Editing happens in your browser; the file goes to our workers only for the operations that genuinely need server-side processing, and it is deleted shortly afterwards.
How does ICO Editor let me edit without installing anything?
+
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.
Anything specific to ICO in the editor?
+
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.
Is anything lost when I export?
+
Only what the export format cannot represent. Choose a lossless output while you are still iterating and a compressed one when you are finished — exporting to a lossy format between edit sessions is what accumulates damage.
What can I upload to ICO Editor?
+
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?
+
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.
Will ICO Editor lower the quality of my ICO icons?
+
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 ICO Editor on several ICO icons at once?
+
Yes. Icon files are tiny, so a batch of them completes almost instantly; the round trip is dominated by the upload, not the processing.
Why does a EPUB site host ICO Editor?
+
EPUB.to is built around the open eBook format — XHTML in a zip, reflowable by design, and readable on hardware nobody has thought about the layout for. A book is a zip full of markup, images and fonts, so almost every job people bring to an eBook site is really a job on one of those things. ICO Editor runs on the same upload and the same account as the conversions because that is where it is needed.
What should I do with the result once ICO Editor is finished?
+
The converter on this site moves books between EPUB, MOBI, AZW3, PDF and DOCX, so a title ends up on whatever hardware is actually going to read it. Doing that after ICO Editor means the conversion is made from the version you settled on, not from the one you were still fixing.
Is ICO Editor here the same tool the sibling sites run?
+
The engines are shared — the same toolchain, the same workers, the same limits. What a EPUB site adds is a view on reflow: which of these operations a reflowable book genuinely supports, and which ones only make sense on the fixed-layout media inside it. It also starts from one fact about the format this site is named after: the book is a zip of XHTML with a manifest, so the text costs almost nothing and every decision that matters is about the embedded images and font subsets.
Do I need an account, and does anything get kept?
+
No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, nothing is read and nothing is indexed. Free accounts exist for history and batch size, not for access.
