JPEG 2000 to ICO converter
Convert JPEG 2000 to ICO in seconds, free and unlimited. No upload, no sign-up, no watermark: your image never leaves your device.
Last updated
Quick answer: To convert JPEG 2000 to ICO, add the JPEG 2000 file to the iHateFiles JPEG 2000 to ICO converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. Turns artwork into a Windows icon or a favicon, written at every size a browser asks for.
Should you convert JPEG 2000 to ICO?
Do this when you are about to edit the file and want no further loss. Do not do it hoping to improve a JPEG 2000: ICO preserves what it is given, including the damage.
JPEG 2000 is lossy and ICO is not
Moving from JPEG 2000 to ICO stops any further loss, but it cannot undo what JPEG 2000 already discarded: that detail was thrown away when the file was first written and is not in it any more. Expect the ICO to be considerably larger while looking exactly the same, because it is now storing the JPEG 2000 artefacts faithfully too.
ICO supports transparency, but there is none to recover
ICO can store an alpha channel and JPEG 2000 cannot, so nothing is gained here automatically. The result is fully opaque. Transparency has to be cut in an editor; no converter can work out which parts of a JPEG 2000 were meant to be see-through.
Expect a much larger file
ICO stores every pixel exactly, including the compression artefacts the JPEG 2000 already has. The file will grow, sometimes by a factor of ten, without looking any better. Do this when you need to edit without further loss, not to improve the image.
JPEG 2000 and ICO side by side
| JPEG 2000 | ICO | |
|---|---|---|
| Compression | Lossy | Lossless |
| Transparency | No | Yes |
| Animation | No | No |
| Written here | No | Yes |
What usually goes wrong
About the JPEG 2000. It is technically better than JPEG and lost anyway. Support, not quality, decided it.
About the ICO. Renaming a PNG to favicon.ico works in most browsers and then fails in the one that matters. A real ICO bundle avoids the argument entirely.
How to convert JPEG 2000 to ICO
- Add your JPEG 2000 file. It is read from your disk and stays there.
- Check the settings. The output format is already set to ICO.
- Press convert and the ICO file is saved back to your device.
Questions
How do I convert JPEG 2000 to ICO?
Open this page, add your JPEG 2000 file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this JPEG 2000 to ICO converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to ICO lose quality?
ICO is lossless, so this step throws nothing away. If the original was already a lossy format, the damage it did cannot be undone, but nothing further is lost.
Can I convert several JPEG 2000 files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.