ICO to QOI Converter
Processing entirely on your device — large files may take a moment.
Windows Icon and Quite OK Image exist for different jobs: ICO is the Windows icon format. A single ICO file can bundle several sizes (16×16 up to 256×256) of the same icon, used for shortcuts, application icons and website favicons. QOI is popular with hobbyist engines and emulators; convert to PNG to view it anywhere.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How ICO compares to QOI
| ICO | QOI | |
|---|---|---|
| Compression | BMP members, PNG for large sizes | Lossless (RLE/delta) |
| Transparency | Supported (1-bit or alpha) | Supported |
| Animation | No (that is .cur/.ani) | Not supported |
| Metadata | None | None |
| Best for | Favicons and Windows app icons | Hobby engines, lossless simplicity |
How to convert ICO to QOI
- 1
Select your files
Drag & drop your ICO files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to QOI". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted QOI file individually, or grab everything at once as a ZIP archive.
About the ICO format
ICO is the Windows icon container, and one of the oldest formats still in daily use. A single ICO file bundles several renderings of the same icon — 16×16, 32×32, 48×48 up to 256×256 — so Windows can pick the right sharpness for shortcuts, Explorer views and taskbars. Each member is stored as classic BMP data or, for large sizes, PNG compression.
On the web, favicon.ico at the site root remains the one icon request every browser makes automatically, which keeps the format alive despite cleaner alternatives like PNG and SVG icons. Keep ICOs small: every visitor downloads one.
+ Strengths
- ✓Multiple sizes bundled in one file
- ✓Every browser falls back to /favicon.ico automatically
- ✓Deep Windows integration for app icons
! Limitations
- −Practical size ceiling around 256×256
- −Windows-centric; little use outside icons
- −Quality is frozen at export time
About the QOI format
QOI (Quite OK Image, 2021) is a lossless format defined in one short specification document: a stream of simple run-length and delta ops over linear pixels. An encoder fits in 300 lines, decodes faster than PNG, and compresses comparably for photographic content.
It has found a home in emulators, demoscene projects and hobby engines — anywhere people want images without a codec dependency. Viewers rarely support it, so converting QOI to PNG is the way to bring these files into normal tools.
+ Strengths
- ✓Radically simple spec (~200 lines)
- ✓Lossless with fast decode
- ✓No patent or licensing questions
! Limitations
- −Almost no viewer support
- −Larger than modern codecs for many images
Why convert ICO to QOI?
Converting makes sense where the strengths of QOI meet what ICO cannot give you. Radically simple spec (~200 lines) Meanwhile Practical size ceiling around 256×256 One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this ICO to QOI converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Will I lose quality converting ICO to QOI?
No — QOI is a lossless format, so every pixel of the converted image matches your original ICO file. You can also adjust the quality/size balance before converting when the target format supports compression.
What happens to EXIF data and other metadata?
Conversions here re-encode the image, and re-encoding generally does not carry the original metadata over. If the EXIF data of your ICO files matters (camera model, GPS, timestamps), keep the original file as the master and treat the converted copy as the shareable version.
Will transparent areas survive the conversion to QOI?
Transparency is kept whenever QOI actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.