JPG is the most widely used lossy format for photos. JPG opens in most environments, but another format such as ICO may suit some uses better.
ICO is a container format for favicons and Windows icons. When you convert JPG to ICO, you get a format that supports transparency and it can be used as an icon or favicon. See the comparison below for what changes.
This converter reads the file itself to confirm it is JPG, then converts it to ICO right in your browser. Your image is never uploaded.
JPG vs ICO: what's the difference?
| Item | JPG | ICO |
|---|---|---|
| Compression | Lossy | Lossless |
| Transparent background | No | Yes |
| Animation | No | No |
| Introduced | 1992 | 1985 |
| Support in programs and upload forms | nearly everywhere | moderate |
| Shown directly in browsers | Yes | Yes |
| Photo file size (JPG = 1) | baseline (1×) | n/a |
What is JPG?
JPG (JPEG) is a lossy format standardized in 1992. It drops information the human eye is less sensitive to, making photos very small. It is the format cameras and smartphones save by default, so it is the one you meet most often.
What is ICO?
ICO is the format used for Windows icons and website favicons. Its distinguishing feature is that one file can hold several sizes, such as 16×16, 32×32 and 256×256.
What changes when you convert JPG to ICO
Converting doesn't add a transparent background
JPG has no transparency information, so converting to ICO keeps the background as it is. To remove a background you need a separate background-removal tool.
Quality doesn't improve, but it doesn't get worse either
Information lost when JPG was saved can't be recovered. ICO is lossless, so it keeps the image exactly as it is now and later edits and saves add no further degradation. File size will grow, though.
It is fitted into a square of at most 256×256
ICO is limited to 256×256. Larger images are scaled down with their aspect ratio kept, and images that aren't square are centered with the leftover area left transparent.
ICO has no quality setting
ICO is lossless, so the quality slider doesn't apply. Instead, when converting from JPG you can manage file size by resizing (exact width and height, or a percentage).
How the file size changes
ICO holds images of up to 256×256, so a large original shrinks a lot. If the image is already small, the difference is negligible.
ICO has narrower support than JPG
JPG support is nearly everywhere and ICO support is moderate. Check that the recipient can open ICO first, and if you're not sure, JPG or PNG is safer.
When to convert
- You're making a website favicon or a Windows shortcut icon
- You're preparing an image for typical ICO uses (website favicons, windows program icons)
- You want to tidy a JPG file into a format that's easier to edit or archive
JPG → ICO: practical tips
A photo makes a hard-to-read favicon at small sizes. A square photo with a face or a simple subject large in the center is easiest to recognize.