ICO is a container format for favicons and Windows icons. Current browsers open ICO, but support in programs and services is uneven.
GIF is limited to 256 colors, and synonymous with short moving images. When you convert ICO to GIF, you can open it in more places. See the comparison below for what changes.
This converter reads the file itself to confirm it is ICO, then converts it to GIF right in your browser. Your image is never uploaded.
ICO vs GIF: what's the difference?
| Item | ICO | GIF |
|---|---|---|
| Compression | Lossless | Lossless |
| Transparent background | Yes | Yes |
| Animation | No | Yes |
| Introduced | 1985 | 1987 |
| Support in programs and upload forms | moderate | nearly everywhere |
| Shown directly in browsers | Yes | Yes |
| Photo file size (JPG = 1) | n/a | about 2.5× |
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 is GIF?
GIF is one of the oldest web image formats, created in 1987, and can use only up to 256 colors per image. The compression itself is lossless, but reducing the colors to 256 makes photos look visibly coarse.
What changes when you convert ICO to GIF
Semi-transparency is simplified to transparent or opaque
GIF doesn't support partial transparency. Soft fading edges and shadows can look jagged, like stair steps.
Colors are reduced to at most 256
GIF can use only 256 colors per image. Logos and pixel art stay nearly the same, but photos and gradients can show color banding.
An ICO with several sizes uses just one of them
An ICO can hold multiple sizes such as 16×16, 32×32 and 256×256. The result is one of those images. If you need a large image, use an ICO that contains the biggest size.
GIF has no quality setting
GIF is lossless, so the quality slider doesn't apply. Instead, when converting from ICO you can manage file size by resizing (exact width and height, or a percentage).
How the file size changes
ICO files are small icons, so the size difference after any conversion is only a few KB.
GIF opens in more places
Support for ICO in programs, document tools and upload forms is moderate, while GIF is nearly everywhere. If you need to upload somewhere ICO wouldn't open, try again after converting.
When to convert
- You need to upload to a program, messenger or upload form that can't open ICO
- You must upload a still image to an old board or system that only accepts GIF
- You want to pull a favicon or icon file out as an ordinary image for editing or documents