What JPG to ICO does
ICO is the icon container Windows uses for program, folder and shortcut icons, and the format browsers have looked for at /favicon.ico since 1999. This tool takes a JPG or PNG, scales it to a 64 × 64 pixel square, and wraps it in a valid .ico file in your browser. It is the quickest way to get a favicon for a website or a custom icon for a Windows shortcut from an existing logo, with nothing uploaded.
What the ICO contains
Modern ICO files can store PNG-compressed images, which is what this tool writes: a 64 × 64 PNG inside the ICO header. Windows Vista and later, and every browser, read PNG-in-ICO. The result is small — usually under 10 KB — and keeps transparency if the source was a transparent PNG.
| Size | Where Windows / browsers use it |
|---|---|
| 16 × 16 | Browser tabs, address bar, Windows small icons |
| 32 × 32 | Windows taskbar, desktop at 100% scaling |
| 48 × 48 | Windows Explorer large icons |
| 64 × 64 | This tool's output — scales down cleanly to all of the above |
| 256 × 256 | Windows jumbo icons, high-DPI desktops |
A single 64 px image is adequate for favicons and ordinary shortcuts, since Windows and browsers downscale it. Professional Windows application icons should carry multiple sizes (16 to 256) drawn separately so small versions stay legible; for those, use a dedicated icon editor.
Preparing the source image
- Start square. Non-square images are scaled to fit the 64 px square, which can distort them. Crop to 1:1 first with the Image Cropper.
- Simplify. At 16 px, fine detail and thin text disappear. A bold symbol or one or two letters works; a full wordmark does not.
- High contrast. Tab icons sit on light and dark backgrounds; a mid-grey icon vanishes on both.
- Use PNG for transparency. A JPG source gives an opaque square; a PNG source with a transparent background gives a shaped icon.
- Test small. Zoom out to see how the icon reads at tab size before committing.
Favicons in 2026
Browsers accept PNG and SVG favicons via <link rel="icon">, and an SVG favicon scales perfectly and supports dark mode. The .ico file still matters as the fallback: browsers request /favicon.ico automatically when no link tag is present, older browsers and some tools (RSS readers, bookmark importers, Windows “pin to taskbar”) only understand ICO, and search engines use it in results. The usual setup is an SVG or PNG for modern browsers plus this ICO at the site root.
| File | Tag |
|---|---|
| /favicon.ico | None needed — auto-discovered; or <link rel="icon" href="/favicon.ico" sizes="any"> |
| /icon.svg | <link rel="icon" href="/icon.svg" type="image/svg+xml"> |
| /apple-touch-icon.png (180 px) | <link rel="apple-touch-icon" href="/apple-touch-icon.png"> |
Windows shortcuts and folders
Right-click a shortcut → Properties → Change Icon → Browse, and select the .ico. For folders, Properties → Customize → Change Icon. Windows caches icons aggressively; if a changed icon does not appear, sign out and back in or clear the icon cache.