What this tool does
Drop up to ten images and each one comes back as a 64-pixel .ico file, ready to use as a website favicon or a Windows shortcut icon. PNG, JPG, WebP, SVG, HEIC, TIFF, BMP, GIF and even PDF pages all work as the source; you do not have to prepare a square PNG first. Each icon downloads on its own, and a ZIP appears when you convert more than one.
Everything runs in your browser, so unreleased branding never leaves your machine — which is the usual reason people are uneasy about uploading a logo to a favicon site.
What ICO is, and why it still exists
ICO is a container rather than a compression format. One file holds several complete images at different pixel sizes, each stored as a bitmap or, since Windows Vista, as an embedded PNG. Whatever is drawing the icon picks the size that fits the space, which is how a 16-pixel browser tab and a 48-pixel desktop shortcut can come from one file without either looking like a bad resample.
It survives for two unglamorous reasons. Browsers still request /favicon.ico from the site root when no icon is declared in the HTML, so the file is fetched whether or not you provide one, and a missing one shows up as 404s in your logs. And Windows itself uses ICO for pinned sites and desktop shortcuts. Everything modern prefers PNG or SVG; ICO is the floor nobody has removed.
What you get here
| Detail | Value |
|---|---|
| Output size | 64 x 64 pixels, one image per file |
| Storage | PNG embedded in an ICO container — the modern form, read by Windows Vista onwards and every browser |
| Aspect ratio | Kept; a non-square source is centred with transparent space around it |
| Transparency | Preserved from PNG, WebP and SVG sources |
| Files per round | Up to 10 |
64 pixels is a deliberate middle: browsers downscale it cleanly for a 16 or 32 pixel tab, and Windows uses it directly at 48. If you need a single file holding true 16, 32 and 48 pixel versions rendered separately, that is a multi-size ICO and is worth building from a vector in dedicated software.
Designing a mark that survives 16 pixels
A favicon is usually displayed far smaller than it is stored. At 16 pixels there are 256 pixels in total, and most favicons fail because they are a full logo shrunk until it is unreadable rather than a mark designed for the size.
- One shape or one letter. Two elements merge into a smudge at tab size.
- High contrast against light and dark tab bars. A dark mark on a transparent background disappears in dark mode; give it a solid coloured backing.
- No thin strokes and no gradients. A one-pixel line either vanishes or turns grey through anti-aliasing.
- Start square. A wide logo gets transparent space added on the sides, so the artwork ends up smaller than the icon.
- Check it at actual size. Zoomed previews flatter an icon badly. Open a real tab.
Why the browser still shows the old icon
Favicons are cached unusually aggressively, in a store separate from the normal page cache, so a hard refresh often changes nothing. What does work: open the icon URL directly in a tab and refresh there, add a query string to the link tag when the artwork changes, or check in a private window. If it is correct in a private window and wrong in the normal one, it is caching rather than your markup. Search engines and link-preview services fetch icons on their own schedule, so a correct favicon can take days to appear beside your result.