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ICO not working? Fixes for the most common problems

Most icon problems come down to three causes: missing sizes, a solid background, or a cache.

Updated October 2026

Find your symptom below and jump straight to the fix.

Each one says what causes it and what to do about it.

The icon looks blurry or pixelated

Cause: the .ico doesn't contain the size Windows needs, so it stretches or shrinks another one. A single 32 px image shown at 256 px will always look soft.

Fix: convert again from a PNG of at least 256×256 px. Our converter puts nine sizes in the file, from 16 to 256 px, so Windows never has to scale up.

If only the smallest sizes look muddy, the design has too much detail for 16 px. Thicker shapes and fewer elements help more than any setting.

There's a white or black box around the icon

Cause: the source image has a solid background. A JPG can't be transparent, and many PNG exports keep a white background.

Fix: remove the background in an image editor, save as PNG with transparency, and convert again. Transparency is kept in every size of the ICO.

Windows still shows the old icon

Cause: Windows caches icons by file path, so a rebuilt .exe or a changed folder icon can keep showing the previous picture.

Fixes, from quickest to most thorough:

  1. Rename the file or move it to another folder. A new path forces a fresh icon.
  2. Restart Windows Explorer: open Task Manager, find Windows Explorer, right-click it and choose Restart.
  3. Sign out and back in, or restart the PC.

The browser still shows the old favicon

Cause: browsers cache favicons separately from the page, often for a long time. A normal refresh doesn't replace it.

Fixes:

  • Open yourdomain.com/favicon.ico directly and reload that page.
  • Check in a private window, which starts without the cache.
  • Add a version to the link so browsers fetch it again:
<link rel="icon" href="/favicon.ico?v=2">

Google Search updates favicons on its own schedule, which can take days or weeks after a change.

"Invalid icon" or "Unable to set icon" errors

Cause: the file isn't really an ICO. Renaming logo.png to logo.ico changes the name, not the format. Build tools such as Electron Forge, Visual Studio and Inno Setup reject it.

Fix: convert the PNG properly. The tool-specific guides show where the file goes for Electron, PyInstaller, Visual Studio and Inno Setup.

The icon looks squashed or cropped

Cause: icons are square, and a wide or tall logo has to fit that square somehow.

Fix: our converter keeps the proportions and centres the image on a transparent square, so nothing is cut off. For the best result, crop or redesign the logo as a square first, for example using just the symbol without the company name.

Convert your PNG again, with every size

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