- Upload Images — Drop or browse PNG/JPG files (bulk supported).
- Select Sizes — Toggle icon sizes: 16×16, 24×24, 32×32, 48×48, 64×64, 128×128, 256×256.
- Generate — Click 'Generate ICO' to create multi-size ICO files.
- Download — Download individual .ico files.
ICO Converter — Generate Favicon ICO Files
The ICO Converter is a free tool that generates .ico (favicon) files from PNG or JPEG images entirely in your browser. It creates proper multi-size ICO files containing multiple resolutions in a single file — exactly what browsers and operating systems expect.
What is ICO Format?
ICO (Icon) is a file format developed by Microsoft for storing icons. Unlike regular image formats, a single .ico file can contain multiple images at different sizes and color depths. Web browsers use .ico files as favicons — the small icon displayed in browser tabs, bookmarks, and history.
Available Sizes
- 16×16 — Browser tabs, address bar (essential)
- 24×24 — Windows toolbar icons
- 32×32 — Windows taskbar, shortcut icons (essential)
- 48×48 — Windows desktop icons (recommended)
- 64×64 — High-DPI browser tabs
- 128×128 — macOS Dock, large icon views
- 256×256 — Windows Vista+ extra-large icons
Features
- Multi-Size ICO — Embed 1-7 sizes in a single .ico file.
- Bulk Convert — Process multiple images at once.
- Proper Binary — Generates valid ICO binary format.
- PNG Encoding — Uses PNG compression inside ICO for smaller files.
- 100% Private — No uploads, pure client-side.
Best Practices
- Start with a square image (1:1 aspect ratio)
- Use PNG with transparency for best results
- Include at least 16×16, 32×32, 48×48 for web use
- Test your favicon in multiple browsers after deployment
Privacy
All ICO generation happens in your browser. The tool constructs the binary ICO format using JavaScript. No files are uploaded.