Convert any PNG image to a proper multi-size ICO file. Perfect for favicons, Windows application icons, or any project that needs a .ico container. 100% private — conversion happens in your browser.
Updated: August 24, 2026 Built by Khalil Rahman 100% client-side
Drop or click to upload a PNG image
Best results: square image, 256×256 pixels or larger
Original Image
Pro tip: For favicons, include 16×16, 32×32, and 48×48 sizes. For Windows desktop icons, include all sizes up to 256×256 for the sharpest appearance at every zoom level and DPI setting.
100% Private & Secure: All image processing happens locally in your browser. Your PNG is never uploaded to any server.
How to Use This PNG to ICO Converter
Converting a PNG to ICO takes about ten seconds:
1
Upload Your PNG
Drag and drop the file onto the upload zone, or click it to browse. The tool works best with square images at least 256×256 pixels.
2
Choose Icon Sizes
Select which sizes to embed in the ICO file. A live preview grid shows your image at each size, so you can verify it looks sharp everywhere.
3
Download the ICO
Click the convert button and your multi-resolution ICO file downloads instantly. Rename it to favicon.ico and upload to your site root.
💡 Tip: A PNG with a transparent background works best. The converter preserves alpha transparency in every size of the ICO, so your favicon looks clean on both light and dark browser themes.
What Is an ICO File, and When Do You Need One?
An ICO file is a small container that holds multiple images of the same subject at different resolutions — typically 16×16, 32×32, 48×48, and up to 256×256 pixels. The operating system or browser then picks the ideal size for the context: a 16-pixel version for a browser tab, a 48-pixel version for a Windows taskbar, and a 256-pixel version for a high-DPI desktop shortcut.
You need an ICO file in these common scenarios:
Website favicons. Browsers still fall back to favicon.ico in the site root. A proper ICO works across every browser and OS.
Windows desktop shortcuts. Right-click any shortcut, choose Properties → Change Icon, and pick your .ico file. Windows uses it at multiple sizes automatically.
Windows applications. Executable files embed an ICO as their main icon. Developer tools like Visual Studio or resource editors use it directly.
Bookmarks and pinned tabs. Browsers show the favicon in bookmarks bars and pinned tabs, using the largest ICO size available.
PWA icons. Progressive Web Apps can reference ICO files, though PNG at various sizes is now preferred.
Common Mistakes to Avoid
Using a non-square image. ICO files store square icons. Non-square images are stretched or squeezed, distorting the design. Always crop to 1:1 aspect ratio first.
Starting too small. If your source PNG is 64×64 and you request a 256×256 ICO size, the converter has to upscale — producing a blurry result. Start at 256×256 or larger.
Fine detail at 16×16. Text, thin lines, and complex gradients vanish at 16×16 pixels. Simplify your design or use a distinct silhouette for small sizes.
Ignoring transparency. A white-background PNG will produce a white-box favicon on dark browser themes. Use a transparent PNG for best results.
Only including one size. A single-size ICO looks blurry on some devices. Always include at least 16, 32, and 48 — and ideally 256 for modern high-DPI screens.
Wrong file extension casing. Some servers are case-sensitive. Always name the file favicon.ico in lowercase for maximum compatibility.
Why We Built This Tool
Most online PNG-to-ICO converters upload your image to a remote server, run an algorithm on it, and send the result back. That means your logo, app icon, or brand asset leaves your device — even for a few seconds. For a designer working under NDA, that is unacceptable.
Ours runs entirely in your browser using the HTML5 Canvas API and JavaScript's FileReader. Your PNG never leaves your device. You can use the tool offline, in an airplane, or on an air-gapped network. If you spot a bug, or you'd like us to add a feature — like round-icon masking, JPG/SVG input, or a custom canvas size — drop us a note using the contact link below.
SkillsInsider Editorial
Reviewed and maintained
The ICO container format and canvas rendering logic in this tool were verified against the Microsoft ICO specification and tested across Chrome, Firefox, Safari, and Edge. If you spot an error, or you'd like a new feature, please
send us the details so we can fix it. Last reviewed: October 2026.
ICO files contain one or more small images at different resolutions. They are primarily used as favicons for websites and as application icons on Windows. A single ICO file can hold 16×16, 32×32, 48×48, 64×64, 128×128, and 256×256 pixel versions of the same image, so the operating system or browser can pick the ideal size for each context. This makes ICO perfect for favicons and desktop shortcuts where clarity at multiple zoom levels matters.
For a modern website favicon, include at least 16×16, 32×32, and 48×48 pixels. For a Windows desktop or application icon, include all sizes up to 256×256 — that includes 16, 32, 48, 64, 128, and 256. Including more sizes makes the icon sharp at every zoom level and DPI setting. Our converter packs as many sizes as you select into a single .ico file automatically.
Upload the generated ICO file to your website's root directory (usually as /favicon.ico), then add <link rel="icon" type="image/x-icon" href="/favicon.ico"> inside the <head> section of your HTML. Browsers will automatically request /favicon.ico even without this tag, but including it makes the intent explicit and helps search engines and RSS readers find it.
No. This converter runs entirely in your browser using the HTML5 Canvas API and JavaScript. Your PNG is loaded into memory locally, resized on-device, and packed into the ICO format without ever touching a server. You can even use this tool offline once the page has loaded, and no cookies or analytics track your images.
Detailed source images with fine text or thin lines lose clarity when shrunk to 16×16 pixels. For best results, start with a simple, high-contrast design — a bold shape, a distinctive letter, or a high-contrast logo. Our converter uses high-quality downscaling, but no algorithm can recover detail that simply does not exist at 16 pixels wide. Test your icon at each size in the live preview grid.
This tool accepts PNG files only. To convert a JPG, open it in any image editor and save as PNG first — this preserves transparency. For SVG, open it in a browser or vector editor, export as PNG at 256×256 or larger, then upload here. We may add direct JPG and SVG support in a future update.
There is no hard limit, but we recommend uploading PNGs between 256×256 and 1024×1024 pixels. Smaller than 256×256 means the 256-pixel ICO size will be upscaled and look soft; larger than 1024 wastes memory and slows conversion without improving the final icon. Square images work best — non-square images are scaled to fit and may distort.
Yes. The converter runs entirely in your browser using JavaScript, HTML5 Canvas, and the FileReader API — no server calls are made after the page loads. Once the page is cached, you can disconnect from the internet and still convert PNGs to ICOs. This makes it useful for air-gapped work, on planes, or in environments where you do not want to upload brand assets.
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