PNG to ICO Converter
Convert PNG to ICO in your browser. PNG files usually come from screenshots, design exports, logos and web graphics; ICO is the better fit for favicons and Windows icons. You get a multi-size ICO with PNG-compressed icons (16, 32, 48 and 256 px by default). Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
PNG expected · other image formats also work
How to use PNG to ICO
- 1
Add your PNG files: drop them here, choose them, or paste from the clipboard.
- 2
Choose the icon sizes to include.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .ico files one at a time or together as a ZIP.
Why use Aback Images for png to ico
Where the ICO goes next
ICO opens in every browser (as a favicon), Windows and most Linux desktops.
ICO next to PNG
Both sides are lossless, so the size depends on how well the ICO encoder handles this picture compared with the PNG's lossless DEFLATE with a prediction filter chosen per row.
Written without a lossy pass
The ICO is written losslessly, so the pixels decoded from the PNG arrive unchanged, apart from precision beyond 8 bits per channel.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
PNG vs ICO
What changes from PNG to ICO
Encoding: the PNG uses lossless DEFLATE with a prediction filter chosen per row; ICO uses each size stored as a headerless BMP or as a complete PNG, and the download is a multi-size ICO with PNG-compressed icons (16, 32, 48 and 256 px by default).
Bit depth: 1, 2, 4, 8 or 16 bits per channel in the PNG; ICO allows 1 to 32 bits per pixel, set per size, and the ICO written here has 32 bits per pixel. 16-bit PNGs from photo and scientific software are reduced to 8 bits per channel.
Colour: RGB, greyscale, or an indexed palette of up to 256 colours in the PNG; ICO supports RGB or a palette, per image, written here as 8-bit sRGB.
Transparency: the PNG stores it as a full alpha channel, so edges and shadows can fade smoothly; the ICO keeps it as 8-bit alpha in 32-bit and PNG entries, or a 1-bit mask in old icons.
Metadata: the PNG can carry text chunks, an ICC profile, physical resolution and EXIF in an eXIf chunk; ICO can carry only a directory of the sizes inside, with no EXIF, but nothing is copied across.
About PNG
PNG stores pixels losslessly with full alpha transparency. It is ideal for screenshots, logos, UI and anything with sharp edges, but photos saved as PNG are several times larger than JPEG.
A PNG opens with an 8-byte signature and is a chain of chunks, each with its own CRC: IHDR (size, depth, colour type), optional PLTE and tRNS for palettes, one or more IDAT chunks with the compressed rows, and IEND.
PNG files usually come from screenshots, design exports, logos and web graphics.
About ICO
ICO is a container that bundles several sizes of the same icon (16, 32, 48, 256 px) into one file. It is still the most compatible format for website favicons and Windows app icons.
An ICO starts with a 6-byte ICONDIR (type 1 for icons) and a 16-byte entry per image giving width, height, colour count and offset. Each image is either a BMP without its file header plus an AND mask, or a complete PNG.
When converting PNG to ICO makes sense
ICO is the better choice for favicons and Windows icons, while PNG suits screenshots, logos, graphics and anything that needs transparency.
ICO strengths: Multiple sizes in one file; Required by Windows and supported by every browser as a favicon. Drawbacks to weigh: Max 256×256 per image; Not for photos.
Limitations
- Each size inside the ICO is scaled from your image, and detailed artwork loses legibility at 16 and 32 px, so simplify logos first.
- Non-square images are centred on a transparent square for each icon size.
More conversions
Related tools
Convert ICO to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. Batch, private, no uploads.
Convert PNG to JPG in your browser, with transparency filled in a colour you pick. Batch, private, no uploads.
Convert PNG to WebP in your browser, ready for images on websites and in apps. Batch, private, no uploads.
Convert PNG to AVIF in your browser, ready for maximum compression on modern websites. Batch, private, no uploads.
Convert PNG to PDF in your browser, one PDF page per image. Batch, private, no uploads.
Convert PNG to SVG in your browser, traced into real vector paths. Batch, private, no uploads.
Convert PNG to EPS in your browser, with transparency filled in a colour you pick. Batch, private, no uploads.
Convert any image (HEIC, PNG, WebP, AVIF, RAW, PSD, SVG and 26 more) to ICO in bulk, right in your browser.
Frequently asked questions
Does converting PNG to ICO lose quality?
ICO is written losslessly, so the pixels are stored exactly as decoded. 16-bit PNGs from photo and scientific software are reduced to 8 bits per channel.
Is transparency kept in the ICO?
Yes. PNG stores it as a full alpha channel, so edges and shadows can fade smoothly, and the ICO is written with an alpha channel, so transparent areas stay transparent.
Which icon sizes are included?
16, 32, 48 and 256 px by default, the set Windows and browsers expect. You can choose other sizes. Non-square images are centred on a transparent square.
Which apps open ICO files?
Every browser (as a favicon), Windows and most Linux desktops.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.