Build a genuine multi-resolution ICO from a transparent PNG, with favicon presets and contain, cover or stretch fitting.
Drag and drop one or more files, or choose files from your device.
Supported: .png · up to 10 sources · 20 MiB per source. Existing codec, duration, pixel and memory limits apply.
Existing standard sizes: 16, 24, 32, 48, 64, 128, 256. Every selected size remains embedded in one multi-resolution ICO.
Enter your values locally; no inputs are uploaded.
Check validation feedback before reviewing the browser-generated result.
Review the explanation, copy supported outputs or reset the workspace.
Choose one supported local file, review the conversion settings, select Convert and inspect the verified output before downloading. Yes. The output has a genuine ICO header and directory with one validated PNG-compressed image per selected size. It is not a PNG with a renamed extension. Modern icon readers support these PNG entries; legacy BMP-only icon readers may not.
Build a genuine multi-resolution ICO from a transparent PNG, with favicon presets and contain, cover or stretch fitting. ICO contains losslessly encoded PNG entries for modern icon readers. Square icon sizes necessarily resample non-square source images. Contain retains all content with transparent padding; cover crops and stretch changes proportions. Legacy pre-Vista BMP-only icon readers are unsupported.
Your file bytes, pixels, SVG content and filename remain in browser memory. They are not uploaded to a conversion server, saved by this tool or included in page analytics. Clipboard and downloads require explicit actions. Reset clears pending processing and owned preview URLs; ordinary page requests may still be logged.
Yes. The output has a genuine ICO header and directory with one validated PNG-compressed image per selected size. It is not a PNG with a renamed extension. Modern icon readers support these PNG entries; legacy BMP-only icon readers may not.
Choose any combination of 16, 24, 32, 48, 64, 128 and 256 pixels. The favicon preset selects 16, 32 and 48 pixels. A second preset selects all seven standard sizes.
It scales the complete source to fit inside each square icon and pads the unused space with transparency. A non-square source keeps its proportions. Cover instead crops overflow, while stretch deliberately changes proportions.
Yes. Each icon uses an RGBA PNG payload. Transparent padding and source alpha are supported, although browser resampling can alter edge pixels when fitting to a new size.
The converter checks the ICO directory count, dimensions, offsets, image sizes, planes and bit depth. Every embedded PNG is parsed and decoded, and its decoded dimensions must match the directory entry.
No. High-quality browser downsampling is used, but enlarging a small source cannot recover missing detail. Inspect the converted preview and provide a sufficiently detailed source for large icon sizes.
Build a genuine multi-resolution ICO from a transparent PNG, with favicon presets and contain, cover or stretch fitting.
ICO contains losslessly encoded PNG entries for modern icon readers. Square icon sizes necessarily resample non-square source images. Contain retains all content with transparent padding; cover crops and stretch changes proportions. Legacy pre-Vista BMP-only icon readers are unsupported.
Choose a supported source file. Keep the original dimensions when quality matters; apply optional resizing or fitting deliberately. Inspect original and converted previews, including transparent edges, small text and gradients. Review all warnings before downloading.
Yes. The output has a genuine ICO header and directory with one validated PNG-compressed image per selected size. It is not a PNG with a renamed extension. Modern icon readers support these PNG entries; legacy BMP-only icon readers may not.
Choose any combination of 16, 24, 32, 48, 64, 128 and 256 pixels. The favicon preset selects 16, 32 and 48 pixels. A second preset selects all seven standard sizes.
It scales the complete source to fit inside each square icon and pads the unused space with transparency. A non-square source keeps its proportions. Cover instead crops overflow, while stretch deliberately changes proportions.
Yes. Each icon uses an RGBA PNG payload. Transparent padding and source alpha are supported, although browser resampling can alter edge pixels when fitting to a new size.
The converter checks the ICO directory count, dimensions, offsets, image sizes, planes and bit depth. Every embedded PNG is parsed and decoded, and its decoded dimensions must match the directory entry.
No. High-quality browser downsampling is used, but enlarging a small source cannot recover missing detail. Inspect the converted preview and provide a sufficiently detailed source for large icon sizes.
Processing is browser-only with bounded input size, decoded pixels, output bytes and operation time. Files larger than 20 MiB, individual images above 16 MP or batches above 40 million frame/page pixels are rejected. SVG has a tighter 2 MiB source limit. These limits protect responsiveness; they do not imply universal codec support.