Why convert PNG to ICO
Windows shortcuts, desktop apps and website favicons use the ICO format, which bundles one picture at several sizes. Start from a square PNG logo for the best result.
PNG is PNG, the lossless format of screenshots, logos and graphics with transparency; ICO is ICO, the Windows icon format that also serves as a website favicon.
What changes
- Both formats are lossless here, so every pixel is kept.
- Transparency is kept.
- The icon contains the picture at 16, 24, 32, 48, 64, 128 and 256 pixels (up to the size of your image), each fitted into a transparent square.
- Photo metadata such as camera details and GPS location is not copied to the new file.
Nothing is uploaded
Your pictures are converted by your own browser and saved straight back to your device. There is no sign-up, watermark or daily limit, and you can convert up to five files at once.
How this works
The picture is decoded by your browser in a Web Worker, with phone orientation applied, then drawn at each icon size, saved as PNG and packed into an ICO file. Up to five files are converted one after another, and several results can be downloaded together as a ZIP. Nothing is uploaded, so there's no account or daily limit.
Frequently asked
Will the picture lose quality?
No: ICO is lossless, so every pixel is kept.
Are my images uploaded?
No. The conversion runs in your browser on this device; nothing is sent to a server.
Can I convert several files at once?
Yes, up to five at a time. Several results can be downloaded one by one or together as a ZIP.
Can I use the ICO as a favicon?
Yes. Name it favicon.ico and place it at the root of your site; browsers pick the size they need from it.
Sources
- W3C — Portable Network Graphics (PNG) Specification (Third Edition)
- Microsoft Learn — Icons (ICO file format: ICONDIR and ICONDIRENTRY)
- HTML Standard — OffscreenCanvas convertToBlob()
Reviewed Oct 19, 2026 · test vectors fixtures/convert/image/png-to-ico/