PNG to ICO Converter
Turn a PNG into an .ico file: the icon format Windows uses for programs and shortcuts, and the favicon.ico that websites keep in their root folder. One .ico holds several sizes of the same icon, and here you choose them: 16, 24, 32, 48, 64, 128 and 256 px. Transparent areas stay transparent in every size. Add one big PNG and every size is made from it, shrunk in halving steps so thin lines at 16 px stay crisp. Or add several PNGs, for example a hand-drawn 16 px version and a 512 px logo, and they go into one .ico: each size uses the picture that fits it best, and a picture that is exactly the right size is copied pixel for pixel. When the file is ready, the tool reads it back and lists what is inside, so you can see every size is there. Download the .ico, or a favicon pack with PNG sizes, an apple-touch icon and the HTML to paste. Nothing is uploaded and there is no sign-up.
100% private — everything runs in your browser. Everything runs in your browser; your files are never uploaded.
Your pictures
Inside your .ico (read back from the file)
| Size | Stored as | Bytes | Drawn from |
|---|
Sizes in the .ico
Runs in your browser with our own code: your pictures are never uploaded and nothing is saved. Transparency is kept in every size. You may use what you make here, including commercially, with no credit needed. The rights in your own pictures stay as they were.
How to convert a PNG to an ICO file
- Drop one PNG on the box, or several sizes of the same icon; or click Try a sample.
- Tick the sizes you want inside the .ico; 16, 32, 48 and 256 px are ticked to start.
- If your PNG is not square, choose fit, crop or stretch; add padding or a background colour if you like.
- Check the previews and the read-back table, then download the .ico or the favicon pack and copy the HTML.
What you can use it for
- Make favicon.ico for a website from a logo PNG
- Make a Windows program, shortcut or folder icon with every size it needs
- Combine a hand-drawn 16 px icon and a large logo into one .ico
- Keep the transparent background of a PNG icon
- Make a classic BMP .ico for older software that rejects PNG icons
- Check what sizes an .ico you made really holds
Which size is used where
| Size | Typical use | Tip |
|---|---|---|
| 16 px | Browser tabs, bookmarks, address bar | Simplify: thick shapes, little detail |
| 24 px | Small icon views | Optional |
| 32 px | Tabs on high-density screens, taskbar | Always include |
| 48 px | Windows shortcuts and folders | Include for Windows |
| 64 and 128 px | Large icon views | Optional; adds file size |
| 256 px | Extra-large desktop icons | Largest size an .ico can hold |
Inside the file, an .ico is a short directory followed by one image per size. Each directory entry records the width and height (a 0 there means 256), the colour depth, the length of the image and where it starts. The image itself is either a complete PNG or a bitmap whose stored height is doubled to make room for a 1-bit transparency mask.
How several PNGs are matched to sizes
| You add | 16 px comes from | 256 px comes from |
|---|---|---|
| One 512 px PNG | the 512 px PNG, shrunk in halving steps | the 512 px PNG, shrunk once |
| A 16 px PNG and a 512 px PNG | the 16 px PNG, pixel for pixel | the 512 px PNG |
| One 100 px PNG | the 100 px PNG, shrunk | the 100 px PNG, enlarged (the tool warns you) |
Shrinking a big picture to 16 px in one jump skips most of its pixels, so thin lines break up. Halving the size step by step averages every pixel on the way down, which keeps edges smooth. A picture that is already the right size is not touched at all.
PNG or BMP inside the .ico
| Stored as | Transparency | Read by | File size |
|---|---|---|---|
| PNG | Full alpha (soft edges) | Windows Vista and later, all current browsers | Small |
| BMP (32-bit + mask) | Alpha plus a 1-bit mask | Every Windows version and older tools | Larger |
Microsoft recommends PNG for 256 × 256 icons, so that size is always PNG here, even in BMP mode.
Favicons without the guesswork
- Use a square PNG of at least 256 × 256 px, with a transparent background.
- If your logo is a wordmark, use just the symbol or first letter for the favicon.
- Add 5 to 10% padding when the shape touches the edges, so it does not look cramped in a tab.
- Put favicon.ico in the site root and the link tags in every page head.
Starting from an SVG logo? SVG to ICO draws every size from the vector. Need a full set with a web manifest? Use the Favicon Generator. To look inside an .ico or get its sizes back as PNG, use ICO to PNG; for a Mac app icon, PNG to ICNS.
Sources
Sources: Wikipedia: ICO (file format); W3C PNG Specification (Third Edition); WHATWG HTML Living Standard: link rel=icon; PKWARE APPNOTE.TXT, the ZIP file format specification.
More free icon tools
Finishing your icons?
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See all free tools →Frequently asked questions
Is this PNG to ICO converter free?
Yes. There is no sign-up, no watermark and no limit on how many icons you make. The conversion runs in your browser, so your PNG never leaves your device.
Does the transparent background stay transparent?
Yes. Every size keeps the PNG’s transparency. With PNG storage each size is a full 32-bit PNG with its alpha channel; with BMP storage the small sizes are 32-bit bitmaps with a transparency mask. Tick Solid background only if you want a filled square.
Which sizes should my .ico contain?
16 and 32 px are what browsers show in tabs and bookmarks, 48 px suits Windows shortcuts, and 256 px is the largest size an .ico can hold, for big desktop icons. 16, 32, 48 and 256 are ticked to start; 16, 32 and 48 alone keep a favicon tiny.
Can I put several PNGs into one .ico?
Yes. Add them together, for example a 16 px icon you drew pixel by pixel and a large logo. Each size in the .ico uses the picture that fits it best: an exact-size picture is copied pixel for pixel, otherwise the smallest picture that is big enough is shrunk. The table under the previews says which picture each size came from.
What happens if my PNG is not square?
Icons are square. Fit keeps the whole picture and centres it with transparent space round it, Crop uses the middle square and cuts the sides, and Stretch squeezes it to a square. Fit is the default because nothing is lost.
Should I choose PNG or BMP inside the .ico?
PNG entries are smaller and are read by Windows Vista and later and by every current browser. BMP entries are the original icon format; choose them only if an old program refuses PNG icons. The 256 px size is always stored as PNG.
Why is my .ico bigger than my PNG?
An .ico holds a separate image for every size you tick, so it adds them up. Untick sizes you do not need, or use PNG storage, which is smaller than BMP.
Where do I put favicon.ico?
Put it in the root folder of your website, so it is at /favicon.ico, and paste the HTML from the tool into the head of your pages. The favicon pack names the file favicon.ico for you.
Is my PNG uploaded?
No. Reading the PNG, resizing it and writing the .ico and the ZIP all happen in your browser.