A real ICO file, not a renamed PNG
Windows reads the icon format by its contents, so changing .png to .ico in the file name does not work. The converter writes a proper ICO container that Windows tools and website favicon links can open.
PNG to ICO Converter
Add a PNG and get an ICO back with the transparent areas kept. The icon holds one image, up to 256 px.
To convert png to ico, add the PNG, keep ICO as the output and download the icon. In our test a 512 × 512 px transparent png became an ico holding one 256 × 256 px image, and its transparent corners stayed transparent. It is a single image, not a set of 16, 32 and 48 px sizes.
Transfers use HTTPS, and files converted on the free tier are deleted after 24 hours, so the result is not a long-term archive. Quality depends on the source file, so open the ICO file once before you share it.
FromPNGLosslessTransparency
PNG (Portable Network Graphics)
A lossless raster format with a full alpha channel. It preserves every pixel it is given and supports transparency, which makes it the usual choice for logos, screenshots, and any image with sharp edges or text.
ToICOLosslessTransparency
ICO (Windows icon)
A Windows icon container used for app icons, desktop shortcuts and website favicons. One file holds a directory of one or more images, each stored as a bitmap or an embedded PNG. Width and height are one byte each, so the largest size is 256 by 256 pixels.
A 512 × 512 px transparent PNG and a 400 × 200 px one, converted on indox.org
- PNGsquare sample, 512 × 512 px
- 4.1 KB
- ICOfrom indox, one 256 × 256 px image
- 8.1 KB
- PNGwide sample, 400 × 200 px
- 1.6 KB
- ICOfrom indox, one 256 × 128 px image, about 84× larger
- 135 KB
Why use indox to convert PNG to ICO?
Transparent areas stay transparent
We checked the pixels. In our test all four corners of the result still had zero alpha, and the soft edges of the artwork kept their partial transparency, so the icon does not get a black or white box.
The size limit is stated before you start
The result is one image of at most 256 × 256 px. If you need 16, 32 and 48 px images inside one file, you can pick another tool before you upload.
What happens to your PNG
Stays
- Your original PNG, which is not touched
- The transparent background, with partial transparency on the edges
- The shape and colours of the artwork at icon size
- The aspect ratio, even for a non-square image
Changes
- Format: the picture is stored in an ICO container
- Size: a 512 px image was reduced to 256 px in our test
- Images: one size only, with no 16, 32 or 48 px images
- File size: 4.1 KB became 8.1 KB for a square PNG and 1.6 KB became 135 KB for a wide one
- Storage: the square sample used an embedded PNG and the wide one an uncompressed bitmap
How do I convert PNG to ICO online?
- 1
Add your PNG
Drop the file on the box or choose it from your device. Use a square image if you can, because a non-square PNG stays non-square and a square one gives the cleanest icon. Keep the original PNG as your master.
- 2
Confirm ICO, then start the conversion
Check that ICO is the output format on the converter and start the conversion. In our test it took 2.7 seconds for the square sample and 8.9 seconds for the wide one, from the click to Completed.
- 3
Download the ICO and check it
Save the icon and open it where you plan to use it, for example as a shortcut icon or in your site's favicon link. If you need other sizes, make them in an icon editor or a favicon generator.
What do I get from indox's PNG to ICO converter?
You hand over a PNG, usually a logo or a small piece of artwork, and take away an ICO with its transparency intact. The page says what the file contains, so you know before you convert whether one icon of up to 256 px is enough for the job.
- One ICO from the PNG you add, in a few clicks
- Nothing installed on Windows, Mac or a phone
- Transparent background checked on real pixels, not assumed
- Single-image output and the 256 px cap stated up front
What are the limits for PNG to ICO?
Size
The upload box shows the live size limit before you add a file. Signing in raises it; a paid plan does not change it.
Formats
PNG in, ICO out. Pick another output on the converter if you need a different format.
Privacy
Files are encrypted in transit over HTTPS and processed on indox infrastructure.
Deletion
Free-tier files are kept for 24 hours after the job finishes, then deleted automatically.
Limits worth knowing
- The ICO holds one image. We did not see a 16, 32 or 48 px size in the result, and the converter showed no option to add sizes. If a site or app needs several sizes in one .ico, build that file in an icon tool.
- The largest size is 256 × 256 px. A bigger PNG is reduced to fit, so start from a source that still looks clear at that size.
- A non-square PNG is not padded to a square. Our 400 × 200 px sample gave a 256 × 128 px icon. Some programs show such an icon stretched or cropped, so pad the PNG to a square in an editor before you convert.
- A wide or tall image can give a much larger file. Our 1.6 KB wide PNG became a 135 KB ICO, about 84 times larger, because that icon was stored as an uncompressed bitmap.
- There is no option on the page to choose sizes, a background colour or a fit. We tested the default result only. This page covers PNG input only; for a JPG or SVG source see the related converters.
When the result is not what you expected
| What you see | Why | What to do |
|---|---|---|
| The icon looks stretched or cropped | The PNG was not square and is not padded | Pad the PNG to a square in an image editor, then convert it again |
| Only a large size is available in the file | The ICO holds one image of up to 256 px | Make the small sizes in an icon editor or a favicon generator |
| The ICO is far bigger than the PNG | A wide image can be stored as an uncompressed bitmap | Use a square source, or link a PNG favicon where an ICO is not required |
| The icon looks soft at small sizes | The image is scaled down from a larger one | Redraw the artwork simply at small size, and use PNG to JPG only for photos without transparency |
| A black or white box shows behind the icon | The source PNG has an opaque background | Remove the background in your editor and save the PNG with transparency first |
What do the free and paid plans add?
Free
- All converters
- Daily credit refresh
- Email support
Basic
- Access to all features
- AI Extract
- Priority conversions
- Email support
Highest priority
Premium
- Everything in Basic
- Highest priority queue
- Priority support
Pay-As-You-Go
- No subscription
- Credits never expire
- Opt-in auto-refill
- Access to all features
Which conversions are close to PNG to ICO?
PNG vs ICO: what is the difference?
| Compared on | PNG | ICO |
|---|---|---|
| Images per file | One image | A directory of one or more images |
| Largest size | No fixed limit | 256 × 256 px per image |
| Transparency | Full alpha channel | Alpha kept in our test |
| Where it is expected | Web pages, apps, design tools | Windows icons, shortcuts and classic favicon.ico |
| Typical use | Logos, screenshots, artwork | Icons for programs, shortcuts and sites |
Who can use a PNG to ICO converter?
When to use it
- Turning a transparent PNG logo into a favicon.ico for a small website.
- Making a desktop shortcut icon from a picture on Windows.
- Creating a quick placeholder app icon for an Electron or Windows build.
- Checking how a logo looks as an icon before building the full multi-size set.
Where can I read more about converting files?
Sources
- ICO file format (Kaitai Struct format gallery)Kaitai Struct
- Icon Format (ICO) overviewMicrosoft Learn
Facts checked on November 4, 2026
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PNG to ICO FAQs
How do I convert PNG to ICO?
Open the converter, add your PNG, keep ICO as the output and download the result. You do not need Photoshop or any program on your computer.
Which sizes does the ICO contain?
One. In our test the ICO had a single image of 256 × 256 px, with no 16, 32 or 48 px images. The converter showed no option to add sizes.
Does the ICO keep the transparent background?
Yes in our test. All four corners of the result were fully transparent and the soft edges kept their partial transparency.
What happens if my PNG is not square?
It stays non-square. Our 400 × 200 px PNG gave a 256 × 128 px icon, not padded to a square. Pad the image to a square in an editor first if the icon will be shown in a square slot.
Can I just rename my .png file to .ico?
No. An ICO is its own container with a directory of images, and Windows and browsers check the contents. A renamed PNG is still a PNG, which is why you convert it.
Can I put several sizes in one ICO here?
No. This converter writes one image per ICO. Make the 16, 32 and 48 px images in an icon editor or a favicon generator and combine them there.
Can I use a PNG as a favicon directly?
Many sites link a PNG favicon, so an ICO is not always needed. You need the ICO form for the classic /favicon.ico file, Windows shortcuts and desktop app icons.
Is my file uploaded?
Yes. The conversion runs on indox servers, not in your browser. Only add files you are comfortable uploading, and check the converter page for the current retention terms.
How do I convert the ICO back to PNG?
Use an ICO to PNG converter. This page converts from PNG to ICO only.
Why is my ICO so much bigger than the PNG?
The icon format can store an image as an uncompressed bitmap. In our test the wide sample was stored that way and grew from 1.6 KB to 135 KB, while the square one was stored as an embedded PNG and stayed small.