ICO to PNG Converter
- The Exif data, the colour profile and anything else the original carried are not passed on: the picture is decoded to plain pixels and a new file is written from them.
Needs JavaScript. Runs only here.
This page reads an ICO and writes out every picture it holds, on your own machine. Every conversion on this page runs in your browser. The picture is read, drawn and written on your own machine, and the file is not sent to a server.
Going the other way? Convert PNG back to ICO →
How do you convert an ICO to a PNG?
An ICO usually holds several pictures at different sizes. This page reads the directory, takes out every entry and writes each one as its own PNG.
An ICO file usually holds several images at different sizes. Converting to PNG pulls each one out as its own file with transparency intact; nothing is re-compressed, because both formats store their pixels without loss.
- Choose the ICO file you want to convert. It is read inside this page, on your own machine.
- Select Convert to PNG. The page reads the first bytes of what came back and refuses the file if they are not PNG.
- Download the pictures. The icon holds several, so you get one PNG for each of them.
What Changes From ICO to PNG
ICO to PNG reads the images the icon file contains and writes each one out as its own PNG, transparency intact. Nothing is compressed again, because both formats store their pixels without loss.
Each row below is one property of the picture: what it is in the ICO, what it becomes in the PNG, and whether it survives the trip. Convert a file and the same rows fill in with the measurements from your own picture.
| Property | In the ICO | In the PNG | Verdict |
|---|---|---|---|
| Dimensions | several images, each at its own size | each image keeps the size it had | kept |
| Colour model and bit depth | 32-bit ARGB, one PNG per entry | RGB with alpha, 8 bits per channel — 8 bits per sample, whatever the source held | changed |
| Alpha channel | present | carried through unchanged | kept |
| Colours used | up to 16,777,216 | the same pixels | kept |
| Animation frames | none — the several images are sizes, not frames | 1 each | kept |
| Metadata (Exif, ICC) | present in the file | dropped — a new file is written from pixels | lost |
| Compression | per entry — an uncompressed bitmap, or a complete PNG | lossless, deflate | changed |
| File size | the file you chose | one file per image the icon held | changed |
every image in the icon comes out as its own file; the Exif data does not.
Going Back to ICO
Converting back does not restore what this step dropped, so convert the PNG result back to ICO only when you need a ICO file.
The change above runs one way — go back from PNG to ICO writes a new file, not the original.
What Travels With the Picture
What the two formats are, and what the browser does with a picture on the way between them. None of this depends on which ICO you bring.
How ICO and PNG Are Defined
| Property | ICO | PNG |
|---|---|---|
| Compression | depends on the entry - each image inside is either an uncompressed device-independent bitmap or, from Windows Vista, a complete PNG | lossless - deflate with a sliding window of at most 32768 bytes (compression method 0) |
| Alpha channel | yes - a PNG entry must be 32-bit ARGB and its mask is taken from the alpha channel; a bitmap entry carries a separate AND mask | yes - a full alpha channel on colour types 4 and 6; a tRNS chunk gives a transparent colour key on types 0 and 2 and per-entry alpha on type 3 |
| Animation | none - the several images in an ICO are sizes of the same icon, not frames of an animation | yes - APNG is normative in the Third Edition, using the acTL, fcTL and fdAT chunks |
| In one sentence | An ICO file is a container. It holds several images at different sizes and colour depths, and software takes the one that suits the space it has to fill. | PNG stores a picture without losing anything: the specification defines lossless as reconstructing the original data exactly, bit for bit. It carries an alpha channel, and since the Third Edition it can carry frame-based animation as well. |
- A ICO file begins 00 00 01 00 - a reserved word that must be zero, then the resource type, which is 1 for an icon.
- A PNG file begins 89 50 4E 47 0D 0A 1A 0A.
- ICO is defined by no international standard; Microsoft documents the ICONDIR and ICONDIRENTRY structures.
- PNG is defined by PNG Specification (Third Edition), W3C Recommendation 24 June 2025; the Second Edition is ISO/IEC 15948:2004. The Third Edition is not itself an International Standard..
JPEG and lossy WebP save space by discarding picture detail, and what they discard does not come back. PNG, BMP and lossless WebP keep every pixel they are given, and GIF keeps every pixel it is left with after the palette has been applied.
PNG, GIF, WebP and ICO can carry transparency; JPEG cannot, because the standard defines no alpha channel, and a bitmap written here is opaque. Converting to a format without transparency fills the clear areas with a background colour.
PNG allows bit depths of 1, 2, 4, 8 and 16, and five colour types: greyscale, truecolour, indexed-colour, and each of greyscale and truecolour with alpha. Not every depth is legal for every type.
One ICO file holds several images at different sizes and colour depths, and software picks the entry that suits the space it has. Common practice for a website icon is 16, 32 and 48 pixels, but no specification requires a particular set.
Converting a picture back to the format it came from does not return the original file. Whatever a step discarded stays discarded, and the return trip writes a third file.
The browser decodes the picture to plain pixels and writes a new file from them, so the Exif data, the colour profile and anything else the original carried are not passed on.
A browser will display an ICO file, but it hands over one image, not the set the file contains. Reading every size means parsing the icon directory in JavaScript and decoding each entry, including the ones stored as a bitmap rather than a PNG.
Which Image Inside the ICO Do You Want?
Usually all of them
An ICO file is a container. It holds several images at different sizes and colour depths, and software takes the one that suits the space it has to fill. This page hands you every one rather than choosing for you, because which entry you want depends on what you are doing with it.
The largest, for editing
Take the biggest entry if you intend to redraw or repaint the picture. It carries the most detail, and anything smaller was made by shrinking something like it.
The exact one, for replacing
Take the entry at the size the software asks for if you are matching an existing icon. Scaling a picture to a size somebody already drew by hand is how a crisp icon turns soft.
Common Mistakes
- Expecting one file back. A container with four entries gives you four PNGs.
- Opening the ICO in a browser and saving the picture. That gives one entry, not the set.
- Scaling a small entry up. The larger entry is already in the file; take that one instead.
Frequently Asked Questions
Can you convert ICO to PNG?
Yes, and here you get every picture the file holds rather than one of them. Each entry is written out as its own PNG, with its transparency intact.
What is the difference between PNG and ICO?
An ICO file is a container. It holds several images at different sizes and colour depths, and software takes the one that suits the space it has to fill.
What program can open ICO files?
Windows opens one natively, and every browser will display one. Reading out each size separately is the part most software will not do, which is what this page is for.
Why does one ICO file produce several PNG files?
Because the container holds several pictures, one per size, and each is a separate picture rather than a scaled copy made on demand. One goes out per entry.
Does the PNG keep the icon's transparent background?
Yes. An ICO entry carries transparency either in its alpha channel or in a separate mask, and both are written into the PNG as a full alpha channel.
You can, but the round trip is not the file you started from: the PNG to ICO direction.
Related Conversions
The rest of the family sits on the full image format grid.