What is a .pdn file?
Paint.NET Image File · Design · Rick Brewster (dotPDN) · 2004
A .pdn file is a layered image from Paint.NET, the free Windows image editor that sits between Microsoft Paint and Photoshop. It keeps layers and transparency editable, and starts with the bytes PDN3.
What is a .pdn file used for?
Paint.NET began as a student project mentored by Microsoft and became a Windows staple for quick but capable editing. Its native format stores the layer stack losslessly: the file opens with the ASCII magic PDN3, an XML header, then the serialized layer data.
Nothing mainstream outside Paint.NET opens .pdn (a GIMP plugin and the pypdn Python reader exist). The everyday route is exporting: flatten to PNG or JPEG for sharing, or use the plugin ecosystem to save PSD.
What opens a .pdn file?
The .pdn format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Paint.NET
- GIMP (with plugin)
macOS
- No native option; convert to PNG/PSD first
Linux
- GIMP (with plugin)
- pypdn (Python)
Open a .pdn file step by step
- Confirm the file really is a .pdn. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Paint.NET or GIMP (with plugin).
- On Mac, use No native option; convert to PNG/PSD first.
- On Linux, try GIMP (with plugin) or pypdn (Python).
- Still stuck? Convert the .pdn to png, which opens more widely.
Why can't I open my .pdn file?
Almost always because no installed app understands Paint.NET. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .pdn at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .pdn file
You can convert a .pdn file to png, jpg, psd (via plugin), tiff using a conversion tool or the export menu of an app that opens it.
What is the .pdn file signature (magic bytes)?
A .pdn file starts with the hex bytes 50 44 4E 33, which read as PDN3 in ASCII. Programs identify Paint.NET by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for Paint.NET.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 50 44 4E 33 | 0 | PDN3 | ASCII PDN3 |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .pdn file?
A .pdn file is a layered image from Paint.NET, the free Windows image editor that sits between Microsoft Paint and Photoshop. It keeps layers and transparency editable, and starts with the bytes PDN3.
How do I open a .pdn file without Paint.NET?
Options are thin: a GIMP import plugin or the pypdn Python library. The reliable path is asking for a PNG or PSD export, or installing the free Paint.NET on Windows.
How do I convert .pdn to PNG or JPG?
Open the file in Paint.NET and use Save As with PNG (keeps transparency) or JPEG. Layers flatten automatically in those formats.
Does Photoshop open .pdn files?
No. Export from Paint.NET instead: with the PSD plugin installed you can save a layered PSD that Photoshop opens cleanly.
Related formats
Sources
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