4.0 alpha (build 5034) is now available

The first alpha for 4.0 is now available! To download it, please head over to the forum:

Please note that this is an alpha! It is mostly complete but there are bugs, both known and unknown. DO NOT install this if you depend on Paint.NET for your livelihood, for instance, as it might crash at seemingly random times or even corrupt your data (that’s actually very unlikely but, still, use caution). After alpha comes beta, and then final (general availability) or "RTW" (release to web) (also sometimes called RTM).

NOTE: The alpha is not available via the updater in v3.5.11, even if you have “Also check for pre-release (beta) versions” enabled. The beta for 4.0, however, will be made available through that update channel (from v3.5.11, I mean). I’m deliberately doing this in order to keep the audience size smaller for now so that my inbox doesn’t get flooded (I’m also not advertising it on the website just yet). Newer 4.0 alpha builds will, of course, be automatically offered to you once you have any 4.0 alpha installed.

Here is a list of the most prominent changes between v3.5.11 and 4.0:

  • System requirements
    • Windows 7 SP1 or newer is now required.
    • Windows XP and Windows Vista are no longer supported ( will not install).
    • .NET Framework 4.5 is now required, and will be installed if needed.
    • A dual-core (or more!) CPU is highly recommended. (I no longer test on single core systems, btw.)
  • A brand new, asynchronous, fully multithreaded rendering engine
    • Performance scales very well with respect to the number of CPU cores, whether you have 2, 4, 6, or even 16 of them.
    • Performance scales much better with large, or even huge, images. Rendering will slow down and you will see tiles “trickling” in as they are completed, but the UI will still be responsive to your changes and clicks.
    • The canvas now uses hardware acceleration via Direct2D, which also improves performance.
    • Memory usage is lower.
  • Selections have been improved in many ways
    • Antialiased selections. You may turn this on/off at any time from the toolbar.
    • Selection outlines are now rendered with the “dancing ants” animation.
    • Performance of selection rendering and manipulation (Move Selection tool) have been fantastically improved.
  • General UI
    • The functionality previously provided by the Utilities, Window, and Help menus has been simplified, consolidated, and moved to the top-right corner of the main window.
    • A brand new Settings dialog makes it much easier to configure all the tool and toolbar defaults, among other things.
    • The zoom slider and units selector have been moved from the toolbar to the bottom right corner of the window (into the status bar).
    • The image thumbnail list is now left-aligned and does not move around when you switch between certain tools.
    • The image thumbnail list can now be reordered with drag-and-drop.
    • Updated theming to a white, blue, flat motif.
  • Tools
    • Tools may now draw directly with a blending mode, configurable from the toolbar. All of the layer blending modes are supported, as well as “Overwrite.”
    • Drawing tools (Pencil, Paintbrush, Eraser, Clone Stamp, Recolor) now have much smoother mouse input handling via GetMouseMovePointsEx.
    • Brush tools (Paintbrush, Eraser, Clone Stamp, Recolor) now have soft brushes support via a “Hardness” setting in the toolbar.
    • The Move tools (Move Selected Pixels, Move Selection) have a much better UI for scaling, moving, and (especially) rotation.
    • Color Picker has a configurable sampling radius, and can sample from either the current layer or the whole image.
    • Gradient tool now supports a new “Spiral” gradient type, and allows configuration of the repeat mode (none, repeat, wrapped).
    • Magic Wand and Paint Bucket now allow live adjustment of Tolerance and the Origin (click location) after clicking (press Enter to commit/finish).
    • Magic Wand and Paint Bucket can now sample from either the current layer or the whole image.
    • The Paint Bucket now supports anti-aliasing.
    • The Recolor tool can now use the color of the pixel where you click as the color to be replaced. Or, as usual, it can use the secondary color.
    • The new Shapes tool replaces the Line/Curve, Rectangle, Rounded Rectangle, Ellipse, and Freeform shape tools. 29 shapes are currently available. You may move, resize, and rotate a shape, as well as reconfigure any other properties from the toolbar (color, outline size, etc.) before committing it to the layer.
  • Miscellaneous
    • Layers can now be reordered with drag-and-drop
    • Edit –> Copy Merged
    • Shift+Backspace will now fill the selection with the secondary color (Backspace fills with primary color, as usual)
    • Ctrl+Click on the Move Layer Up/Down buttons will now move a layer to the top/bottom
    • New exception/error dialog
    • Improved battery life impact due to fixing the way the floating windows manage their transparency
    • now shows up in the “Default Programs” control panel so you can configure its file type associations
    • Improved performance of saving .PDN images
    • Image->Resize has improved super sampling quality