PySimpleGUI 6.4 (released 11/02/2026)

python -m pip install --upgrade PySimpleGUI

6.4 rolls up everything that has been on GitHub since 6.3 (6.3.1 through 6.3.19).

New

• resizable can be a tuple to allow resizing in one direction only, e.g. resizable=(False, True) for vertical only
• Pane element - new sash_width and sash_cursor parameters
• Each PySimpleGUI program now gets its own taskbar identity on Windows, so the right icon shows when several are running
• Windows with a custom titlebar get a taskbar icon, including after minimize / restore
• popup_error_with_traceback shows the full traceback in a Multiline so the whole error can be copied
• set_options(tooltip_text_color=, tooltip_background_color=) to color tooltips application-wide
• set_options(set_tooltip_to_element_key=True) - debugging aid that shows each element's key as its tooltip
• set_options ignores options it doesn't recognize instead of crashing
• Window.frame_extents() and Window.current_frame_location()
• fname() debugging aid - print(f'[{fname()}] starting') prints the name of the function it's in
• Ctrl+C in a program using read_all_windows exits cleanly

Fixes

• Button.update(image_data=...) crashed on a button that didn't have an image
• Input.update with COLOR_SYSTEM_DEFAULT
• Mouse wheel stopped scrolling a scrollable Column when the pointer was over an element inside it
• auto_save_location crashed reading a location of [None, None] (#6904) and crept down by the titlebar height on Linux
• Window creation reworked for Linux and Wayland (#3507)
• disable_minimize=True crashed on Linux
• Right-click menus didn't close when clicking away on Linux (#6664)
• Windows: hiding or changing the menubar with Menu.update left a blank strip at the bottom of the window
• PyCharm "Edit" opened at the wrong line (file now comes before --line)
• Many color checks reworked so bad colors no longer crash element creation

Testing

• The 66 screenshot regression tests on Windows: 6.4 matches 6.3.19 everywhere. Against 6.3.0.1 the only difference is SNAP_03 - the Button.update(image_data=) crash that 6.3.4 fixed.
• Linux Mint: 65 of the 66 match the last Linux run (6.3.14). The one flagged, alpha_channel, is a see-through window - its contents are identical, only the desktop showing through it changed.

Every change since 6.3

The change log from PySimpleGUI.py, which is cleared at each release. Changes Claude made are marked "Claude:".

• 6.3.1 (3-Aug-2026) - Fixed a COLOR_SYSTEM_DEFAULT bug in Input.update
• 6.3.2 (3-Aug-2026) - Changed editor format string for PyCharm to "<editor> <file> --line <line>". The file should be before the line number parms
• 6.3.3 (8-Aug-2026) - Changed a LOT of checks for valid colors when setting tkinter widget colors.... more to go
  • (9-Aug-2026) More color check changes. Added _is_valid_color that calls tkinter to check the color string when checking colors
  • Removed _widget_set_fg_color and _widget_set_bg_color functions that used to check for valid colors
  • Changed popup_error_with_traceback to now show the full traceback in a Multiline in the error window
  • Changed keyword parameters foreground to fg and background to bg for tkinter config calls
  • Made a TON of changes, broke lots of things, reverted 1/2 a ton of changes.
  • Ran automated regressions on this release flush out problems in the Element creation parameters
• 6.3.4 (12-Aug-2026) - Fixed bug when applying images in an element's update method. Was crashing when looking for widget.image. Needed to check attr exists first
• 6.3.5 (14-Aug-2026) - New feature for window resizing. Added ability to set resizable parameter when creating the window to the normal True/False as well as taking a tuple that indicates the directions the window can be resized (e.g. resizable=(False, True) means only allow resizing in the Y direction.
• 6.3.6 (15-Aug-2026) - Changed _error_popup_with_code to add the text at the top of the error window into the Multiline so that a user can copy the entire error using the Multiline
• 6.3.7 (18-Aug-2026) - New debugging aid - "set tooltip to element's key" is enabled by calling set_options(set_tooltip_to_element_key=True)
• 6.3.8 (21-Aug-2026) - Added kwargs to set_options. Used to soak up options that are not recognized. This keeps bad options from crashing the program. It won't help the older versions of PySimpleGUI that don't recognize a new option, but it will help from this version of PySimpleGUI onward
  • Added tooltip_text_color and tooltip_background_color to set_options so that they can be set on an application-wide basis
• 6.3.9 (24-Aug-2026) - Added try around call to tkinter mainloop in read_all_windows. It looks specifically for a KeyboardInterrupt. If caught, it'll print a message and call sys.exit to exit the application
• 6.3.10 (26-Aug-2026) - Fix for bug 6904. Was crashing when reading a location of [None, None] from settings file. Fix was to convert to a tuple
• 6.3.11 (26-Aug-2026) - Fix for bug 3507 (hopefully)... It's a Linux specific problem... it's also a fix for Wayland (successor to X11). It's a somewhat fundamental change to how every window is created. Rather than using Alpha to hide a window while it's being created, this version withdraws the window and uses a call I didn't know about to get the size of the window before it's fully created. master.winfo_reqwidth() master.winfo_reqheight(). Alpha was needed before so the window dimensions could be gathered to determine where to locate the window so it is centered on the screen.
• 6.3.12 (27-Aug-2026) - Another bite of the fix-auto-save-location bug fix apple
• 6.3.13 (27-Aug-2026) - Fix for the fix made in 6.3.11 when creating windows. Needed to add back the alpha method of hiding the window when the window has no titlebar. The withdraw method of hiding the window causes the titlebar to appear so can't use it for no titlebar windows
• 6.3.14 (27-Aug-2026) - Changed windows that use custom titlebar to use withdraw to hide the window during creation. It's providing an icon on the taskbar that I've not been able to get using previous methods. Still need to change the minimize window code for custom titlebar. Needed to change custom_titlebar_restore in order to show an icon on the titlebar when the window has been restored after minimize. It's Windows specific so need to test all this on Linux & Mac
  • Added function fname() to use as a debugging aid. When printed, it prints the function name of the function the print is inside of. Usage: print(f'[{fname()}] starting...') prints [my_func] starting...
• 6.3.15 (28-Aug-2026) - Fix for bug in Linux and Mac when disable_minimize=True when creating window. On Linux was crashing. Not sure about Mac but have a new way to remove the minimize button
• 6.3.16 (30-Aug-2026) - Pane element enhancement. Added parameters: sash_width, sash_cursor to Pane element. These fill out the common parameters used with Panes
• 6.3.17 (5-Sept-2026) - Claude: Fix for auto_save_location creeping on Linux. It saved winfo_x/y, which on X11 is the CLIENT corner (Windows: frame corner), and restored it as a frame position, so every run moved the window down by the titlebar height. Tk's geometry() read-back is no better on Cinnamon/Muffin (drifts once the window has been moved, invisible resize borders get included). Now the decoration size is measured once, from where the client area landed versus the position requested, and client corner minus decorations is saved. current_location(), size, move() unchanged. Added Window.frame_extents() -> (left, top, right, bottom) and Window.current_frame_location() -> value that round-trips through location= / move(). save_window_screenshot_to_disk titlebar height was 0 on Linux; now uses frame_extents().
• 6.3.17 (28-Oct-2026) - Claude: Windows taskbar App ID is now derived from the main script's path (PySimpleGUI.App.<md5 of path>) instead of one hardcoded string shared by every PySimpleGUI program. Windows treated all PySimpleGUI apps as ONE application, so with several running the taskbar could show the wrong icon (e.g. the Tk feather) for some of them. Each app now has its own taskbar identity; two instances of the SAME script still combine. set_options(win_app_id=...) still overrides. Windows-only - no change on Linux/Mac.
• 6.3.17 (28-Oct-2026) - Claude: Fix for Windows leaving a menubar-height blank strip at the bottom of the window when Menu.update hides or changes the menubar. Since the 6.3.11 withdraw-method window creation, removing the menubar makes Windows grow the client area by the bar's height instead of shrinking the frame. Menu.update now measures the client size before changing the menubar and re-asserts it if the OS changed it.
• 6.3.18 (29-Oct-2026) - Claude: Fixed mouse wheel not scrolling a scrollable Column when the pointer is over child widgets. Moving onto a child fires a <Leave> on the canvas (NotifyInferior crossing) which unbound the wheel. unhookMouseWheel now keeps the bindings hooked when the pointer is still inside the scrolled frame or any of its descendants.
• 6.3.19 (30-Oct-2026) - mike & Claude: Fix for issue 6664. Call to self.TKRightClickMenu.grab_release in the _RightClickMenuCallback for Element and Window objects was causing the click away event to get discarded so that the close menu close doesn't happen. Only a problem on Linux.

Windows Test Results

🧪 PySimpleGUI 6.4 — Screenshot Regression Results

Fail threshold 0.1 % mean pixel difference · PNGs: baseline 65, new 66 · pairs compared 65 · _{compare_screenshots_gui.py v1.3 · 2026-11-02 15:08}

Test environment

🔸 = changed since the baseline run

Flagged screenshots (1)

Linux Test Results

🧪 PySimpleGUI 6.4 — Screenshot Regression Results

Fail threshold 0.1 % mean pixel difference · PNGs: baseline 66, new 66 · pairs compared 66 · _{compare_screenshots_gui.py v1.3 · 2026-11-02 13:25}

Test environment

🔸 = changed since the baseline run

Flagged screenshots (1)