Build Python desktop
apps visually

Buildfy is a drag-and-drop GUI builder that generates clean, runnable Python code for CustomTkinter — no boilerplate, no guessing the API.

Installation

Buildfy runs entirely in your browser — no installation required. Just open the app and start building. The only prerequisite is Python with CustomTkinter installed on your machine to run the exported code.

# Install CustomTkinter
pip install customtkinter

# Run your exported Buildfy app
python my_app.py

Quick start

Build your first app in under two minutes. This walkthrough creates a simple login form.

Toolbar

The toolbar spans the top of the Buildfy window and is divided into three zones: left (brand + menus), center (wordmark), and right (tools + zoom).

Menu system

All three menus (File, Edit, View) use a macOS-style frosted-glass dropdown. On Mac, shortcuts display as ⌘⇧⌥ symbols. On Windows/Linux they display as Ctrl/Shift/Alt text.

Widget panel

The left sidebar lists every available widget organized into collapsible categories. Use the search bar at the top to filter by name.

Canvas

The canvas is your app's visual editor. It shows a floating inner window (your future Python app) centered on a pannable grid background. Every widget placed here maps 1:1 to Python code.

Navigation

Selecting widgets

Snapping & guides

Right-click context menu

Properties panel

The right panel updates live whenever you select a widget. It is organized into three tabs: Layout, Style, and Behavior.

Property reference — CTkButton

Layers panel

The Layers section lists every widget on the canvas in z-order (topmost first). Use it to select, reorder, rename, show/hide, and lock widgets.

Basic widgets

The core display and interaction widgets. These map to fundamental CustomTkinter classes.

Input widgets

Interactive controls that accept user input. Each generates correct Python with proper post-placement calls for value initialization.

Container widgets

Containers hold other widgets. In the generated Python code, child widgets placed inside a container use the container as their master.

Display widgets

Node editor

The node editor lets you wire widget behaviors visually without writing Python event handlers. Open it via the Nodes button in the toolbar (⌘J / Ctrl+J) or by right-clicking any widget and choosing Edit Behavior (Nodes).

Node categories

Generated Python

When you export, the node graph produces a _setup_events method that is automatically called from __init__:

    def _setup_events(self):
        self.button_a1b2.configure(command=self._button_a1b2_click)

    def _button_a1b2_click(self):
        if value > 50:
            self.label_c3d4.configure(text="High!")
        else:
            self.entry_e5f6.place_forget()

Code panel

Toggle the live code panel with the Code button in the toolbar (⌘K / Ctrl+K). It opens as a resizable split pane alongside the canvas.

# Generated by Buildfy v3.0
import customtkinter as ctk
import tkinter as tk

ctk.set_appearance_mode("dark")

class App(ctk.CTk):
    def __init__(self):
        super().__init__()
        self.title("My App")
        self.geometry("800x600")
        self._setup_widgets()

    def _setup_widgets(self):
        self.button_a1b2 = ctk.CTkButton(
            self, width=120, height=36,
            text="My Button",
            fg_color="#F0525C"
        )
        self.button_a1b2.place(x=40, y=40)

Export & save

Save project (.bfy)

Projects save as .bfy JSON files. Press ⌘S / Ctrl+S or use File → Save. The format captures all widget state, positions, properties, and node graphs.

{
  "version": "3.0",
  "canvas": {
    "width": 800, "height": 600,
    "title": "My App", "theme": "dark"
  },
  "widgets": [
    {
      "id": "btn_a1b2c3", "type": "CTkButton",
      "name": "Button_a1b2",
      "x": 120, "y": 80, "width": 120, "height": 36,
      "properties": {
        "text": "Click Me",
        "fg_color": "#F0525C"
      },
      "locked": false, "visible": true, "zIndex": 0
    }
  ],
  "nodeGraphs": { "global": {} }
}

Export Python (.py)

Use File → Export Python or ⌘E / Ctrl+E. A modal shows a syntax-highlighted preview with a validation banner before you download.

# Generated by Buildfy v3.0
# Requirements: pip install customtkinter
import customtkinter as ctk
import tkinter as tk

ctk.set_appearance_mode("dark")
ctk.set_default_color_theme("blue")

class App(ctk.CTk):
    def __init__(self):
        super().__init__()
        self.title("My App")
        self.geometry("800x600")
        self.resizable(True, True)
        self._setup_widgets()

    def _setup_widgets(self):
        self.button_a1b2 = ctk.CTkButton(
            self, width=120, height=36,
            text="Click Me", fg_color="#F0525C",
            font=("Inter", 13)
        )
        self.button_a1b2.place(x=120, y=80)

def main():
    app = App()
    app.mainloop()

if __name__ == "__main__":
    main()

Export formats

Keyboard shortcuts

All shortcuts use ⌘ on macOS and Ctrl on Windows/Linux. Buildfy detects your OS automatically.

File

Edit

Canvas & view

.bfy file format

Buildfy projects are stored as .bfy files — standard JSON with a defined schema. You can inspect or edit them manually.

Schema

Python output reference

Every exported file follows the same template. Understanding it helps you extend or debug generated code.

# Generated by Buildfy v3.0
# Requirements: pip install customtkinter
import customtkinter as ctk
import tkinter as tk

ctk.set_appearance_mode("dark")         # "dark" | "light" | "system"
ctk.set_default_color_theme("blue")    # from Base Properties > Color


class App(ctk.CTk):
    def __init__(self):
        super().__init__()
        self.title("My Application")
        self.geometry("800x600")
        self.resizable(True, True)
        self._setup_widgets()
        self._setup_events()  # only if node graph is non-empty

    def _setup_widgets(self):
        # ── Widgets ────────────────────────────────
        self.button_a1b2 = ctk.CTkButton(
            self, width=120, height=36,
            text="Click Me",
            fg_color="#F0525C",
            font=("Inter", 13)
        )
        self.button_a1b2.place(x=120, y=80)   # x and y ONLY
        self._button_a1b2_x = 120             # stored for show/hide
        self._button_a1b2_y = 80

        # post-placement value calls:
        self.slider_b2c3.set(50)              # CTkSlider
        self.pb_c3d4.set(0.7)                # CTkProgressBar
        self.switch_d4e5.select()             # CTkSwitch (on)

    def _setup_events(self):
        # Generated from node editor
        self.button_a1b2.configure(
            command=self._button_a1b2_click
        )

    def _button_a1b2_click(self):
        self.label_e5f6.configure(text="Clicked!")


def main():
    app = App()
    app.mainloop()


if __name__ == "__main__":
    main()

FAQ

My app crashes with "width and height must be passed to the constructor"

You (or a previous version of Buildfy) generated code with width= and height= inside the .place() call. CustomTkinter forbids this. Move them to the widget constructor: ctk.CTkButton(self, width=120, height=36, ...), and use only x= and y= in .place().

My app crashes with "'value' are not supported arguments"

CTkProgressBar, CTkSlider, CTkSwitch, and CTkCheckBox do not accept value= in their constructors. Remove it and add a .set() or .select() call after the .place() call.

CTkRadioButton crashes on launch

RadioButtons require a shared tk.IntVar. Declare it before the widget: self.rb_var = tk.IntVar(value=0), then pass variable=self.rb_var to each button in the group.

Node connections don't stick

Drag from an output port (right side, colored circle) to an input port (left side, gray circle). Make sure to release the mouse directly on the target port. The connection appears as a colored Bezier curve.

Can I use Buildfy offline?

Buildfy is a browser-based app and requires an internet connection to load. Once loaded, most editing features work without network access. Saving files downloads them to your machine so they are always available locally.

What Python version do I need?

Python 3.10 or later is recommended. CustomTkinter 5.x requires Python 3.8 minimum, but several features behave best on 3.10+.