5 Python GUI Libraries That Make UI Development Fun (Beyond Tkinter)

Why move away from Tkinter

Tkinter’s layout management and styling are cumbersome, making simple GUIs feel outdated. Modern Python GUI libraries provide faster development, richer widgets, and better theming.

1. PyQt6 – Professional‑grade desktop UI

Core advantages

True cross‑platform support

Extensive widget set and powerful layout system

CSS‑style theming via Qt Style Sheets

Robust signal‑slot mechanism for event handling

Quick‑start example

import sys
from PyQt6.QtWidgets import QApplication, QWidget, QLabel, QPushButton, QVBoxLayout

app = QApplication(sys.argv)
window = QWidget()
window.setWindowTitle("PyQt6 Quick Start")
window.setGeometry(100, 100, 300, 200)

layout = QVBoxLayout()
label = QLabel("Welcome to PyQt6!")
button = QPushButton("Click Me")

def on_button_click():
    label.setText("Button clicked!")

button.clicked.connect(on_button_click)
layout.addWidget(label)
layout.addWidget(button)
window.setLayout(layout)
window.show()
sys.exit(app.exec())

Usage insights

Learning curve: moderate – initial effort to grasp signal‑slot patterns, then high productivity.

Best suited for professional desktop applications and complex enterprise tools.

2. Dear PyGui – GPU‑accelerated lightweight GUI

Distinctive features

Game‑engine based rendering architecture provides GPU acceleration for all widgets.

Rich built‑in data‑visualization components (charts, progress bars, etc.).

Very high performance, ideal for real‑time monitoring panels.

Data‑monitoring panel example

import dearpygui.dearpygui as dpg
import random, time

dpg.create_context()

def update_data():
    current_time = time.strftime("%H:%M:%S")
    cpu = random.randint(20, 90)
    mem = random.randint(30, 85)
    dpg.set_value("time_text", f"Time: {current_time}")
    dpg.set_value("cpu_bar", cpu/100)
    dpg.set_value("cpu_value", f"CPU: {cpu}%")
    dpg.set_value("mem_bar", mem/100)
    dpg.set_value("mem_value", f"Mem: {mem}%")

with dpg.window(label="System Monitor", width=400, height=300):
    dpg.add_text("System Status", color=(0,0,255))
    dpg.add_separator()
    dpg.add_text("", tag="time_text")
    dpg.add_text("CPU Usage")
    dpg.add_progress_bar(tag="cpu_bar", width=300)
    dpg.add_text("", tag="cpu_value")
    dpg.add_text("Memory Usage")
    dpg.add_progress_bar(tag="mem_bar", width=300)
    dpg.add_text("", tag="mem_value")
    dpg.add_button(label="Start", width=100)
    dpg.add_button(label="Stop", width=100)

dpg.set_frame_callback(10, update_data)

dpg.create_viewport(title='System Monitor', width=420, height=350)

dpg.setup_dearpygui()

dpg.show_viewport()

dpg.start_dearpygui()

dpg.destroy_context()

Recommended scenarios

Internal monitoring tools that require real‑time updates.

Adding a UI layer to automation scripts.

Rapid prototyping of data‑heavy interfaces.

3. Flet – Build web apps with pure Python

Key benefits

Write once, deploy to web, desktop, and mobile (Flutter backend).

Material Design components are available out of the box.

Responsive layout system requires no manual CSS or JavaScript.

File‑manager example

import flet as ft
import os
from pathlib import Path

def main(page: ft.Page):
    page.title = "Python File Manager"
    page.theme_mode = ft.ThemeMode.DARK
    page.padding = 20
    current_path = ft.Text(value=f"Current dir: {os.getcwd()}", size=16)
    file_list = ft.Column()

    def list_files():
        file_list.controls.clear()
        if Path.cwd().parent != Path.cwd():
            file_list.controls.append(
                ft.ListTile(
                    leading=ft.Icon(ft.icons.FOLDER_OPEN),
                    title=ft.Text(".. (Parent)"),
                    on_click=lambda e: change_directory(Path.cwd().parent)
                )
            )
        for item in sorted(Path.cwd().iterdir()):
            icon = ft.icons.FOLDER if item.is_dir() else ft.icons.INSERT_DRIVE_FILE
            color = ft.colors.BLUE_200 if item.is_dir() else ft.colors.WHITE
            file_list.controls.append(
                ft.ListTile(
                    leading=ft.Icon(icon, color=color),
                    title=ft.Text(item.name),
                    subtitle=ft.Text(f"Size: {item.stat().st_size:,} bytes" if item.is_file() else "Directory"),
                    on_click=lambda e, p=item: open_item(p)
                )
            )
        page.update()

    def change_directory(new_path):
        os.chdir(new_path)
        current_path.value = f"Current dir: {os.getcwd()}"
        list_files()

    def open_item(item_path):
        if item_path.is_dir():
            change_directory(item_path)
        else:
            page.show_snack_bar(ft.SnackBar(ft.Text(f"Opening file: {item_path.name}")))

    list_files()
    page.add(ft.Text("Python File Manager", size=24, weight=ft.FontWeight.BOLD))
    page.add(current_path)
    page.add(ft.Divider())
    page.add(ft.Container(content=file_list, height=400, border=ft.border.all(1, ft.colors.GREY_800), border_radius=10, padding=10))
    page.add(ft.Row([
        ft.ElevatedButton("Refresh", icon=ft.icons.REFRESH, on_click=lambda e: list_files()),
        ft.ElevatedButton("About", icon=ft.icons.INFO, on_click=lambda e: page.show_dialog(ft.AlertDialog(title=ft.Text("About"), content=ft.Text("File manager built with Flet"))))
    ]))

ft.app(target=main)

Best fit

Full‑stack Python developers who want to avoid front‑end technologies.

Quick prototyping of web interfaces (minutes to a usable UI).

Internal tools that need to be shared across a team.

4. Textual – Modern TUI for the terminal

Why use Textual

Preserves the full terminal workflow while providing GUI‑like widgets.

SSH‑friendly; remote servers can display the interface without X forwarding.

Very low resource consumption compared to graphical toolkits.

Automation task manager example

from textual.app import App, ComposeResult
from textual.widgets import Header, Footer, Button, Static, Label
from textual.containers import Container, Vertical
import asyncio

class TaskManager(App):
    """Task manager application"""
    CSS = """
    Screen { background: $surface; }
    .task-container { height: 1fr; border: solid $primary; padding: 1; }
    .success { color: $success; }
    .error { color: $error; }
    .running { color: $warning; }
    """

    def compose(self) -> ComposeResult:
        yield Header()
        with Container(id="main-container"):
            with Vertical(id="left-panel"):
                yield Label("Automation Task Manager", classes="title")
                yield Button("Run Data Clean", id="clean-data", variant="primary")
                yield Button("Generate Report", id="generate-report", variant="success")
                yield Button("Backup DB", id="backup-db", variant="warning")
            with Vertical(id="right-panel", classes="task-container"):
                yield Label("Task Status", classes="subtitle")
                yield Static("", id="status-display")
        yield Footer()

    def on_button_pressed(self, event: Button.Pressed) -> None:
        button_id = event.button.id
        status_display = self.query_one("#status-display")
        if button_id == "clean-data":
            status_display.update("[bold]Cleaning data...[/]")
            self.run_task(self.simulate_task, "Data Clean", 3)
        elif button_id == "generate-report":
            status_display.update("[bold]Generating report...[/]")
            self.run_task(self.simulate_task, "Report", 2)
        elif button_id == "backup-db":
            status_display.update("[bold]Backing up DB...[/]")
            self.run_task(self.simulate_task, "DB Backup", 4)

    async def simulate_task(self, task_name: str, duration: int) -> None:
        status_display = self.query_one("#status-display")
        for i in range(duration):
            status_display.update(f"[bold]{task_name} running... ({i+1}/{duration}s)[/]")
            await asyncio.sleep(1)
        status_display.update(f"[bold green]✓ {task_name} completed![/]")

if __name__ == "__main__":
    app = TaskManager()
    app.run()

Ideal use cases

Server‑management tools accessed via SSH.

Enhancing existing CLI utilities with interactive UI.

Developing auxiliary tools such as linters or test runners.

5. CustomTkinter – Modernising classic Tkinter

What it provides

Material‑Design styling and built‑in dark theme.

Improved layout handling through CTkTabview and CTk widgets.

Minimal code changes required for existing Tkinter projects.

Modern settings panel example

import customtkinter as ctk
import tkinter as tk
from tkinter import messagebox

class SettingsApp:
    def __init__(self):
        ctk.set_appearance_mode("dark")
        ctk.set_default_color_theme("blue")
        self.app = ctk.CTk()
        self.app.title("Modern Settings Panel")
        self.app.geometry("500x400")
        self.tabview = ctk.CTkTabview(self.app)
        self.tabview.pack(fill="both", expand=True, padx=20, pady=20)
        self.tabview.add("General")
        self.tabview.add("Appearance")
        self.tabview.add("About")
        self.setup_general_tab()
        self.setup_appearance_tab()
        self.setup_about_tab()

    def setup_general_tab(self):
        tab = self.tabview.tab("General")
        self.auto_start = ctk.CTkSwitch(tab, text="Auto‑Start on Boot", command=self.on_auto_start_change)
        self.auto_start.pack(pady=10, anchor="w", padx=20)
        self.auto_update = ctk.CTkSwitch(tab, text="Check for Updates")
        self.auto_update.pack(pady=10, anchor="w", padx=20)
        ctk.CTkLabel(tab, text="Log Level:").pack(pady=(20,5), anchor="w", padx=20)
        self.log_level = ctk.CTkComboBox(tab, values=["DEBUG","INFO","WARNING","ERROR"])
        self.log_level.pack(pady=5, anchor="w", padx=20, fill="x")

    def setup_appearance_tab(self):
        tab = self.tabview.tab("Appearance")
        ctk.CTkLabel(tab, text="Theme Mode:").pack(pady=10, anchor="w", padx=20)
        self.theme_mode = ctk.CTkSegmentedButton(tab, values=["Light","Dark","System"], command=self.on_theme_change)
        self.theme_mode.set("Dark")
        self.theme_mode.pack(pady=5, anchor="w", padx=20, fill="x")
        ctk.CTkLabel(tab, text="Color Theme:").pack(pady=10, anchor="w", padx=20)
        self.color_theme = ctk.CTkComboBox(tab, values=["Blue","Green","Purple","Orange"])
        self.color_theme.pack(pady=5, anchor="w", padx=20, fill="x")

    def setup_about_tab(self):
        tab = self.tabview.tab("About")
        info_text = """
Modern Settings Panel Example

Version: 1.0.0
Author: 云朵君

Built with CustomTkinter for a modern UI experience
"""
        ctk.CTkLabel(tab, text=info_text, justify="left").pack(pady=20, padx=20)
        btn_frame = ctk.CTkFrame(tab)
        btn_frame.pack(pady=20)
        ctk.CTkButton(btn_frame, text="Check Updates", width=100).pack(side="left", padx=10)
        ctk.CTkButton(btn_frame, text="Visit Website", width=100).pack(side="left", padx=10)

    def on_auto_start_change(self):
        status = "On" if self.auto_start.get() else "Off"
        print(f"Auto‑Start: {status}")

    def on_theme_change(self, value):
        mapping = {"Light": "light", "Dark": "dark", "System": "system"}
        ctk.set_appearance_mode(mapping[value])
        print(f"Theme switched to: {value}")

    def run(self):
        self.app.mainloop()

if __name__ == "__main__":
    app = SettingsApp()
    app.run()

When to use

Modernising existing Tkinter projects with minimal code changes.

Quickly adding a polished UI to legacy tools.

Decision guide

Flet – choose for web or multi‑platform apps.

Dear PyGui – choose for high‑performance monitoring dashboards.

PyQt6 – choose for professional desktop software.

Textual – choose to enhance existing command‑line utilities.

CustomTkinter – choose to modernise an existing Tkinter project.

Migrating from Tkinter

Gradual migration – replace widgets step‑by‑step with CustomTkinter equivalents.

Unified styling – use the built‑in theme system to keep a consistent look.

Feature boost – gain a modern appearance while preserving the original code structure.