Pyzed vs Dear PyGui

Dear PyGui wraps Dear ImGui, the immediate-mode toolkit used for debug tools in game engines. It is GPU-drawn and very fast, and it shines for real-time plots, node editors and internal tools. Its look is the ImGui “tool” look, and it redraws continuously, which suits a dashboard that changes every frame more than a form that changes when you click.

In short

	Pyzed	Dear PyGui
Model	State + `view()` (Elm architecture)	Items created once with tags, changed with `set_value` / `configure_item`
Redraws	When something changes	Every frame, by default
Look	Modern ready-made components, themes, dark mode	ImGui tool style, configurable with themes
Text	Full shaping, any script, emoji, rich text and markdown	Fonts and glyph ranges you load yourself
Plots	Sparklines, bar and donut charts, a canvas	Excellent built-in plotting (ImPlot)
Desktop features	Menus, shortcuts, multi-window, docks, code editor	Docking and viewports from ImGui
Designer, hot reload	Pyzed Design, `pyzed dev`	–
Accessibility	Keyboard; no screen readers yet	No screen readers

The same counter

"""Reference app: a counter with -, + and Reset."""

import pyzed as pz
from pyzed import ui


class Counter(pz.App):
    title = "Counter"
    size = (320, 200)

    def __init__(self):
        self.count = 0

    def add(self, step):
        self.count += step

    def view(self):
        return pz.center(pz.column([
            ui.heading(str(self.count)),
            pz.row([
                ui.button(icon="minus", on_press=lambda: self.add(-1)),
                ui.button(icon="plus", on_press=lambda: self.add(1), variant="solid"),
                ui.button("Reset", lambda: setattr(self, "count", 0), variant="ghost"),
            ], spacing=8),
        ], spacing=16, align="center"))


pz.run(Counter)

"""Reference app: a counter with -, + and Reset."""

import dearpygui.dearpygui as dpg

dpg.create_context()
count = 0


def change(step):
    global count
    count = 0 if step is None else count + step
    dpg.set_value("count", str(count))


with dpg.window(tag="main"):
    dpg.add_text("0", tag="count")
    with dpg.group(horizontal=True):
        dpg.add_button(label="-", callback=lambda: change(-1))
        dpg.add_button(label="+", callback=lambda: change(1))
        dpg.add_button(label="Reset", callback=lambda: change(None))
dpg.create_viewport(title="Counter", width=320, height=200)
dpg.setup_dearpygui()
dpg.show_viewport()
dpg.set_primary_window("main", True)
dpg.start_dearpygui()
dpg.destroy_context()

The same to-do list

"""Reference app: add tasks (button or Enter), tick them off, delete them, see how many are left."""

import pyzed as pz
from pyzed import ui


class Todo(pz.App):
    title = "To-do"
    size = (420, 480)

    def __init__(self):
        self.tasks = []  # [title, done]
        self.draft = ""

    def add(self):
        if self.draft.strip():
            self.tasks.append([self.draft.strip(), False])
            self.draft = ""

    def toggle(self, task, done):
        task[1] = done

    def row(self, task):
        return pz.row([
            ui.checkbox(task[1], lambda done: self.toggle(task, done)),
            ui.label(task[0], color="text_muted" if task[1] else "text", width="fill"),
            ui.icon_button("trash-2", lambda: self.tasks.remove(task)),
        ], spacing=8, align="center")

    def view(self):
        left = sum(not done for _, done in self.tasks)
        return pz.column([
            ui.heading(f"{left} left", level=3),
            pz.row([
                ui.input(self.draft, lambda text: setattr(self, "draft", text), on_submit=self.add),
                ui.button("Add", self.add, variant="solid"),
            ], spacing=8),
            pz.scrollable(pz.column([self.row(t) for t in self.tasks], spacing=4), height="fill"),
        ], spacing=12, padding=16)


pz.run(Todo)

"""Reference app: add tasks (button or Enter), tick them off, delete them, see how many are left."""

import dearpygui.dearpygui as dpg

dpg.create_context()
tasks = []  # [title, done]


def refresh():
    dpg.delete_item("list", children_only=True)
    for task in tasks:
        with dpg.group(horizontal=True, parent="list"):
            dpg.add_checkbox(label=task[0], default_value=task[1],
                             callback=lambda s, value, t=task: (t.__setitem__(1, value), refresh()))
            dpg.add_button(label="Delete", callback=lambda s, a, t=task: (tasks.remove(t), refresh()))
    dpg.set_value("left", f"{sum(not done for _, done in tasks)} left")


def add():
    text = dpg.get_value("entry").strip()
    if text:
        tasks.append([text, False])
        dpg.set_value("entry", "")
        refresh()


with dpg.window(tag="main"):
    dpg.add_text("0 left", tag="left")
    with dpg.group(horizontal=True):
        dpg.add_input_text(tag="entry", width=300, on_enter=True, callback=add)
        dpg.add_button(label="Add", callback=add)
    dpg.add_child_window(tag="list")
dpg.create_viewport(title="To-do", width=420, height=480)
dpg.setup_dearpygui()
dpg.show_viewport()
dpg.set_primary_window("main", True)
dpg.start_dearpygui()
dpg.destroy_context()

Measured

Medians from the benchmarks (Linux, no GPU: both render through Mesa’s software drivers).

Measurement (lower is better in every row)	Pyzed 1.2.0	Dear PyGui 2.3.1
Import the library	35 ms	17 ms
First frame, 10 rows	165 ms	133 ms
First frame, 1,000 rows	243 ms	152 ms
Memory (RSS), 10 rows	151 MB	123 MB
Memory (RSS), 1,000 rows	161 MB	125 MB
Update 1,000 rows	18 ms	6.6 ms
Lines: counter	19 lines	19 lines
Lines: to-do list	31 lines	29 lines

From Dear PyGui concepts to Pyzed

Dear PyGui	Pyzed
`create_context`, `create_viewport`, `start_dearpygui`	`pz.run(MyApp)`
`with dpg.window(...)`	the root returned by `view()`
`dpg.add_text(tag="x")` + `dpg.set_value("x", ...)`	`ui.label(self.x)`: change `self.x`
`callback=fn`	`on_press=fn`
`dpg.group(horizontal=True)`	`pz.row`
`dpg.child_window`	`pz.scrollable`, `ui.card`, `ui.panel`
`dpg.theme()` + `bind_item_theme`	themes and styles
`dpg.add_plot`	`ui.bar_chart`, `ui.sparkline`, or `pz.canvas` for custom drawing

When to choose which

Choose Dear PyGui for real-time plots, node editors, instrument panels and debug tools where the ImGui look is fine.
Choose Pyzed for end-user apps: forms, lists, editors and dashboards that should look polished, with proper text, a designer, hot reload and packaging.