# Pyzed vs tkinter — a modern tkinter alternative

> Pyzed vs tkinter (and CustomTkinter) for Python desktop apps: the same apps side by side, measured startup, memory and speed, concept mapping and how to migrate from tkinter to Pyzed.

Source: https://albakore.github.io/pyzed/why/vs-tkinter/

[tkinter](https://docs.python.org/3/library/tkinter.html) is the GUI toolkit that comes with Python. It is
everywhere, it is small and it is fast to start, which is why most people meet it first. It also shows
its age: widgets that look like the 2000s, a layout model split between `pack`, `grid` and `place`, and no
answer for dark mode, hot reload or a visual designer.
[CustomTkinter](https://customtkinter.tomschimansky.com) modernises the look on top of tkinter, and is
included in the numbers below too.

## In short

| | Pyzed | tkinter |
| --- | --- | --- |
| Install | `pip install pyzed-ui` | Already there (on Linux, sometimes a `python3-tk` package) |
| Look | Modern ready-made components, themes, dark mode | Classic Tk, or `ttk` themes |
| Programming model | State + `view()`: the UI is rebuilt from your data | Widgets you create, keep references to and mutate |
| Layout | Rows, columns, grids, stacks, docks, anchors | `pack`, `grid`, `place` |
| Drawing | GPU (wgpu), CPU fallback | Tk, on the CPU |
| Designer, hot reload | Pyzed Design, `pyzed dev` | Third-party designers; no hot reload |
| Rich widgets | Code editor, command palette, file tree, tabs, toasts, markdown… | Text, Canvas, Treeview; the rest is DIY |
| Accessibility | Keyboard; no screen readers yet | Limited |

## The same counter

Both files are the reference apps from [the benchmarks](https://albakore.github.io/pyzed/why/benchmarks/), counted line by line.

## The same to-do list

Add with the button or <kbd>Enter</kbd>, tick tasks off, delete them, and show how many are left. In
tkinter, keeping the screen in sync with the data is your job (`refresh()` destroys and recreates the rows);
in Pyzed, `view()` always describes the current data.

## Measured

Medians from [the benchmarks](https://albakore.github.io/pyzed/why/benchmarks/) (Linux, no GPU: software rendering, which penalises
Pyzed's GPU renderer and favours tkinter's CPU drawing).

tkinter wins on startup and size: it is a few megabytes of C that is already loaded with Python, and it
draws with the CPU, which is exactly what a machine without a GPU does well. Pyzed brings a GPU renderer,
a text engine and dozens of components, and still opens a 1,000-row window in a fraction of a second.

## From tkinter concepts to Pyzed

| tkinter | Pyzed |
| --- | --- |
| `root = tk.Tk()` … `root.mainloop()` | `class MyApp(pz.App)` … `pz.run(MyApp)` |
| `root.title(...)`, `root.geometry("400x300")` | class attributes `title = ...`, `size = (400, 300)` |
| `tk.StringVar`, `IntVar` | plain attributes: `self.name = ""` |
| `widget.configure(text=...)` | change the attribute; `view()` shows it |
| `ttk.Label`, `ttk.Button`, `ttk.Entry` | `ui.label`, `ui.button`, `ui.input` |
| `command=callback` | `on_press=callback` (or a message for `update()`) |
| `pack(side="left")` / `grid(row, column)` | `pz.row([...])`, `pz.column([...])`, `pz.grid(...)` |
| `Canvas` + `Scrollbar` + inner `Frame` | `pz.scrollable(...)` |
| `ttk.Treeview` | [`ui.tree`](https://albakore.github.io/pyzed/library/tree/), [`ui.table`](https://albakore.github.io/pyzed/library/table/) |
| `root.after(ms, fn)` | `pz.every(seconds, message)` in `subscriptions()`, or an `async` callback |
| `messagebox` | [`ui.confirm`](https://albakore.github.io/pyzed/library/confirm/), [`ui.prompt`](https://albakore.github.io/pyzed/library/prompt/), [`ui.modal`](https://albakore.github.io/pyzed/library/modal/) |
| `filedialog` | No native file dialog yet: use a [`ui.tree`](https://albakore.github.io/pyzed/library/tree/) of files or keep a helper library for it |
| `ttk.Style` | [themes](https://albakore.github.io/pyzed/theming/themes/) and [styles](https://albakore.github.io/pyzed/theming/styles/) |

## Migration tips

1. **Move state out of the widgets.** Every `StringVar`, `IntVar` and every value you read with `.get()`
   becomes an attribute of your `App`. That is most of the work.
2. **Replace update code with `view()`.** Functions that destroy and rebuild frames, or `configure` labels,
   disappear: write `view()` once from the attributes.
3. **Map layouts one-to-one.** A `Frame` packed horizontally is a `pz.row`, vertically a `pz.column`; `grid`
   becomes `pz.grid`; spacing and padding are arguments instead of `padx`/`pady` on every widget.
4. **Timers and threads.** `root.after` loops become `subscriptions()`; long work goes in an `async def`
   callback or a thread, and its result comes back as a message.
5. **Keep tkinter where it fits.** A five-line dialog in a script that must run on a bare Python is still a
   good tkinter use case.

## When to choose which

- **Choose tkinter** for tiny utilities and teaching material that must run with nothing installed, or when
  your users need screen readers on platforms where Tk supports them.
- **Choose Pyzed** when the app should look current, grow beyond a few windows, be designed visually, reload
  while you work and ship as a polished executable.