iced

Elm-inspired reactive GUIs in Rust - explicit messages, immutable updates, and native widgets.

Recipe

use iced::widget::{button, column, text};
use iced::Element;
 
pub fn update(count: &mut i32, message: Message) {
    match message {
        Message::Increment => *count += 1,
    }
}
 
pub fn view(count: &i32) -> Element<Message> {
    column![
        text(format!("{count}")),
        button("+").on_press(Message::Increment),
    ]
    .into()
}

When to reach for this:

• Consumer desktop apps without HTML
• Teams liking Redux/Elm unidirectional data flow
• Cross-platform apps needing consistent custom styling
• Tutorial-friendly architecture for junior Rust devs

Working Example

use iced::widget::{button, column, text, Column};
use iced::{application, Element};
 
#[derive(Debug, Clone)]
enum Message {
    Increment,
    Decrement,
}
 
struct Counter {
    value: i32,
}
 
impl Counter {
    fn new() -> Self {
        Self { value: 0 }
    }
 
    fn update(&mut self, message: Message) {
        match message {
            Message::Increment => self.value += 1,
            Message::Decrement => self.value -= 1,
        }
    }
 
    fn view(&self) -> Element<Message> {
        column![
            text(format!("{}", self.value)),
            button("+").on_press(Message::Increment),
            button("-").on_press(Message::Decrement),
        ]
        .into()
    }
}
 
fn main() -> iced::Result {
    application("Counter", Counter::update, Counter::view)
        .run_with(Counter::new)
}

What this demonstrates:

• application helper wiring update/view
• Separate increment/decrement messages
• Column layout composing widgets

Deep Dive

How It Works

• Runtime receives OS events, converts to Message.
• update mutates model; view rebuilds Element tree.
• Diffing renderer minimizes GPU work (wgpu backend).
• Subscription streams external events (time, keyboard).

Architecture Pieces

Gotchas

• Large view functions - hard to maintain. Fix: split into submodules returning Element.
• Forgetting subscription - timers never fire. Fix: wire application::subscription when using async sources.
• Clone on every message - heavy models hurt. Fix: use Arc for read-only chunks in model.
• Platform font rendering - verify CJK on all targets. Fix: custom font loading in settings.
• ** iced 0.13 API changes** - pin book/tutorial version to crate version.

Alternatives

FAQs

Related

• GUI Basics - iced counter intro
• State & Architecture - scaling MVU
• egui - immediate-mode alternative
• Packaging & Distribution - releases

Stack versions: This page was written for Rust 1.97.0 (edition 2024), Tokio 1.x, Axum 0.8, serde 1.0, sqlx 0.8, clap 4, and Polars 0.46+.