Skip to main content
The Settings struct configures runtime behavior for iced applications, including fonts, text rendering, and graphics options.

​
Structure Definition

#[derive(Debug, Clone)]
pub struct Settings {
    pub id: Option<String>,
    pub fonts: Vec<Cow<'static, [u8]>>,
    pub default_font: Font,
    pub default_text_size: Pixels,
    pub antialiasing: bool,
    pub vsync: bool,
}

​
Fields

​
id
Option<String>
default:"None"
The identifier of the application. If provided, this identifier may be used to identify the application or communicate with it through the windowing system.
​
fonts
Vec<Cow<'static, [u8]>>
default:"Vec::new()"
The fonts to load on boot. Add custom font files as byte arrays to make them available throughout your application.
​
default_font
Font
default:"Font::default()"
The default Font to be used. By default, it uses Family::SansSerif.
​
default_text_size
Pixels
default:"Pixels(16.0)"
The text size that will be used by default throughout the application.
​
antialiasing
bool
default:"true"
If set to true, the renderer will try to perform antialiasing for some primitives. Enabling it can produce a smoother result in some widgets, like the canvas widget, at a performance cost.
​
vsync
bool
default:"true"
Whether or not to attempt to synchronize rendering when possible. Disabling it can improve rendering performance on some platforms.

​
Default Settings

Settings::default() // Returns:
// Settings {
//     id: None,
//     fonts: Vec::new(),
//     default_font: Font::default(),
//     default_text_size: Pixels(16.0),
//     antialiasing: true,
//     vsync: true,
// }

​
Configuration with Application Builder

The Application builder provides convenient methods to configure settings:

​
Using .settings() Method

use iced::{Settings, Pixels, Font};

iced::application(State::new, update, view)
    .settings(Settings {
        id: Some("com.example.myapp".to_string()),
        default_text_size: Pixels(18.0),
        antialiasing: true,
        vsync: false,
        ..Settings::default()
    })
    .run()

​
Using Builder Methods

iced::application(State::new, update, view)
    .antialiasing(true)
    .default_font(Font::MONOSPACE)
    .font(include_bytes!("../fonts/custom-font.ttf").as_slice())
    .run()

​
Examples

​
Custom Font Loading

use iced::Font;

const CUSTOM_FONT: &[u8] = include_bytes!("../assets/CustomFont.ttf");

pub fn main() -> iced::Result {
    iced::application(State::default, update, view)
        .font(CUSTOM_FONT)
        .default_font(Font {
            family: iced::font::Family::Name("Custom Font"),
            ..Font::DEFAULT
        })
        .run()
}

​
Performance Optimization

use iced::Settings;

pub fn main() -> iced::Result {
    iced::application(State::default, update, view)
        .settings(Settings {
            antialiasing: false,  // Disable for better performance
            vsync: false,          // Disable for higher frame rates
            ..Settings::default()
        })
        .run()
}

​
Application Identifier

use iced::Settings;

pub fn main() -> iced::Result {
    iced::application(State::default, update, view)
        .settings(Settings {
            id: Some("com.mycompany.myapp".to_string()),
            ..Settings::default()
        })
        .run()
}

​
Larger Default Text Size

use iced::{Settings, Pixels};

pub fn main() -> iced::Result {
    iced::application(State::default, update, view)
        .settings(Settings {
            default_text_size: Pixels(20.0),
            ..Settings::default()
        })
        .run()
}

​
Builder Methods Reference

The Application struct provides these methods for settings configuration:
MethodDescriptionSource Location
.settings(settings)Sets all settings at once~/workspace/source/src/application.rs:213
.antialiasing(bool)Enables/disables antialiasing~/workspace/source/src/application.rs:218
.default_font(font)Sets the default font~/workspace/source/src/application.rs:229
.font(bytes)Adds a font to load at startup~/workspace/source/src/application.rs:240

​
Performance Considerations

​
Antialiasing

  • Enabled (default): Smoother appearance, especially for canvas widgets and diagonal lines
  • Disabled: Better performance, crisper edges for pixel-perfect designs

​
VSync

  • Enabled (default): Prevents screen tearing, synchronizes with display refresh rate
  • Disabled: Higher potential frame rates, may introduce tearing

​
Font Loading

Fonts are loaded at application startup. Loading many large fonts can increase startup time. Consider:
  • Only loading fonts you actually use
  • Using font subsetting to reduce file size
  • Lazy-loading fonts if possible

​
Location in Source

~/workspace/source/core/src/settings.rs:8

Build docs developers (and LLMs) love

Get started for freeTalk to us