Why Is Canvas So Big Unity

Unity3D, a robust game development engine, offers a wide range of tools and functions that assist developers in crafting captivating gaming adventures. One crucial element is its UI system, where the Canvas plays a significant role. However, novice developers may question, “Why is the Canvas in Unity so large?”

Let’s delve into this and understand why the tool behaves this way.

Understanding Canvas in Unity

Canvas is the area that contains all the UI elements in your game. It is like a “drawing board”, which is used for laying down the UI elements, including text, images, buttons, etc. The size and position of the Canvas can dramatically affect the appearance of UI elements.

Why is the Canvas so Big?

When you first create a new Canvas, you’ll notice that it appears extremely large and extends beyond the scene’s view in Unity. This is because the Canvas’s size in Unity isn’t fixed and can dynamically adjust to the screen resolution of the game window. Its default size is 1920×1080 pixels, which corresponds to a typical Full HD screen.

This large size ensures that UI components are appropriately visible, regardless of the resolution. So, the big Canvas size isn’t an issue, rather it’s a feature designed to make the UI adaptive to different screen resolutions.

Configuring the Canvas Size

Even though the Canvas size in Unity is big, developers can adjust it according to their needs. The Canvas Scaler component, attached to the Canvas object, controls this. It has three scale modes:

  • Constant Pixel Size
  • Scale With Screen Size
  • Constant Physical Size

Each mode affects how UI elements are displayed on different screen resolutions and aspect ratios. Let’s look at an example of how to configure the Canvas size using the ‘Scale With Screen Size’ mode.

CanvasScaler canvasScaler = canvasObject.GetComponent<canvasscaler>();
canvasScaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
canvasScaler.referenceResolution = new Vector2(800, 600); // change this according to your needs

Here, we first get the CanvasScaler component from the Canvas object. We then set the scale mode to ‘Scale With Screen Size’, which automatically scales the UI layout and adjusts the Canvas size based on the screen resolution. We can specify the Reference Resolution to define the resolution the layout is designed for.


In conclusion, while the large size of Canvas in Unity might seem strange at first, it’s actually a feature designed to handle different screen resolutions gracefully. Through its flexibility and adaptability, it ensures that your game’s UI remains consistent across various platforms and screen sizes. Happy game development in Unity!