Open the Canvas Size dialog from the Image menu

To change your canvas size in Aseprite, go to Image in the top menu bar, then select Canvas Size. A dialog box will open showing your current canvas dimensions in pixels. You can change the width and height to any size you need.

The dialog displays your current size and lets you set a new one. You can type the exact pixel dimensions you want, or use the arrow buttons to adjust by single pixels. The preview in the dialog shows where your existing artwork will sit on the new canvas.

Key Takeaways

  • Canvas size is found under Image > Canvas Size in the menu bar, and it changes only the workspace around your art, not the art itself.
  • You can set exact pixel dimensions and choose where your existing artwork will be positioned on the new canvas using the anchor point.
  • The offset fields let you move your artwork left, right, up, or down within the new canvas boundaries.
  • Aseprite fills empty canvas space with your current background color, which you can change before or after resizing.

Position your artwork on the new canvas using the anchor

Below the width and height fields, you will see a grid with nine small squares. This is the anchor point, and it controls where your existing artwork sits on the new canvas. Click any of the nine positions to anchor your art to that spot.

If you click the center square, your artwork stays centered and the canvas expands equally on all sides. If you click the top-left square, your artwork stays in the top-left corner and the canvas expands to the right and down. This is useful when you know exactly where you want your art positioned and want the rest of the space to be empty.

Use offset fields to move artwork by exact pixel amounts

The Offset X and Offset Y fields let you move your artwork a precise number of pixels within the new canvas. A positive X value moves your art to the right; a negative value moves it left. A positive Y value moves it down; a negative value moves it up.

These fields are useful when you need pixel-perfect placement. For example, if you want your artwork 10 pixels from the left edge and 5 pixels from the top, you can type those values directly. The preview updates as you type, so you can see exactly where your art will end up before you confirm.

Choose what color fills the new canvas space

When you expand the canvas, Aseprite fills the new space with your current background color. Before you resize, check the color swatches at the bottom of the toolbox — the background color is the one on the right. If you want the new space to be a different color, change the background color first, then resize.

If you resize and the color is wrong, you can undo the change with Ctrl+Z (or Cmd+Z on Mac) and try again with a different background color. Alternatively, you can use the paint bucket tool to fill the new space after resizing.

Flatten or merge layers if you need to crop the canvas

Canvas Size expands or shrinks the workspace, but it does not crop artwork that extends beyond the new boundaries. If your art goes past the edge of your new canvas, that part remains in the file but becomes invisible. To permanently remove artwork outside the canvas, you need to flatten the image first.

Go to Image > Flatten Image to merge all layers and crop everything outside the canvas boundary. This is permanent, so save a copy of your file first if you might need the hidden artwork later. If you only want to crop without flattening, use Image > Crop instead, which removes the invisible area but keeps your layers intact.

Resize the canvas for specific aspect ratios or export sizes

Common canvas sizes depend on what you are making. For a 16x16 pixel sprite, your canvas is already set. For a full-screen game asset at 1920x1080, you would set those dimensions. For a square social media image, you might use 1080x1080 or 512x512.

If you are exporting to a specific format or platform, check what dimensions that platform expects, then set your canvas to match. Resizing the canvas does not change the pixel size of your artwork itself — it only changes the space around it. If you need to scale your actual art larger or smaller, use Image > Scale Image instead.

Frequently Asked Questions

What is the difference between Canvas Size and Scale Image?

Canvas Size changes the workspace around your art without changing the art itself. Scale Image makes your artwork larger or smaller. If you want more space to draw in, use Canvas Size. If you want your art to be bigger or smaller, use Scale Image.

Can I undo a canvas size change?

Yes. Press Ctrl+Z (or Cmd+Z on Mac) to undo the last canvas resize. You can undo multiple steps if needed. If you have already saved the file, you will need to reopen the saved version to get back to the original canvas size.

What happens to artwork that goes outside the new canvas?

The artwork stays in your file but becomes invisible. You can still see it if you undo or expand the canvas again. To permanently remove it, flatten the image first, then resize the canvas.

Can I change the canvas size for just one layer?

No. Canvas Size always affects the entire image and all layers at once. If you need to resize only one layer, use the layer's own crop or scale options instead, which you can find by right-clicking the layer in the Layers panel.