The two ways to resize your canvas in Photoshop
Photoshop gives you two separate tools for changing canvas size, and they do different things. Image > Canvas Size keeps your image content the same and adds or removes space around it — useful when you need more room for text, a border, or to fit a specific frame size. Image > Scale Image stretches or shrinks your actual image content to fit a smaller or larger canvas — useful when you need to make the whole thing bigger or smaller.
Most people reach for Canvas Size when they want to add white space or change the proportions of their frame without losing detail in the photo itself. You would use Scale Image if you're preparing a photo for print at a different size, or if you need the entire image smaller to fit a web layout.
Key Takeaways
- Canvas Size adds or removes space around your image without changing the image itself; Scale Image shrinks or enlarges the actual photo content.
- In the Canvas Size dialog, you set new dimensions in pixels or inches, then use the anchor grid to choose where your original image sits in the new space.
- If you add canvas space, Photoshop fills it with your current background color — usually white — unless you flatten the image first.
- Canvas Size works on a single layer; if you have multiple layers, only the active layer gets resized, and you may need to resize all layers to match.
- The Image menu is where both tools live; neither one is in the Tools panel or the right-side panels.
How to add or remove canvas space with Canvas Size
Open your image in Photoshop and go to Image > Canvas Size. A dialog box opens showing your current dimensions — usually in pixels, but you can change the unit to inches, centimeters, or other measurements by clicking the dropdown next to the number.
Enter your new width and height. If you want to add space, make the numbers larger. If you want to crop away space without losing the image, make them smaller. Below the dimension fields, you'll see a small grid with a square in the middle — this is your anchor point. Click any square in the grid to tell Photoshop where to position your original image inside the new canvas. If you click the center square, your image stays centered and space gets added equally on all sides. If you click the top-left square, your image stays in the top-left corner and new space appears on the right and bottom.
The Canvas extension color dropdown at the bottom of the dialog lets you choose what color fills the new space. The default is your current background color. If you want white space and your background is set to something else, change it here before you click OK. Once you click OK, the canvas resizes and your image sits in the position you chose.
How to resize your entire image with Scale Image
Go to Image > Scale Image. This dialog shows your current width and height. Change either number to your target size. By default, the width and height are linked — you'll see a chain icon between them — so changing one automatically adjusts the other to keep your image proportions the same. If you want to stretch or squash the image, click the chain to unlink them, then set width and height independently.
The Resample dropdown at the bottom matters when you're making an image larger. Photoshop has to guess what new pixels should look like. "Bicubic Sharper" works well for making images smaller. "Bicubic" is the middle ground. If you're enlarging significantly, "Preserve Details" or "Super Resolution" (in newer versions) produces better results, though Super Resolution can take a minute to process. Click OK and your entire image scales to the new size.
What happens to layers when you change canvas size
Canvas Size only resizes the active layer — the one highlighted in your Layers panel. If you have multiple layers and you resize the canvas, only the selected layer changes size. The other layers stay their original size, which can create a misaligned mess.
To resize all layers at once, go to Image > Flatten Image first. This merges all layers into one. Then use Canvas Size or Scale Image. If you're not ready to flatten because you still need to edit layers separately, resize each layer individually by selecting it and repeating the Canvas Size step, or use Image > Scale Image, which scales the entire image and all its layers together.
Adding canvas space without a background color
When you add canvas space using Canvas Size, Photoshop fills the new area with your background color. If you want transparent space instead — so you can see through to whatever's behind the image in your design — you need to work with layers differently.
Before you resize the canvas, make sure your image is on a layer with transparency. If it's a flattened image or a background layer, go to Layer > New > Layer from Visible to convert it. Then use Canvas Size as normal. The new space will be transparent instead of filled with color. You can always add a new layer below it and fill that layer with color or a pattern later if you change your mind.
Common mistakes and how to avoid them
The most common mistake is using Canvas Size when you meant to use Scale Image, or vice versa. If you add canvas space and then realize you wanted the image itself bigger, you've wasted time. Before you open either dialog, ask yourself: do I want more room around the image, or do I want the image itself larger? That answer tells you which tool to use.
Another mistake is forgetting that Canvas Size only affects the active layer. You resize the canvas, flatten the image later, and suddenly parts of your layers are cut off because they weren't resized when the canvas was. If you have multiple layers, flatten first or resize all layers individually.
A third mistake is not checking your background color before adding canvas space. You set up a canvas size, click OK, and get a bright magenta border instead of white because your background color was set to magenta. Check the foreground and background color squares in your toolbox before you resize, or use the Canvas extension color dropdown to override it.
Resizing canvas for specific print or web sizes
If you're preparing an image for print, you often need specific dimensions in inches at a certain resolution. Open Canvas Size and change the unit dropdown from pixels to inches. Set your width and height in inches — for example, 8 by 10 for a standard print size. The resolution field shows your current DPI (dots per inch). For print, 300 DPI is standard. For web, 72 DPI is typical, though modern screens vary.
For web, work in pixels. A social media profile photo might be 400 by 400 pixels. A banner might be 1200 by 300 pixels. Set your canvas size in pixels, position your image using the anchor grid, and you're ready to export. Use File > Export As to save it as a JPG or PNG for the web.
Frequently Asked Questions
Can I undo a canvas size change?
Yes. Use Edit > Undo or press Ctrl+Z (Windows) or Command+Z (Mac) when ready after resizing. If you've made other edits since then, you can step back through your history in the History panel on the right side of the screen.
What's the difference between canvas size and image size?
Canvas size changes the frame around your image without changing the image itself. Image size (Scale Image) changes the actual image content. Think of canvas as the mat around a photo and image as the photo itself.
Why does my canvas size dialog show different units than I expect?
The unit dropdown in the Canvas Size dialog controls what you see. Click it and select pixels, inches, centimeters, or another unit. Your choice here doesn't change the image — it just changes how you enter the numbers.
Can I add canvas space on just one side of my image?
Yes, using the anchor grid. If you want space only on the right and bottom, click the top-left square in the anchor grid before you click OK. Your image stays in the top-left corner and new space appears only on the right and bottom.
What happens if I make the canvas smaller than my image?
Photoshop crops your image to fit the new canvas size. The parts that fall outside the new canvas boundaries are hidden, not deleted. If you undo when ready, you get them back. If you flatten the image first, the crop becomes permanent.