The two ways to resize in Photoshop, and which one to use

Photoshop gives you two separate commands for changing image size, and they do different things. Image > Scale Image changes the actual pixel dimensions — use this when you need the file smaller for email or web. Image > Canvas Size changes only the workspace around the image, leaving the pixels untouched — use this when you want to add space or crop without resampling.

Most of the time you want Scale Image. It's the command that actually shrinks or enlarges the picture itself. Canvas Size is useful only when you're adding a border, preparing for text, or cropping by expanding the canvas and then flattening.

The reason this matters: scaling down loses pixel information and can't be undone perfectly later. Scaling up creates blurriness because Photoshop has to invent pixels that weren't there. Canvas Size doesn't touch the image at all — it just gives you more or less room to work.

Key Takeaways

  • Use Image > Scale Image to change the actual size of the photo; use Image > Canvas Size only to add or remove space around it.
  • Before scaling, check the resolution (pixels per inch) because scaling a 72 ppi image to print size will look blurry.
  • Turn on the chain link icon between width and height to keep proportions locked, so you don't stretch the image accidentally.
  • Scaling down is permanent and loses detail, so save a copy of the original file before you resize.
  • The Constrain Proportions checkbox and the resolution field are the two settings that matter most for avoiding distortion.

How to scale an image smaller or larger

Open your image in Photoshop. Go to Image in the menu bar, then click Scale Image. A dialog box opens showing the current width, height, and resolution.

Look at the chain link icon between the width and height fields. If it's connected (linked), changing one dimension automatically adjusts the other to keep the image proportional. This is almost always what you want — leave it linked unless you're intentionally stretching or squashing the image.

Type a new width or height in pixels, inches, or centimeters (the dropdown next to the number lets you pick the unit). The linked dimension updates automatically. If you're resizing for print, measure in inches and check that the resolution is at least 300 ppi. If you're resizing for screen, pixels are simpler — type the width you need, and the height follows.

Click OK. Photoshop resamples the image, which means it either throws away pixels (if you're going smaller) or creates new ones by guessing (if you're going larger). Smaller is always cleaner. Larger always gets softer.

Why resolution matters when you resize

The resolution field in the Scale Image dialog shows pixels per inch (ppi). This number doesn't change the file size or the pixel count — it only tells Photoshop (and printers) how densely to pack those pixels.

If you're printing, 300 ppi is the standard. If your image is 72 ppi and you scale it to print size without changing the resolution, it will print blurry because the pixels are too far apart. You can't fix this by raising the resolution number alone — you have to actually have enough pixels in the file.

For screen display (websites, email, presentations), 72 ppi is fine. For print, 300 ppi is the minimum. If you have a 72 ppi image and need to print it at a large size, you'll have to accept either a smaller print or a softer image — there's no way around it without a higher-resolution original.

Using Canvas Size to add space without resizing the image

Canvas Size changes the workspace, not the image itself. Go to Image > Canvas Size. The dialog shows the current width and height, with a small preview showing where your image sits on the new canvas.

Type new dimensions. The preview shows a small rectangle (your image) on a larger grid (the new canvas). Click on the rectangle to move it — click the center square to center the image, or click a corner to anchor it to that corner. The empty space fills with your background color.

This is useful for adding a border, creating space for text below a photo, or preparing an image for a specific layout. It doesn't change the image quality because the pixels stay exactly as they are.

Avoiding the most common mistakes

The chain link icon is the biggest one. If it's broken (unlinked), changing width doesn't change height, and you'll stretch the image into a weird shape. Check that it's connected before you type a new dimension.

Scaling up is the second mistake. Photoshop can enlarge an image, but it always looks softer because the software is inventing pixels. If you need a larger image, go back to the original file or ask for a higher-resolution version. Don't try to fix a small image by scaling it up in Photoshop.

Not saving a copy is the third. Scaling is permanent. If you scale down and then realize you needed the original size, you can't get those pixels back. Before you resize, go to File > Save As and save a copy with a different name. Keep the original untouched.

Forgetting to check resolution before printing is the fourth. A 72 ppi image scaled to 8x10 inches will print blurry. Check the resolution number in the Scale Image dialog before you click OK.

When to use Image Size instead of Scale Image

Image Size is an older command that does the same thing as Scale Image — it's in Image > Image Size. Most people use Scale Image now because it's clearer, but Image Size still works. The dialog looks slightly different, but the chain link, resolution field, and resampling options are in the same places.

You don't need to learn both. Pick one and stick with it. Scale Image is the newer, more straightforward choice.

Resampling options and when they matter

At the bottom of the Scale Image dialog, there's a dropdown labeled "Resample". It's usually set to "Automatic" or "Bicubic Sharper" (for scaling down) or "Bicubic Smoother" (for scaling up). These control how Photoshop invents or discards pixels.

For most work, the default is fine. If you're scaling down a photo for web, Bicubic Sharper keeps edges a little crisper. If you're scaling up (which you should avoid), Bicubic Smoother makes the blur less obvious. You don't need to change this unless the result looks noticeably soft or jagged.

If you're scaling a graphic with hard edges (like a logo or text), try "Nearest Neighbor" instead — it keeps edges sharp but can look blocky. For photographs, stick with Bicubic.

Frequently Asked Questions

Can I undo a resize after I save the file?

No. Once you save, the resize is permanent. The undo history in Photoshop disappears when you close the file. This is why saving a copy before you resize matters — keep the original untouched so you can always go back to it.

What's the difference between scaling and cropping?

Scaling changes the size of the entire image. Cropping removes the edges and keeps only the center part. Use the Crop Tool (keyboard shortcut C) to remove unwanted edges, then scale if you need to change the overall size.

Why does my image look blurry after I scale it up?

Photoshop invented pixels that weren't in the original. Scaling up always softens the image because the software has to guess what those new pixels should look like. The only fix is to start with a higher-resolution original or accept the softer result.

Do I need to change the resolution if I'm only resizing for email?

No. For email and screen display, 72 ppi is standard and fine. Just scale the image to the width you want (usually 600 pixels or less for email), and leave the resolution alone.

What happens if I scale down, then scale back up to the original size?

You won't get the original quality back. Scaling down throws away pixels permanently. Scaling back up invents new ones, but they're not the same as the ones you lost. Always keep the original file and scale from that if you need multiple sizes.