How to Upscale a Photo for Printing Without Losing Quality

You found the perfect photo, ordered a print, and it came back blurry or pixelated. The cause is almost always the same: the image didn't have enough pixels for the print size. Here's how to check before you print, and how to fix a photo that's too small.

How many pixels does a print need?

Print quality depends on how many pixels end up in each inch of paper, called PPI (pixels per inch). For prints you hold in your hand and look at closely, 300 PPI is the standard for sharp results. Posters and canvases that are viewed from a few steps away still look good at around 150 PPI.

To work out the pixels you need, multiply the print size in inches by the PPI:

• 4 × 6 in photo at 300 PPI: 1200 × 1800 pixels
• 5 × 7 in photo at 300 PPI: 1500 × 2100 pixels
• 8 × 10 in photo at 300 PPI: 2400 × 3000 pixels
• A4 (8.3 × 11.7 in) at 300 PPI: about 2480 × 3508 pixels
• 18 × 24 in poster at 150 PPI: 2700 × 3600 pixels

To check your photo's size, open its file info: Get Info on a Mac, Properties → Details on Windows, or the info panel in your phone's photo app.

Why changing the DPI setting doesn't help

Many editors and print shops let you change a photo's "DPI" or "resolution" setting to 300. This only changes a label stored in the file. It tells the printer how large to print the pixels, but it does not add any pixels. A 600 × 800 photo labeled 300 DPI simply prints at 2 × 2.7 inches; stretch it to 8 × 10 and it looks just as soft as before.

To print bigger and sharp, you need more real pixels. That's what upscaling does.

Regular resizing vs. AI upscaling

If you enlarge a photo in a regular editor, the software fills the new pixels by blending the old ones. The image gets bigger, but edges turn soft and fine detail disappears.

An AI upscaler predicts the missing detail instead. It has learned from many pairs of low- and high-resolution images what edges, skin, fabric and text should look like when enlarged, so the result holds up much better on paper.

Step by step: upscale a photo for printing

1. Find the largest original you have. A photo straight from your phone or camera beats a copy downloaded from social media or a chat app, which is usually resized and compressed.
2. Crop first. Crop to the final print shape before upscaling, so all the pixels go to the part you'll actually print.
3. Choose the scale. Divide the pixels you need by the pixels you have. If you need about 2x, choose 2x. If you need more, choose 4x. For example, an 800 × 600 photo becomes 3200 × 2400 at 4x, enough for an 8 × 10 in print at 300 PPI on the long side.
4. Turn on face enhancement for portraits. Faces are what people look at first in a print.
5. Check the result at 100% zoom before you order. Look at eyes, text and edges.

In QualityEnhancer, the largest result is 4096 pixels on the longest side. That's enough for about a 13.6-inch long side at 300 PPI, or around 27 inches at 150 PPI for posters.

When the photo is too small even for 4x

AI upscaling can't create unlimited detail. A 200-pixel thumbnail will improve noticeably at 4x, but it won't look like a professional photo at poster size. If your photo is very small, choose a smaller print size or a print style viewed from further away, such as a canvas on a wall.

Ready to print?

Upload your photo to the photo quality enhancer, choose 2x or 4x, and download a print-ready PNG. Each photo costs 1 credit at either size, and new accounts get free credits to try it first.