What DPI means and why you might need to change it

DPI (dots per inch) is the number of pixels packed into one inch of a printed image. A higher DPI means more detail when printed; a lower DPI means a smaller file size and faster uploads. You change DPI when you're preparing an image for a specific use — printing a photo at a lab, uploading to a website, or sending to a printer that has its own requirements.

DPI only matters for print. On a screen, your monitor displays pixels at its own resolution regardless of the image's DPI setting. If you're only sharing images online or viewing them on a computer, changing DPI won't change how they look. But if you're printing, most labs want 300 DPI, while web images can be 72 DPI and still look sharp.

Changing DPI doesn't add or remove detail from your image — it just tells the printer how to space out the pixels you already have. If you have a small, low-resolution photo and you increase its DPI, the printer won't suddenly have more information to work with. You're only changing the math of how those pixels get printed.

Key Takeaways

  • DPI only affects printing; screen display ignores it, so changing DPI for web images makes no practical difference.
  • Most print labs and home printers expect 300 DPI, while web images typically use 72 DPI.
  • Changing DPI in image software like Photoshop, GIMP, or Preview doesn't add detail — it only changes how the printer spaces existing pixels.
  • If you need to enlarge an image before printing, use upscaling software like Topaz Gigapixel or let your printer scale it, rather than increasing DPI alone.
  • Check your printer's manual or your print lab's website for their specific DPI requirement before you change anything.

How to change DPI in Photoshop

Open your image in Photoshop. Go to Image in the menu bar, then select Image Size. A dialog box will open showing your current dimensions and DPI (labeled as "Resolution").

Look for the chain-link icon between the width and height fields. If it's linked (connected), unlinking it lets you change DPI without resizing the image. If you want to keep the same print size and just change DPI, make sure the chain is linked. If you want to change DPI without changing the pixel dimensions, unlink it first.

Type your new DPI number in the Resolution field. For printing, enter 300. For web, enter 72. Click OK. Photoshop will update the metadata but won't change how the image looks on screen — only how a printer will interpret it.

How to change DPI in GIMP (free alternative)

GIMP is free and works on Windows, Mac, and Linux. Open your image, then go to Image in the menu, select Scale Image. At the bottom of the dialog, you'll see "Resolution" with fields for X and Y DPI.

The chain link icon works the same way as Photoshop. If it's linked and you change DPI, GIMP will resize the image to maintain the same print dimensions. If you unlink it, you can change DPI without changing pixel dimensions. Enter your target DPI (300 for print, 72 for web) and click Scale.

GIMP's interface is less polished than Photoshop, but the DPI change itself works identically. The free cost makes it a solid choice if you only need to change DPI occasionally.

How to change DPI on Mac using Preview

Mac's built-in Preview app can change DPI without opening expensive software. Open your image in Preview, then go to Tools in the menu bar and select Adjust Size.

You'll see Resolution listed in dots per inch. Type your new DPI number — 300 for printing, 72 for web. If you want to keep the print size the same, make sure the dimensions adjust automatically. Click OK, then save the file with File > Export to preserve the change.

Preview is simpler than Photoshop or GIMP but has fewer options. It works fine for straightforward DPI changes on images you're not heavily editing.

What to do if you need to enlarge an image before printing

If your image is small and you need to print it larger, straightforward increasing DPI won't help — you'll just be spreading the same pixels further apart, which makes the image look blurry. You need more pixels first.

Your options are upscaling software or letting the printer handle it. Topaz Gigapixel and Adobe Super Resolution (in Photoshop) use AI to guess what new pixels should look like, creating a larger image with acceptable quality. These tools cost money but work better than traditional enlargement.

Alternatively, send your original image to the printer at its native resolution and ask them to enlarge it. Many labs have professional upscaling tools and can tell you the maximum size they can print without quality loss. This is often free and sometimes produces better results than doing it yourself.

Checking your printer or lab's DPI requirement

Before you change anything, find out what DPI your specific printer or lab actually wants. Most home inkjet printers work fine at 240 DPI, while photo labs typically ask for 300 DPI. Some labs accept 200 DPI for smaller prints. The requirement varies.

Check your printer's manual — search the model number plus "DPI requirement" online if you don't have the manual. For print labs, visit their website or call them. They'll tell you exactly what they need. Some labs have a form you fill out when you upload, where you can specify DPI or let them auto-detect it.

Using the right DPI saves you from reprinting. Too low and the print looks pixelated; too high and you're uploading unnecessarily large files.

Saving your image after changing DPI

After you change DPI, save the file in a format your printer or lab accepts. JPEG is standard for photos and works everywhere. PNG preserves quality but creates larger files. TIFF is professional-grade but rarely necessary for home printing.

In Photoshop, use File > Export As to save as JPEG. In GIMP, use File > Export As. In Preview, use File > Export. All three let you choose format and quality settings before saving.

Don't use "Save As" in Photoshop — that saves in Photoshop's native PSD format, which most printers can't read. Always export to JPEG, PNG, or TIFF for printing.

Frequently Asked Questions

Does changing DPI make my image look different on my computer?

No. DPI only affects how a printer interprets the image. Your monitor ignores DPI and displays pixels at its own resolution. You can change DPI from 72 to 300 and the image will look identical on screen.

Can I increase DPI to make a small image print larger?

Increasing DPI alone won't help. It just spreads existing pixels further apart, making the print blurry. You need more pixels first, either from upscaling software or by asking your printer to enlarge it for you.

What DPI should I use for web images?

72 DPI is standard for web, though 96 DPI works too. Websites ignore DPI anyway and display images at screen resolution. The DPI setting doesn't affect how web images look or their file size — only the pixel dimensions matter.

My print lab says they need 300 DPI but my image is only 72 DPI. Can I just change it?

Changing the DPI number won't add detail. If your image is genuinely too small, you'll need to enlarge it using upscaling software or ask the lab if they can print it smaller. Changing DPI alone will result in a blurry print.

Is there a difference between DPI and PPI?

DPI (dots per inch) is technically for printers, while PPI (pixels per inch) is for screens. In practice, most software uses the terms interchangeably, and image software usually labels it as DPI even when working with pixels. The number you enter works the same way either way.