How to Change the DPI of an Image

What DPI means and why you might need to change it

DPI (dots per inch) is a measure of how many pixels fit into one inch of a printed image. A higher DPI means more detail and a sharper print; a lower DPI means a smaller file and faster uploads. You change DPI when you need to print something at a specific size, send a file to a printer with particular requirements, or reduce file size for email or web use.

The confusion usually comes from mixing up two different things: the actual pixel dimensions of your image (how many pixels wide and tall it is) and the DPI setting (how densely those pixels are packed when printed). Changing DPI does not add or remove pixels — it only tells the printer how to space them out. If you need a sharper print, you may need to enlarge the image itself first, which does add pixels.

Most images on screens are 72 DPI by default. Print shops typically ask for 300 DPI. Web images usually stay at 72 DPI. Phone photos are often 72 DPI but contain millions of pixels, so they can print large and sharp even at 300 DPI.

Key Takeaways

DPI is a print setting that tells the printer how densely to pack pixels; changing it does not add or remove pixels from your image.
Most free and paid image editors (GIMP, Photoshop, Preview on Mac, Paint on Windows) can change DPI in seconds without altering how the image looks on screen.
Print shops usually need 300 DPI; web images work fine at 72 DPI; changing DPI is separate from resizing the actual image.
If an image is too small to print sharp at 300 DPI, you need to enlarge the pixels themselves, not just change the DPI number.

How to change DPI in GIMP (free, all platforms)

Open your image in GIMP. Go to Image in the menu bar, then select Scale Image. At the bottom of the window, you will see a field labeled Resolution with a number and the letters "ppi" (pixels per inch — this is the same as DPI). Change that number to what you need: 300 for print, 72 for web.

The chain link icon next to the width and height fields controls whether the image dimensions change when you adjust DPI. If the chain is linked, changing DPI will shrink or enlarge the printed size but keep the pixel count the same. If the chain is broken, you can change DPI without changing the printed dimensions. Click Scale when you are done, then go to File > Export As to save the file.

How to change DPI in Photoshop

Open your image and go to Image in the menu bar, then Image Size. You will see the current resolution listed in the middle section. Make sure the chain link icon between width and height is linked (this keeps your image from stretching). Change the resolution number to 300 for print or 72 for web, then click OK.

If you see a warning that your image is too small to print at 300 DPI, you have two choices: accept the lower DPI for a smaller print, or go back and use Image > Image Size again, this time checking the Resample box and enlarging the pixel dimensions before changing DPI. Resampling adds pixels and can soften the image slightly, so only do it if you have no other option.

How to change DPI on Mac using Preview

Open your image in Preview (the default image viewer on Mac). Go to Tools in the menu bar, then Adjust Size. You will see a field for Resolution with a number and "ppi" next to it. Change this to 300 for print or 72 for web. Make sure the chain link icon is linked so the image does not stretch.

Click OK when you are done. Then go to File > Export and choose your format (JPEG, PNG, or TIFF). The DPI change is now embedded in the file and will be recognized by print shops and other software.

How to change DPI on Windows using Paint

Open your image in Paint (the built-in Windows image editor). Go to Image in the menu, then look for Properties or Resize. Windows Paint has limited DPI controls compared to other editors. If you do not see a DPI field, you may need to use a free alternative like GIMP instead.

For a more straightforward approach on Windows, read GIMP (free) or use an online tool. Many free online DPI changers exist and require no installation — you upload the image, set the DPI, and read the result. These work well for straightforward DPI changes but may compress your image slightly.

Understanding DPI versus image size

A common mistake is thinking that changing DPI will make an image look sharper or larger. It will not. Changing DPI only changes the print instruction; the actual pixels stay the same. If you have a 1000-pixel-wide image at 72 DPI, it will print about 14 inches wide. At 300 DPI, the same image prints about 3 inches wide — smaller, not sharper.

To print larger and sharper, you need more pixels. A phone photo with 4000 pixels wide can print sharp at 300 DPI at about 13 inches wide. A small screenshot with 800 pixels wide will print blurry at 300 DPI no matter what you do. If you need to enlarge an image, use Image > Scale Image in GIMP or Image > Image Size with Resample turned on in Photoshop, but understand that this softens the image slightly.

What DPI to use for different purposes

For printing at home or a local print shop, use 300 DPI. This is the standard for photos and documents that will be held in hand. For large format printing (posters, banners), 150 DPI is often acceptable because viewers stand farther away. For web images, email, and screen display, 72 DPI is standard and keeps file size small.

If you are sending an image to a professional print shop, ask them what DPI they need before you change anything. Some shops accept 240 DPI; others require 300. Some can work with 72 DPI if the image has enough pixels. The DPI number only matters if you have enough pixels to support it — a tiny image at 300 DPI is still tiny.

Frequently Asked Questions

Will changing DPI make my image look different on my computer screen?

No. DPI is a print setting only. Your image will look identical on screen no matter what DPI you set. The DPI number only affects how the image prints or how other software interprets it for printing.

Can I change DPI without losing quality?

Yes, as long as you are only changing the DPI number itself and not resizing the pixels. Changing DPI from 72 to 300 keeps all your pixels intact. If you need to enlarge the image to support a higher DPI, that process (called resampling) can soften the image slightly.

What if my print shop says my image is too low resolution?

This usually means you do not have enough pixels, not that the DPI is wrong. Count your pixels: if your image is 1000 pixels wide and you need to print 10 inches wide, you need at least 3000 pixels (300 DPI × 10 inches). If you have fewer pixels, the print will be blurry. You can enlarge the image in your editor, but this softens it slightly.

Is there a difference between DPI and PPI?

In practice, no. DPI stands for dots per inch (for printers), and PPI stands for pixels per inch (for digital images). Most software uses them interchangeably. Your image editor will show one or the other, but they mean the same thing.

Can I change DPI in online image editors?

Yes. Many free online tools let you upload an image, set the DPI, and read the result. These work well for straightforward DPI changes. Search for "online DPI changer" or "online image resolution tool." Be aware that some may compress your image slightly during the process.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.