How to Change the DPI of an Image on Your Computer

What DPI means and why you might need to change it

DPI stands for dots per inch — it measures how many pixels print in each inch of physical paper. A 72 DPI image looks fine on a screen but prints blurry. A 300 DPI image prints sharp but takes up more storage space. You change DPI when you're preparing an image for print, shrinking a file for email, or converting between formats.

DPI and pixel dimensions are separate things. You can have a 1000×1000 pixel image at 72 DPI or at 300 DPI — the pixel count stays the same, but the printed size changes. Most images from cameras and phones start at 72 DPI. Most print shops ask for 300 DPI.

The method you use depends on what software you have and whether you want to change the DPI without changing how the image looks on screen. Some tools change DPI without resizing the image. Others resize it automatically to keep the printed dimensions the same.

Key Takeaways

DPI is a print setting that does not affect how an image looks on your screen, only how it prints on paper.
Most free tools (Preview on Mac, Paint on Windows, or online converters) can change DPI in under a minute.
Changing DPI to a higher number does not improve image quality — it only tells the printer how to space the pixels it already has.
Print shops typically require 300 DPI; screen use typically requires 72 DPI.
If you need to enlarge an image and keep it sharp, you need to increase the pixel dimensions, not just the DPI.

Using Preview on Mac

Open the image in Preview (the default image viewer on macOS). Go to Tools in the menu bar, then select Adjust Size. A window will open showing the current resolution in pixels and the current DPI.

Look for the field labeled Resolution or DPI. Type in the new DPI value — 300 for print, 72 for screen. If a chain link icon appears between width, height, and resolution, make sure it is locked (connected) if you want the printed size to stay the same. If it is unlocked, the pixel dimensions will stay the same and only the DPI will change. Click OK, then save the file using File > Export.

Using Paint on Windows

Open the image in Paint (search for "Paint" in the Windows start menu). Go to File, then Properties. You will see the current image dimensions in pixels, but Paint does not show DPI in this window.

To change DPI in Paint, you need to use a different approach: go to Image (if available in your version) or use an online tool instead. Paint's built-in options are limited for DPI adjustment. For a Windows computer, consider using free software like IrfanView or GIMP, both of which have straightforward DPI controls.

Using GIMP (free, Windows and Mac)

Open the 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 for Resolution with a dropdown showing the current DPI.

Change the number to your target DPI. A chain link icon between width, height, and resolution controls whether the pixel dimensions change. If the chain is linked, changing DPI will resize the image to keep the printed dimensions the same. If the chain is broken, only the DPI changes and pixels stay the same. After you set the DPI, click Scale, then go to File > Export As to save the file.

Using online DPI converters

If you do not want to install software, several free websites let you upload an image and change its DPI. Search for "online DPI converter" or "change image DPI." Upload your image, enter the new DPI value, and download the result. These tools work on any computer with a web browser.

Online converters are fast for one-off changes but may compress the image slightly or have file size limits (usually 10 to 50 MB). They do not store your image after you download it, though you should check the site's privacy policy if you are working with sensitive photos.

Understanding what happens when you change DPI

When you change DPI without resizing the image, the pixel count stays the same but the printed size changes. A 1000×1000 pixel image at 72 DPI prints at roughly 14×14 inches. The same image at 300 DPI prints at roughly 3×3 inches. The image quality does not improve — you are just telling the printer to pack the same pixels into a smaller space.

If you need a larger printed image and want it to stay sharp, you cannot just raise the DPI. You need to increase the pixel dimensions first using an image editor's resize or scale tool. Adding pixels is called upsampling, and it does not create detail that was not there — it fills in gaps by guessing. For best results, start with the highest-resolution image you have.

Saving your image after changing DPI

After you change the DPI, save the file in a format that preserves the DPI information. JPEG, PNG, and TIFF all store DPI data. When you save, most software will ask whether you want to overwrite the original or save as a new file — choose Save As or Export As to keep the original.

If you are sending the image to a print shop, ask them what format they prefer. Many accept JPEG or TIFF. Some may ask for PDF. When you upload to a print service (like a photo printing website), the service usually shows you the DPI of the file you uploaded and warns you if it is below 300 DPI.

Frequently Asked Questions

Does changing DPI make an image look better on my screen?

No. DPI only affects printing. Your screen displays images based on pixel dimensions and screen resolution, not the DPI embedded in the file. An image at 72 DPI and the same image at 300 DPI look identical on a monitor.

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

Increasing DPI alone will not make an image print larger — it will make it print smaller. To print larger, you need to increase the pixel dimensions using a resize tool. However, enlarging a low-resolution image will make it blurry because you are adding pixels that do not contain real detail.

What DPI should I use for different purposes?

Use 72 DPI for images that will only appear on screens (websites, email, social media). Use 300 DPI for printing photos, documents, or anything going to a professional print shop. Some specialty printing (like fine art or large format) may ask for 600 DPI or higher.

Will changing DPI make my file larger or smaller?

Changing DPI alone does not change file size much — the pixel count is what matters. If you increase DPI and the software resizes the image to keep the printed size the same, the file will shrink because there are fewer pixels. If you increase DPI without resizing, file size barely changes.

What if my image is already too small for printing?

If your image is small (like 500×500 pixels) and you need to print it large, increasing DPI will not help. You would need to enlarge the pixel dimensions, which requires upsampling software. The result will not be as sharp as a native high-resolution image, but it may be acceptable depending on the print size and viewing distance.

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.