How to Check the DPI of an Image on Your Computer

What DPI means and why it matters for your work

DPI (dots per inch) is a measure of how many pixels are packed into one inch of a printed image. A higher DPI means more detail and sharper output when you print; a lower DPI means the image will look blurry or pixelated on paper. If you're working with photos, graphics, or designs, knowing the DPI tells you whether an image is suitable for printing at the size you need, or whether it's only good for screen display.

The reason this matters: a photo that looks fine on your monitor at 72 DPI will look grainy if you print it at 8 by 10 inches. Most printing services ask for 300 DPI for photographs and 600 DPI for text-heavy documents. Checking DPI before you send work to print or hand it off to someone else saves time and prevents wasted prints.

Key Takeaways

Windows shows DPI in image properties under Details; Mac shows it in Preview or Image Info.
Most online images are 72 DPI (screen resolution) and cannot be enlarged for print without losing quality.
Resizing an image in Photoshop or Preview does not change DPI—you must use the image size or scale dialog to set DPI separately.
Print shops and designers often need 300 DPI for photos and 600 DPI for documents with text.

Checking DPI on Windows

Right-click the image file on your computer and select Properties. Click the Details tab. Scroll down until you see Image section. Look for a line that says Horizontal Resolution and Vertical Resolution—these numbers are your DPI. If both say 72, the image is screen resolution. If they say 300 or higher, it's print-ready at most sizes.

If the Details tab does not show resolution information, the image file may be corrupted or in a format Windows does not recognize fully. Try opening the image in Windows Photos (the built-in app) instead: right-click the image, select Open with, then Photos. Once open, click the three dots menu in the top right and select Properties. The resolution will appear there.

Checking DPI on Mac

Open the image in Preview (the default image viewer). Click Tools in the menu bar, then select Inspector (or press Command + I). A panel will open on the right side showing image details. Look for Resolution—the number shown is your DPI. If you see two numbers separated by an "x", both should be the same for standard images (for example, 300 x 300).

If Preview does not show resolution, try opening the image in Image Capture (search for it in Spotlight). Select the image, then go to File menu and look for image information. You can also right-click the image file in Finder, select Get Info, and scroll to the bottom—some file types display resolution there, though not all.

Using free online tools to check DPI

If you do not want to read software, several websites let you upload an image and see its DPI when ready. Verexif.com and Exif.tools both show DPI along with other image data. Upload your file, and the DPI appears in the results within seconds. These tools work on any computer with a web browser and do not save your image after you close the page.

Be aware that uploading images to a website means sending them over the internet. If the image contains sensitive information or personal photos, use the Windows or Mac method instead. For work files you plan to share anyway, online tools are fast and require no installation.

What to do if your image has low DPI

If your image is 72 DPI and you need 300 DPI, you cannot straightforward change the number in the file properties—that does not add detail that was never captured. However, you have two realistic options: use the image at a smaller printed size (a 72 DPI image can print acceptably at 2 by 3 inches), or use upscaling software to enlarge it.

Upscaling uses artificial intelligence to guess what extra pixels should look like and fill them in. Tools like Topaz Gigapixel AI and Adobe Super Resolution (in Photoshop) do this better than straightforward enlargement, but they are not magic—a tiny 72 DPI photo will never look as sharp as a native high-DPI original. For professional work, the honest answer is usually to reshoot or find a higher-resolution source image.

Changing DPI in Photoshop or Preview

If you have an image at the right size but wrong DPI, you can change the DPI number without resizing the image itself. In Photoshop, go to Image menu, then Image Size. Make sure the chain link icon between width and height is not connected (unlinked). Change the DPI number in the Resolution field to what you need (usually 300 for print). Click OK. The pixel dimensions stay the same, but the DPI metadata changes.

In Preview on Mac, go to Tools menu, then Adjust Size. Uncheck Fit into if it is checked. Change the Resolution number to your target DPI. Click OK. Again, this changes the DPI number without altering the actual pixels, so it only works if your image already has enough pixels for the print size you need.

Understanding DPI versus pixel dimensions

DPI and pixel count are different things, and this confusion trips up many people. An image that is 3000 by 2000 pixels at 72 DPI is the same number of pixels as 3000 by 2000 pixels at 300 DPI—the DPI just tells you how those pixels are spaced when printed. At 72 DPI, those 3000 pixels spread across 41 inches. At 300 DPI, the same 3000 pixels fit into 10 inches. The image does not change; only the intended print size changes.

This is why you cannot fix low DPI by changing the number. If an image is 1000 by 800 pixels at 72 DPI, changing it to 300 DPI does not add pixels—it just says "print this smaller." You still have only 1000 by 800 pixels of actual detail. For print work, what matters is the total pixel count, not the DPI number alone.

Frequently Asked Questions

Can I change DPI without losing quality?

You can change the DPI number in the file without losing quality, but only if you are not resizing the image at the same time. Changing DPI alone just tells the printer how to space the pixels you already have. If you need to enlarge the image to reach a certain print size, you will lose quality unless you use upscaling software.

What DPI do I need for social media or email?

Social media and email only display images on screens, so DPI does not matter. Use 72 DPI or any DPI—screens ignore it and display based on pixel count instead. A 1200 by 800 pixel image will look the same on Instagram whether it is labeled 72 DPI or 300 DPI.

Why does my image show different DPI numbers for horizontal and vertical?

Most images have the same DPI in both directions, but some scanned documents or specialized graphics may differ. If they are close (like 300 x 299), it is usually a rounding difference and does not matter. If they are very different, the image may have been stretched or distorted during editing.

Do I need to check DPI before uploading to a print service?

Yes. Print services often reject files that are too low DPI for the print size you ordered. Checking beforehand prevents rejected orders and wasted time. Most print shops list their DPI requirements on their website—check there first, then verify your image meets it.

Is there a way to see DPI for multiple images at once?

Windows batch tools and command-line programs like ImageMagick can check DPI for many files at once, but they require technical setup. For most people, checking a few key images individually through Properties or Preview is faster than learning those tools.

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.