How to Change Photo DPI in Common Programs

What DPI means and why you might need to change it

DPI stands for dots per inch — it tells a printer how many dots of ink to place in each inch of your photo. A higher DPI means more detail and sharper prints; a lower DPI means a smaller file and faster uploads. When you take a photo with your phone or camera, it already has a DPI baked in, usually 72 DPI for screens or 300 DPI for printing. You change it when you need to print larger than the photo naturally allows, or when a website or service asks for a specific DPI.

The confusion happens because DPI only matters for print. If you are uploading to Instagram, email, or a website, DPI does not affect how the image looks on screen — only the pixel dimensions do. But if you are sending a photo to a print shop, a yearbook, or a magazine, they will ask for 300 DPI. If you are printing at home on a standard inkjet, 150 DPI is usually enough.

The good news: changing DPI is not hard, and you do not need expensive software. Every common photo editor — including free ones — can do it in under a minute.

Key Takeaways

DPI only matters when you print; it has no effect on how photos look on screens or websites.
Most print shops ask for 300 DPI, while home printing usually works fine at 150 DPI.
You can change DPI in Windows Photos, Mac Preview, Photoshop, GIMP, or online tools — all in one or two clicks.
Changing DPI does not change the actual photo quality; it only changes how the printer interprets the file.
If your photo is too small in pixels, raising DPI will not make it print sharper — you need more pixels, not a higher DPI number.

How to change DPI in Windows Photos

Windows Photos is built into every Windows computer and handles DPI changes without opening a separate editor. Open the photo in Photos, click the three dots in the top right, and select Edit. Then click the three dots again and choose Crop & rotate. At the bottom of the screen, you will see a menu that says Aspect ratio — click that dropdown and select More options. This opens a panel where you can set the DPI directly.

Type your target DPI (usually 300 for print shops, 150 for home printing) into the DPI field. Click explore, then Save a copy at the top right. Windows will save a new version of your photo with the DPI you set, leaving the original untouched. The file size may change slightly, but the image itself looks identical on your screen.

How to change DPI in Mac Preview

Mac Preview is equally straightforward. Open your photo in Preview, go to the menu bar and click Tools, then select Adjust Size. A window appears showing the current resolution. At the bottom, you will see a field labeled Resolution with a number and the word pixels/inch — that is the DPI.

Change that number to your target DPI. Make sure the chain-link icon between width and height is locked (connected) so the proportions stay the same. Click OK, then go to File and choose Export. Save the file with a new name so you keep the original. Preview will save the updated DPI information into the file.

How to change DPI in Photoshop or GIMP

If you already use Photoshop, the process is nearly identical to Preview. Go to Image in the menu bar, select Image Size, and look for the Resolution field. Change the number to your target DPI and click OK. Then save the file as a new copy using File > Export As.

GIMP, the free Photoshop alternative, works the same way. Open your photo, click Image in the menu, select Scale Image, and change the resolution field at the bottom. The chain-link icon keeps proportions locked. Click Scale, then go to File > Export As to save it with the new DPI.

Using online tools if you do not have photo software

If you do not want to install anything, several free websites let you upload a photo and change its DPI without downloading software. Sites like Pixlr, Canva, and Photopea all have DPI adjustment tools. Upload your photo, find the image size or resolution settings (usually under Image or Document settings), change the DPI number, and read the result.

The trade-off with online tools is that you are uploading your photo to someone else's server. If the photo is private or sensitive, use one of the desktop programs above instead — they keep everything on your computer. Online tools are fastest when you only need to change DPI once and do not want to learn new software.

Understanding what happens when you raise DPI on a small photo

A common mistake: thinking that raising DPI will make a small photo print larger or sharper. It will not. DPI is only instructions to the printer; it does not add detail that was not there. If your photo is 1000 pixels wide and you raise the DPI from 72 to 300, the photo will print smaller (because the printer is packing more dots into each inch), but it will not look sharper.

What matters for print quality is the number of pixels. A 1000-pixel-wide photo at 300 DPI will print about 3.3 inches wide. If you need it to print 8 inches wide at 300 DPI, you need a photo that is at least 2400 pixels wide. Raising DPI on a small photo is like turning up the volume on a quiet recording — you are just making the existing information louder, not adding new information.

Checking the DPI of a photo you already have

Before you change anything, you might want to see what DPI your photo currently has. On Windows, right-click the photo file, select Properties, then click the Details tab. Scroll down to find Image section, and look for Horizontal Resolution or DPI. On Mac, right-click the photo, select Get Info, and look for Resolution in the More Info section.

If you cannot find it in the file properties, open the photo in Preview (Mac) or Photos (Windows) and follow the steps above to open the image size dialog. The current DPI will be displayed there. This is useful before you send a photo to a print shop — you can check whether you need to change it or whether it already meets their requirements.

Frequently Asked Questions

Does changing DPI make my photo file bigger?

Not significantly. The pixel dimensions stay the same, so the file size barely changes. DPI is metadata — information about how to print the file, not the image data itself. A photo that is 2000 pixels wide will be roughly the same file size at 72 DPI or 300 DPI.

What DPI should I use if I am not sure?

Use 300 DPI. It is the standard for professional printing and works for almost everything — print shops, yearbooks, magazines, and photo labs all expect 300 DPI. If you are printing at home on an inkjet, 150 DPI is fine and will save ink. Never go below 72 DPI for print.

Can I change DPI on a JPEG, PNG, or other file format?

Yes. DPI works the same way regardless of file format. JPEG, PNG, TIFF, and BMP all store DPI information. When you change DPI in any photo editor and save the file, the new DPI is written into the file, no matter what format you use.

If I raise DPI, will my photo look better on my computer screen?

No. Screens do not use DPI — they use pixels. Changing DPI has zero effect on how a photo looks on your monitor, phone, or tablet. DPI only matters when you print. If a photo looks blurry on your screen, raising DPI will not fix it; you need to increase the pixel dimensions instead.

What if the print shop says my DPI is too low?

You cannot fix it by raising DPI alone. If your photo is 1500 pixels wide and the print shop says it needs 300 DPI, raising the DPI will only make it print smaller. You need a larger original photo — at least 2400 pixels wide for a standard 8-inch print at 300 DPI. Ask the print shop what pixel dimensions they need, not just what DPI.

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.