How to Check the Resolution of an Image

What image resolution means and why it matters

Image resolution is the number of pixels packed into your image, usually shown as width × height (for example, 1920 × 1080). It determines how much detail the image holds and how large you can print or display it without it looking blurry or pixelated. A photo that looks sharp on your phone might fall apart when you try to print it at 8 × 10 inches, or a graphic you made for social media might be too small to use on a poster.

Resolution matters differently depending on what you're making. A web image needs far fewer pixels than a print image. An image for Instagram Stories (1080 × 1920 pixels) is completely different from one for a printed brochure (which might need 3000 × 2000 pixels or larger). Knowing your image's actual resolution before you start editing or uploading saves you from discovering halfway through that you don't have enough pixels to work with.

Key Takeaways

On Windows, right-click the image file, select Properties, and look for the dimensions listed under the Details tab.
On Mac, select the image in Finder, press Command+I, and the resolution appears in the General or More Info section.
Online tools like Pixlr, Canva, or your browser's built-in inspector show resolution without downloading software.
Image editing programs like Photoshop, GIMP, or Pixlr display resolution in the Image menu or file properties.
Resolution is different from file size — a 5 MB image might be 800 × 600 pixels or 4000 × 3000 pixels depending on compression.

Checking resolution on Windows

Right-click the image file and select Properties from the menu. A window opens showing file information. Click the Details tab at the top. Scroll down until you see Image as a category header. Under it, you'll find Dimensions listed as two numbers separated by an × symbol — that's your resolution.

If the Details tab doesn't show image information, the file might be corrupted or saved in an unusual format. Try opening the image in Windows Photos (the default image viewer) instead. Right-click the image, select Properties, and look for resolution information in the Details section. If that doesn't work, move to the online or software methods below.

Checking resolution on Mac

Select the image file in Finder and press Command+I (or right-click and select Get Info). A window opens showing file details. Look for a section labeled Image or More Info. The resolution appears as Dimensions or Pixel Dimensions, shown as width × height.

If you're using Preview (Mac's built-in image viewer), open the image and go to Tools in the menu bar, then select Inspector. The resolution shows in the inspector panel on the right side. This method works for almost any image format — JPEG, PNG, GIF, TIFF, and others.

Using online tools to check resolution

If you don't want to install software or dig through file properties, upload your image to a free online tool. Pixlr (pixlr.com) lets you open any image and displays the resolution at the top of the editor window. Canva (canva.com) shows dimensions when you upload an image. ImageResizer (imageresizer.com) is built specifically for checking resolution — just drag and drop your image and it displays the pixel dimensions when ready.

These tools work in any web browser on any device. You don't need to create an account or read anything. The downside is that you're uploading your image to someone else's server, so avoid this method if the image contains sensitive information or if you're working with large files that take a long time to upload.

Checking resolution in image editing software

Photoshop displays resolution in the Image menu. Click Image at the top, then select Image Size. A dialog box shows the pixel dimensions (width and height) and also the print resolution in DPI (dots per inch). GIMP, the free alternative, works the same way: go to Image > Scale Image.

Pixlr (the free online editor) shows resolution at the top of the window as soon as you open an image. Paint.NET (a lightweight Windows tool) displays it in Image > Canvas Size. If you already have an image open in editing software, this is usually the fastest way to check — you don't need to close the program or open a new tool.

Understanding DPI versus pixel dimensions

Resolution has two parts: pixel dimensions (how many pixels wide and tall) and DPI (dots per inch, which affects print size). An image might be 3000 × 2000 pixels at 300 DPI for print, or the same 3000 × 2000 pixels at 72 DPI for web. The pixel count is identical, but the print size is different.

For web use — social media, websites, email — DPI doesn't matter. Only pixel dimensions matter. For print, you need both: enough pixels and a high enough DPI (usually 300 DPI for photos, 600 DPI for text-heavy documents). When you check resolution on Windows or Mac using the file properties method, you usually see only pixel dimensions, not DPI. To see DPI, open the image in editing software like Photoshop or GIMP.

What to do if your image resolution is too low

If you discover your image is 800 × 600 pixels but you need 2000 × 1500 pixels, you have limited options. You cannot add pixels that aren't there — enlarging a small image makes it blurry. Your choices are: find a higher-resolution version of the same image, shoot or create a new image at the size you need, or scale down your project to fit the resolution you have.

Some tools claim to upscale images using artificial intelligence, but they create new pixels by guessing, which produces soft or artificial-looking results. They work better for enlarging by 20 to 50 percent than for doubling the size. If you're designing for print and your image is too small, it's usually worth the time to find or create a better version rather than trying to enlarge a low-resolution file.

Frequently Asked Questions

Is resolution the same as file size?

No. A 5 MB image file could be 800 × 600 pixels or 4000 × 3000 pixels depending on how much it's compressed. File size depends on resolution, color depth, and compression method. Always check pixel dimensions, not file size, to know if an image has enough detail.

What resolution do I need for social media?

Instagram feed posts work best at 1080 × 1350 pixels. Stories are 1080 × 1920. Facebook cover photos are 820 × 312. Twitter headers are 1500 × 500. These are minimums — larger images get resized down, but smaller ones look pixelated. Check the platform's help center for current specs, as they change occasionally.

What resolution do I need for printing?

For a 4 × 6 inch print at 300 DPI, you need 1200 × 1800 pixels. For an 8 × 10 inch print, you need 2400 × 3000 pixels. The formula is: desired print width in inches × 300 DPI = required pixel width. If your image is smaller, the print will be blurry or pixelated.

Can I check resolution on my phone?

Yes. On iPhone, open the image in Photos, tap Edit, then tap the three dots menu and select Info. On Android, open the image in Google Photos, tap the three dots, and select Details. Both show pixel dimensions. You can also email the image to yourself and check it on a computer using the methods above.

Why does my image look different on screen than in the file properties?

Your screen is displaying the image at a certain zoom level. The file properties show the actual pixel dimensions, which don't change. A 1920 × 1080 image looks small if you zoom out to 50 percent and large if you zoom to 200 percent, but the resolution stays the same.

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.