The basic steps for resizing a photo

You can change a photo's size using built-in tools on Windows, Mac, iPhone, or Android without buying software. The method depends on what device you're using and whether you want to make the image smaller for email or storage, or larger for printing.

On Windows, right-click the photo file, select "Open with," and choose Photos or Paint. On Mac, open the photo in Preview, click Tools, then Adjust Size. On iPhone, use the Photos app and tap Edit, then pinch to zoom. On Android, open Google Photos, tap the image, select Edit, and use the crop tool to resize.

Each method takes about one minute once you know where to look. The photo stays in the same format (JPG, PNG, etc.) unless you choose to save it differently.

Key Takeaways

  • Windows and Mac computers have free photo editors built in — Photos on Windows and Preview on Mac — that let you resize without installing anything.
  • Resizing smaller (compressing) is safe and makes files faster to email or upload; resizing larger can make the image blurry.
  • Your phone's native photo app (Photos on iPhone, Google Photos on Android) includes basic resize and crop tools.
  • When you resize, always save the result as a new file so you keep the original photo unchanged.

Resizing photos on Windows

Open File Explorer and find the photo you want to resize. Right-click it and select "Open with," then choose the Photos app (the default on Windows 10 and later). Once the photo opens, look for the three-dot menu in the top right corner and tap "Edit." You'll see a crop tool and a rotate option; the crop tool lets you change the frame size.

If you want to change the actual pixel dimensions (width and height), use Paint instead. Right-click the photo, select "Open with," and choose Paint. Go to Image in the menu bar, then select Resize and Skew. Enter the new width and height in pixels, or use the percentage field to shrink or enlarge by a set amount. Click OK, then go to File and Save As to save the resized version with a new name.

Paint saves in BMP format by default, so if you want to keep it as JPG or PNG, click the dropdown next to "Save as type" and choose your format before saving.

Resizing photos on Mac

Open Finder, locate your photo, and double-click it to open Preview (the default image viewer on Mac). Once the photo is open, click Tools in the menu bar at the top of the screen. Select Adjust Size from the dropdown menu.

A window will appear showing the current width, height, and resolution in pixels. Change any of these numbers to resize. If the chain-link icon next to width and height is locked, the proportions stay the same when you change one dimension. Unlock it if you want to stretch or squash the image. Click OK when you're done, then go to File and Export As to save the resized photo with a new name and format if needed.

Resizing photos on iPhone

Open the Photos app and select the photo you want to resize. Tap Edit in the top right corner. At the bottom of the screen, you'll see a series of icons; tap the crop icon (it looks like two overlapping right angles). Use your fingers to pinch and drag the corners to change the frame size and shape.

When you're done, tap Done. The photo is now cropped to the new size. If you want to change the pixel dimensions rather than just crop, you'll need a third-party app from the App Store, as the built-in Photos app only crops. Tap Done to save your changes, and the original photo remains unchanged in your library.

Resizing photos on Android

Open Google Photos (or your phone's default gallery app) and select the photo. Tap the pencil icon to enter edit mode. Look for the crop icon at the bottom of the screen and tap it. Drag the corners and edges to resize the frame, or tap the rotate icon to change the orientation.

When you're satisfied, tap Save. Google Photos saves the edited version as a copy, so your original stays in your library. If you want to change pixel dimensions rather than just crop, download a free app like Pixlr or Snapseed from the Google Play Store, which offer more detailed resize options.

Understanding file size versus image dimensions

Two different things happen when you resize a photo: the dimensions (width and height in pixels) and the file size (how many megabytes it takes up on disk). Reducing dimensions almost always reduces file size, which is why resizing is useful for email or uploading.

A photo that is 4000 pixels wide might be 8 megabytes. Resizing it to 2000 pixels wide usually brings it down to 2 megabytes or less. Making a photo larger (from 2000 to 4000 pixels) doesn't add detail — it just stretches the existing pixels and makes the image look blurry. This is why photos from older phones or cameras don't enlarge well.

When you save a resized photo, the app may also compress it (reduce quality slightly to save space). Most built-in tools do this automatically and the difference is invisible to the human eye.

Choosing the right size for your purpose

For email, aim for 1200 to 1600 pixels on the longest side and under 2 megabytes total. For social media (Facebook, Instagram, Twitter), 1080 pixels wide is standard. For printing a 4x6 photo, 1200 pixels wide is enough; for an 8x10 print, use 2400 pixels wide. For a website, 800 to 1200 pixels wide is typical.

If you're not sure what size you need, start by making the photo smaller than you think you'll need. You can always resize again. It's much easier to enlarge a photo slightly than to shrink one that's already too big for your purpose.

Frequently Asked Questions

Can I make a blurry photo sharp by resizing it larger?

No. Resizing larger only stretches the pixels that already exist; it doesn't add detail. If a photo is blurry, it will stay blurry when enlarged. Some apps claim to "upscale" or "enhance" photos, but they use guessing algorithms that rarely produce good results.

What format should I save the resized photo in?

JPG is best for photos because it compresses well and works everywhere. PNG is better if you need a transparent background. Avoid BMP and TIFF for everyday use — they create huge files. Most phones and computers default to JPG, which is fine for most purposes.

Will resizing a photo delete the original?

No, as long as you use "Save As" or "Export As" instead of just "Save." This creates a new file with the new size and leaves the original untouched. Always do this so you have a backup of the full-size version.

How do I resize multiple photos at once?

On Windows, use the Photos app's batch edit feature or download free software like IrfanView. On Mac, Preview doesn't batch resize, but you can use Automator (built into Mac) to resize folders of photos. On phones, you'll need a third-party app like Batch Photo Resizer (Android) or Resize Master (iPhone).

Why does my resized photo look worse than the original?

This usually means you enlarged it (made it bigger), which stretches pixels and causes blurriness. If you shrunk it and it looks worse, the app may have over-compressed it. Try resizing again and choosing a higher quality setting if the app offers one.