How to Resize an Image on iPhone (Built-In, Free)

To resize an image on iPhone, open it in Photos, tap Edit, then use the crop tool to change dimensions or aspect ratio (square, 16:9, etc.). For exact pixel dimensions, use a free app like Image Size. Not on iPhone? See how to resize an image on Windows and Mac.

Method 1: Photos app (crop to a ratio)

1. Open the photo in Photos → tap Edit.
2. Tap the crop icon (bottom toolbar).
3. Tap the aspect-ratio button (top-right) to pick Original, Square, 16:9, 4:3, etc.
4. Drag the corners to adjust, then tap Done.

This crops rather than resizing the full image — great for social posts and aspect-ratio changes.

Method 2: Change the actual pixel size

The Photos app doesn’t resize to exact pixels. Use a free app:

1. Install Image Size (free, iOS).
2. Open the app → load your photo.
3. Enter the width or height in pixels (the other auto-adjusts).
4. Tap Save — it exports a resized copy to Photos.

Method 3: Reduce file size instead

If your goal is a smaller file (for email or upload), use the Mail app’s automatic resize: when attaching a photo, Mail offers Small / Medium / Large / Actual Size.

FAQ

How do I resize an image on iPhone for free?

Use the Photos crop tool for aspect ratios, or the free Image Size app for exact pixel dimensions.

Does the Photos app resize to specific pixels?

No — it crops by ratio. For exact pixel sizing, use an app like Image Size.

How do I make an image smaller to send?

Attach it in Mail and choose Small or Medium, or compress it with an app — see how to reduce image file size.

Can I resize without cropping?

Yes — the Image Size app scales the whole image down without cutting anything off.