Why pictures get stretched
A photo straight from a phone is usually 4:3 (4000×3000 pixels, say). Instagram’s portrait post is 4:5 (1080×1350). The shapes are different, so to fill the frame the picture must either be cropped, padded, or stretched. Stretching is what happens when you simply type 1080 and 1350 into a resizer with the aspect lock off. The result looks subtly wrong: round faces become oval.
Option A: fill and crop (cover)
Scale the photo until it covers the whole frame, then trim the overflow. This keeps proportions but removes some of the picture.
Worked example: 4000×3000 photo to 1080×1350.
- Scale factor to cover: the larger of 1080/4000 = 0.27 and 1350/3000 = 0.45, so 0.45.
- Scaled size: 1800×1350.
- Trim the extra width: 1800 − 1080 = 720 pixels, so 360 pixels from each side if centred.
The result keeps 60% of the width of the scaled picture. If the subject is off-centre, use the Image Cropper first with a 4:5 ratio, and place the box where you want it. Then resize the result to 1080×1350.
Option B: fit and pad (contain)
Scale the photo until it fits inside the frame, then add bars. Nothing is cropped. Use it for product shots, posters, and group photos where every edge matters.
Worked example: same 4000×3000 photo to a 1080×1080 square.
- Scale factor to fit: the smaller of 1080/4000 = 0.27 and 1080/3000 = 0.36, so 0.27.
- Scaled size: 1080×810.
- Padding: 270 pixels in total top and bottom, so 135 each.
Choose a padding colour that matches your brand or the photo background.
Step by step in the Image Resizer
- Add your photo to the Image Resizer.
- Tap a preset such as “Instagram portrait 1080×1350”. The fit mode switches to Fill and crop.
- Prefer to keep everything? Change “When the shape differs” to Fit inside and pad and pick a colour.
- Press Resize image, download, and repeat for the next platform from the same original.
Plan for the crop before you shoot
If you know the photo will be used in several shapes, leave breathing room around the subject when you take it. A 4:5 portrait crop needs height above and below the subject; a 16:9 thumbnail needs width on the sides.
Safe zones
Even a perfectly sized image can be spoiled by overlays. Stories and Reels place the profile name at the top and the reply bar at the bottom. Video covers show a duration stamp in a corner. Keep text and faces away from these areas.
Resolution and quality
Never enlarge a small image to reach a target size. A 600-pixel picture stretched to 1080 will look soft. Start from the original. After resizing, compress modestly: platforms recompress uploads, so heavy compression before upload can double the quality loss. A moderate JPG quality of about 85–90 is a reasonable choice. Our cheat sheet lists the common sizes.
Try it: Image Resizer
Resize to exact pixels or to a social media preset. Free, private, and it runs in your browser.
Open Image ResizerFrequently asked questions
How do I resize a photo without distorting it?
Keep the aspect ratio locked, or use fill-and-crop or fit-and-pad modes so the picture keeps its proportions.
What is the difference between crop and resize?
Resizing changes the pixel dimensions of the whole picture. Cropping removes part of the picture.
Why does my Instagram photo look blurry?
The image may have been too small and then enlarged, or compressed heavily before upload. Start from a high-resolution original at about 1080 pixels wide.
Should I use PNG or JPG for social media?
JPG is usually best for photographs. PNG can be better for graphics with text.
Can I make several sizes at once?
Make one at a time from the same original. Each takes a few seconds.