Why image conversion changes the aspect ratio

You convert a photo to a different format, then it looks stretched, squashed, or cropped. The change can come from the conversion, but it can also happen when an app resizes the image or handles its orientation differently.

Use the Image Converter to convert a copy, then compare the original and converted image. Checking their pixel dimensions helps you tell whether the shape actually changed or only looks different in a particular viewer.

Compare the original and converted image

1. Open the Image Converter and convert a copy of the original to the format you need. The tool supports formats including JPG, PNG, WEBP, GIF, BMP, ICO, and TIFF.
2. Open both images in the same viewer and compare the full image, not just a thumbnail or preview. Check whether the edges are missing, the subject looks stretched, or the picture is simply rotated.
3. Check the pixel width and height of both files. On Windows 11, right-click an image in File Explorer, choose Properties, then open Details. On macOS, open the image in Preview and choose Tools › Show Inspector.
4. Compare the width-to-height ratios. For example, an image that is 4,000 by 3,000 pixels has a 4:3 ratio. If the converted file is 1,600 by 1,200 pixels, it is smaller but still 4:3.

Convert one image first, especially if you are preparing a batch of files. The Image Converter can process up to 50 images at once, but checking a single output helps catch a problem before you convert the rest.

What the result means

The dimensions changed, but the ratio stayed the same

The image was resized proportionally. For example, reducing a 4:3 picture from 4,000 by 3,000 pixels to 2,000 by 1,500 pixels changes its resolution, not its shape. This is normal and should not make people or objects look distorted.

The ratio changed and parts of the image are missing

The picture was probably cropped. A crop removes pixels along one or more edges, often to fit a preset shape such as a square or widescreen frame. A 4:3 photo changed to 16:9 cannot show the same full frame unless the image is padded with empty space or another background.

The ratio changed and the whole image looks stretched

The width and height were likely changed by different amounts. For instance, changing a 4:3 image to 1,600 by 900 pixels forces it into a 16:9 shape. The image may still contain every edge, but circles and faces can look wider or taller.

The dimensions appear swapped or the image looks rotated

Some cameras and phones store a rotation instruction in the image metadata instead of turning all the pixels. One app may use that instruction, while another may ignore it or apply the rotation when saving. The width and height can appear reversed even though the picture's intended shape is unchanged.

The numbers match, but the preview looks different

The viewer may be cropping its thumbnail, fitting the image into a frame, or displaying it at a different zoom. Compare the files at the same zoom and inspect the full image. If the pixel dimensions and visible edges match, the conversion probably did not change the aspect ratio.

How to fix a changed aspect ratio

1. Convert the untouched original. Start with the source file rather than a version that has already been cropped, stretched, or repeatedly saved. Keep the original as a backup.
2. Check for a crop or resize before export. If the app you are using offers crop or resize options, choose the original proportions or keep the aspect ratio locked. Avoid selecting a target width and height with a different ratio unless you want to crop or add space.
3. Compare the actual dimensions. Use File Explorer's Properties › Details on Windows 11 or Preview's Tools › Show Inspector on macOS. If the ratio differs, convert the source again and avoid any separate edit or export step that changes its dimensions.
4. Check the crop in your phone's photo editor. On an iPhone, open the photo in Photos, tap Edit, then check Crop before saving. In Google Photos on Android, open the image, tap Edit, then check the crop controls. Menu names can vary by phone and app version.
5. Try a different viewer. Open the original and output in another image viewer if only one app shows the problem. This can reveal a thumbnail or orientation display issue rather than a changed image.
6. Convert a fresh copy and check it again. If the output still has a different ratio, save the original and converted file separately and compare their dimensions. This helps identify whether the change happens during conversion or in a later editing or sharing step.

Why orientation metadata can confuse the comparison

Phones often record an orientation instruction so a viewer knows which way to display a photo. The stored pixel grid might be 4,032 by 3,024, while the instruction says to rotate the picture for portrait viewing. A converter or editor may apply that rotation directly to the pixels and save the result as 3,024 by 4,032.

Those numbers have different width-to-height ratios, but after the rotation both files can show the same portrait-shaped scene. Compare how the complete image is displayed as well as the raw dimensions. If the output is sideways, or its edges are cut off, use an image editor that can rotate or crop the photo as intended, then convert that corrected copy.

Changing a format should preserve the image's proportions when no crop or non-proportional resize is applied. Keep the original file until you have checked the converted version in the app where you plan to use it.