Image Dimensions Checker
Choose an image to detect its exact pixel width and height, simplified aspect ratio, megapixels and file size. The file is read locally in your browser.
How to check photo dimensions
- Choose an image file from your device.
- Read its width and height in pixels, ratio, megapixels and file size.
- Compare those results with the requirements of the website, form, print service or social platform where the image will be used.
Dimensions, ratio and file size are different
Pixel dimensions describe the width and height of the image, such as 1600 × 900. Aspect ratio describes its shape, such as 16:9. File size describes how much storage the file uses. Images can share the same dimensions but have different file sizes because format, detail and compression differ.
How the aspect ratio is detected
The checker divides the width and height by their greatest common divisor. A 1920 × 1080 image becomes 16:9, while 1200 × 1200 becomes 1:1. For unusually sized images, the exact simplified ratio can be less familiar than common formats.
What megapixels tell you
Megapixels are calculated by multiplying width by height and dividing by one million. They describe the number of pixels, not whether the image is sharp, well focused or appropriately compressed.
What to do with the result
If the shape is correct but the image is too large, use Resize Image. If you need another shape, use Crop Image or calculate matching measurements with the Aspect Ratio Calculator. If only the storage size is too high, try Compress Image.
Website image checklist
- Use dimensions close to the largest displayed size.
- Preserve the intended ratio so the picture is not stretched.
- Choose a suitable format and compress after resizing.
- Preview important text and fine details on both desktop and mobile.