How to Crop an Image Online Free — Custom Size and Ratio

Cropping removes unwanted areas from the edges of an image. It is different from resizing — cropping changes what is in the frame, while resizing changes the size of the entire image. Here is how to crop precisely to any dimension.

Cropping vs Resizing: What Is the Difference?

• Cropping: Cuts away the edges of the image. The remaining content keeps its original pixel density. Use cropping to change composition or remove backgrounds.
• Resizing: Scales the entire image up or down. All pixels are kept but the dimensions change. Use resizing to change file size or meet dimension requirements.

How to Crop to a Specific Aspect Ratio

Aspect ratio cropping is useful for social media where platforms require specific proportions (1:1 for Instagram squares, 9:16 for Stories, 16:9 for YouTube thumbnails). Using our Image Resizer: 1. Upload your image 2. Set the output dimensions to match your target aspect ratio (e.g., 1080×1080 for 1:1) 3. The resizer fits the content within your chosen dimensions

Common Crop Sizes

After Cropping: Compress the Result

• Cropping to exact pixel dimensions often results in a larger file than needed. After cropping, compress your image:
• Compress to 100KB for web images
• Compress to 50KB for email or online forms
• Compress to 20KB for passport or visa applications
• The combination of crop → resize → compress produces the smallest file at the right dimensions.

Tips for Better Crops

• Apply the rule of thirds: place the main subject at one of the four intersection points
• For portrait photos (ID, passport, profile): centre the face and leave space above the head
• For landscape photos: keep the horizon in the upper or lower third, not the middle
• Save a copy before cropping — cropping is destructive and removes pixels permanently