How to Crop an Image Online

1:1 is right for Instagram square posts. 16:9 works for YouTube thumbnails, presentations, and most widescreen banners. 4:3 fits standard photo prints and many display ads. 9:16 is for Stories and Reels.

Choosing the correct ratio before uploading saves time — your image will fit the platform without unexpected cropping or letterboxing.

Some outputs need exact pixel sizes: Open Graph images are 1200×630, Twitter cards are 800×418, and many e-commerce thumbnails are 800×800.

Enter the pixel dimensions directly instead of relying on a drag-resize tool, especially when a pixel-perfect export is required for ads or structured data.