Every social platform defines its own grid of container sizes for feed posts, profile pictures, covers, and stories, and uploading an image that doesn't match triggers automatic cropping or recompression that the platform's algorithm chooses, not you. That's why the same photo can look perfectly framed on one platform and awkwardly cropped through a person's face on another.
Common platform dimensions worth knowing
A square Instagram feed post displays best at 1080x1080 pixels, while an Instagram Story or Reel uses a tall 1080x1920 frame. Facebook's shared link image crops to roughly 1200x630, and its cover photo is a wide 820x312 on desktop (with different visible bounds on mobile, which is why text near a Facebook cover's edges often gets cut off). Twitter/X's in-stream image displays around 1200x675, and LinkedIn's shared post image follows a similar 1200x627 landscape ratio. These numbers shift periodically as platforms redesign their interfaces, so treat them as a solid starting point rather than a permanent spec.
Why resizing per platform beats one universal size
Because feed posts, covers, and stories all use different aspect ratios (square, wide landscape, and tall portrait respectively), no single image dimension displays optimally in all three without cropping. The practical fix is keeping one high-resolution master image and exporting platform-specific versions from it, rather than posting the same file everywhere and letting each platform's auto-crop decide what gets cut. Social Media Image Resizer is built specifically for this, offering the common platform presets directly instead of requiring you to look up and enter exact pixel dimensions each time.
If you're preparing a multi-image carousel post specifically for Instagram, Instagram Carousel Splitter slices one wide image into the correctly sized sequential tiles automatically.
Keep text and faces away from the edges
Because platforms sometimes crop covers and thumbnails differently across desktop and mobile, or square-crop a rectangular upload for a grid preview, important content like a face, logo, or text should sit within the center 80% or so of the frame, not right at the edges. Crop Image lets you set an exact aspect ratio and reposition the subject before exporting, which avoids relying on a platform's automatic crop to make a good decision.

