Instagram New Long Post Size 2025 Post Size. We provide tips for when (and why) to use each image size in our instagram image size guide here. Instagram's 2025 grid layout update changed post sizes from square to rectangular, making them longer.

Whether you’re sharing a square, portrait, or landscape image, nailing the dimensions is essential to making. For portrait posts, 1080 x 1350 pixels with a 4:5 aspect ratio provides the best.