The Reddit Post Image size (1200×628px)
A 1200x628 image at roughly 1.91:1 is a reliable size for Reddit because it doubles as both a clean in-feed post image and a link preview thumbnail. When you share a link, Reddit and most platforms pull the 1.91:1 open-graph style card, so an image at these dimensions displays fully in the feed without Reddit awkwardly cropping the top and bottom the way it does with tall or square images.
Reddit's card feed rewards images that read at a glance while people scroll fast through a busy subreddit. At 1200x628 your image is wide enough to look substantial in the feed and detailed enough to stay sharp when a user taps in, without being so large that it slows loading. The landscape shape also suits the memes, screenshots, charts, and article previews that make up so much of Reddit content, where a horizontal layout fits naturally.
Because Reddit shows a smaller thumbnail in compact and card views before the full image opens, keep the focal point and any text centered and large enough to survive that shrink. Avoid packing critical detail into the corners, which can be cropped in certain thumbnail treatments. Everything here resizes 100% in your browser with no upload and for free, so your images stay private on your device. Reddit periodically changes its feed layout and how it crops previews across old and new interfaces, so verify the current behavior before relying on an exact crop.