Choose social media image dimensions for the specific placement, not only the platform name. A feed post, full-screen story, profile image and link preview can have different crop and upload rules. Check the current requirements in the destination editor, then export a copy that preserves the subject and readable text within that placement.
Record requirements before exporting
Write down the accepted formats, aspect ratio, minimum dimensions, maximum byte size and any crop preview shown by the platform. Organic posts, ads and link previews are different publishing flows and may not share the same requirements. This article does not provide a supposedly permanent table of platform dimensions because those interfaces and rules change.
Use separate compositions for different shapes
Illustrative example: a wide event banner cannot become a tall story simply by reducing its width. Create a placement-specific crop or canvas in an editor, move text away from interface overlays and keep faces or product details away from likely crop edges. Resizing proportionally does not add padding or create a new composition.
Choose a format the uploader accepts
JPEG is a practical candidate for photographic content; PNG can suit graphics needing transparency or crisp detail when accepted. Browser support for WebP or AVIF does not guarantee a social publishing interface accepts them. Consult the actual uploader and preserve a high-quality source for later versions.
Check after the platform processes it
Preview the upload in the intended placement, then inspect a published or permitted test version on the devices that matter. The service may resize, recompress or crop the upload, so the local file is not necessarily what viewers receive. Keep essential text readable after that processing and use the platform alternative-text feature where available. No export setting guarantees identical pixels after publication.