Open Graph image size guide: the right dimensions for Facebook, Twitter, LinkedIn, and Discord
The de facto standard Open Graph image size is 1200x630 pixels, a 1.91:1 aspect ratio. This works across Facebook, Twitter (summary_large_image card), LinkedIn, Discord, Slack, WhatsApp, and iMessage. If you generate only one OG image size, make it 1200x630. It's the closest thing to a universal social preview format.
How this is calculated
Each platform crops or scales differently. Twitter's summary_large_image card shows the full 1.91:1 image. Its summary card (default) shows a small 1:1 square thumbnail, which you get by omitting twitter:card or setting it to summary. Facebook crops to 1.91:1 on desktop and 1:1 on mobile feeds. LinkedIn displays at 1.91:1 on desktop. Discord shows the full image in embeds. Slack unfurls at roughly 360x190. The safe zone for text and logos is the center 600x315 of a 1200x630 image, which survives cropping on all platforms.
Verdict
Generate one 1200x630 PNG or JPEG for og:image. Keep critical content in the center 600x315 safe zone. Add a 200x200 twitter:image square if you want a dedicated Twitter summary card thumbnail. Validate with each platform's debugger before shipping.