Drop an image, get it at exactly 1200×630 pixels (1.91:1) — the de-facto Open Graph link-preview size. Center cover-cropped, compressed, nothing uploaded; it all runs in your browser.
1200×630 (1.91:1) is the size link previews want: it's what Facebook recommends for og:image, and the same file renders cleanly on LinkedIn, Slack, Discord, WhatsApp, Telegram and most chat apps that unfurl links. One honest footnote: the Open Graph protocol itself doesn't mandate any size — 1200×630 is the de-facto standard because it fills Facebook's preview without cropping, and everyone else followed. Facebook will display images down to 600×315 and rejects anything under 200×200.
Every time someone pastes your link, some bot downloads this image. A lean file unfurls faster and never trips a fetcher's size limit, which is why this page presets a 300 KB budget — at 1200×630 that's high JPEG quality with room to spare. If your preview is mostly flat graphics and text rather than a photo, WebP from the Format selector keeps edges crisper at the same bytes (most unfurlers handle WebP now, but JPEG is the zero-risk choice).
Some surfaces crop the preview to a square or shave the edges, so keep titles and faces near the center. Sources that aren't 1.91:1 get center cover-cropped here — PixFit shows you both ratios when that happens. If you're making the X (Twitter) large-card variant, it tolerates the same 1200×630 fine; the profile header is a different shape entirely: 1500×500.