We were shipping one OG image per post. It was 1200 by 630. It was rendered server-side from a Blade template via Puppeteer. We were quite pleased with it.
Then someone in growth pointed out that the same image looked terrible on LinkedIn (cropped weirdly), unremarkable on Twitter (where 1200 by 675 actually shows in full), and tiny on Pinterest (where the feed is a vertical aspect ratio). The fix on paper was simple: make per-platform variants. The fix in practice was a fortnight of getting Puppeteer to behave at eight different viewport sizes.
This article is about the version that came after that. One HTML template, eight platform variants, the API runs the browser. No Chromium to maintain. Worth posting because the fan-out pattern is reusable and quite a lot smaller than what I was carrying before.
Why one shared image is not enough
The reflex is to ship a single 1200 by 630 and let each platform crop. That gets you 70% of the way there and looks fine. The reason teams that care about share traffic go further is that each platform has its own pathology:
