TL;DR
- Instagram Reels still wins on raw reach and creator culture.
- Facebook Reels wins on monetization for many niches, especially if your audience is 30+.
When Facebook Reels makes more sense
- Local businesses with an older customer base
- Lifestyle, parenting, finance, and home content
- Anyone enrolled in the Facebook Reels Play bonus or ads on reels
A simple cross-post workflow
- Shoot once, vertical 9:16, with no on-screen Instagram watermark.
- Post natively to Instagram first thing in the morning.
- Post the same reel to Facebook in the evening so it's not "duplicate detected" in the same hour.
- Run a small free views boost on whichever side is colder.