Carousels get 6x the save rate of reels. Reels get 64x the shares.
The "should I post carousels or reels?" question assumes they compete for the same job. They don't. They serve completely different functions in how people engage with your content, and the data makes it obvious.
Data from 4,484 Instagram posts (3,162 video, 798 carousel, 524 image) across 13 creators. All metrics via Instagram's official API. Save rates and share rates computed as pool-level ratios (total saves / total reach), which avoids the distortion you get from averaging individual post rates.
The numbers
I ran the format comparison across every post in our pool that had both saves and reach data. The split is dramatic.
| Format | Posts | Save rate | Share rate | Avg saves | Avg shares | Avg reach |
|---|---|---|---|---|---|---|
| Carousels | 798 | 12.91% | 0.15% | 920 | 11 | 7,122 |
| Reels | 3,162 | 1.94% | 1.14% | 1,199 | 706 | 61,923 |
| Images | 524 | 25.95% | 0.07% | 351 | 1 | 1,354 |
Carousels have a 12.91% save rate. Reels have a 1.94% save rate. If you stopped reading here, you'd think carousels win.
But look at the share column. Reels average 706 shares per post. Carousels average 11. Images average 1.
That's a 64x difference in shares. And shares are what drive algorithmic distribution.
Saves and shares are different behaviors
When someone saves a carousel, they're bookmarking it. "I want to come back to this." It's a personal, private action. The kind of post you save is a listicle, a how-to breakdown, a framework you want to reference later.
When someone shares a reel, they're distributing it. "I want someone else to see this." It's a social action. The kind of post you share is entertaining, surprising, or says something you want to co-sign.
The data confirms this split cleanly. Carousels are reference content (high save rate, almost no shares). Reels are distribution content (lower save rate, massive shares).
Why reels dominate reach
Reels average 61,923 reach per post. Carousels average 7,122. Images average 1,354.
The mechanism is shares. Instagram's algorithm distributes content that gets shared. Every share puts your reel in front of a new audience who can then save, share, and follow. It compounds.
Carousels don't get this distribution because people save them privately. The algorithm sees saves as a positive signal, but it doesn't spread the content the way shares do.
What this actually means for your content strategy
Post both. They serve different purposes.
Reels grow your audience.They're the top of funnel. The share mechanic means each reel is a chance to reach people who've never heard of you. If you want more followers, reels are the lever.
Carousels deepen your audience.They're the retention play. A carousel that gets saved is a post that keeps delivering value after the initial impression. The person who saved your "5 pricing frameworks" carousel is the person most likely to buy from you.
The mistake I see most often: creators who only post carousels wonder why their reach is flat. They have great save rates but zero shares, so Instagram doesn't distribute their content beyond existing followers.
One caveat on save rates
Image and carousel save rates look inflated (25.95% and 12.91%) compared to reels (1.94%). Part of this is real: carousels genuinely get saved more per impression. But part of it is measurement asymmetry. Saves accumulate over the lifetime of a post, while reach measures unique viewers during the initial distribution window. Older posts can have saves that exceed their reach. This effect is strongest for images and carousels, which tend to be "evergreen reference" content that people keep discovering and saving months later.
Rate comparisons are most reliable within the same format (comparing one reel's save rate to another reel's). Cross-format comparisons are directionally useful but not precise.
See your own save and share rates
Connect your Instagram. Dally shows you the metrics that predict performance. Free.
Get started