Instagram Reels vs Carousels: Which Actually Performs Better?
Reels get more reach. Carousels get more engagement. An analysis of Buffer's 4M+ post study reveals why format superiority depends entirely on content objectives.
Buffer's analysis of more than 4 million Instagram posts found that Reels received 36% more reach than carousels and 125% more reach than single-image posts, while carousels generated 12% more engagement than Reels and 114% more engagement than single-image posts.
Core Rank Kiwi Takeaway: There is no single universal “best” Instagram format. Format performance depends on objective: Reels drive top-of-funnel non-follower discovery, whereas Carousels cultivate depth, saves, and follower retention.
Analyzing 4 million Instagram posts reveals a clear structural trade-off rather than a single “best” format: Reels deliver 36% higher reach for non-follower discovery, while Carousels achieve 12% higher engagement for community depth and saves. Single static images lag on both metrics.
What We Wanted to Know
Rather than asking generic questions about which post type is “better,” our analysis focused on three practical operational questions:
- How large is the actual distribution gap between short-form video and multi-image posts across a multi-year sample?
- Does higher video reach translate into proportionally higher comments, saves, and likes?
- How should creators structure their publishing mix based on whether they need brand awareness versus audience trust?
The Dataset & Methodology
Buffer's research team analyzed over four million posts published via their social media management platform. The dataset tracked unique account reach (impressions served to distinct users) and engagement rates (likes, comments, shares, and saves relative to reach) across three primary format types: Reels (short-form vertical video), Carousels (swipeable swipe-posts with 2–10 images or video cards), and Single Images.
The Published Benchmark Data
The table below reflects the exact comparative figures reported by Buffer, alongside Rank Kiwi's derived relative multipliers:
| Content Format | Reach vs Carousels | Reach vs Single Images | Engagement vs Reels | Engagement vs Single Images |
|---|---|---|---|---|
| Instagram Reels | +36% | +125% | Baseline (0%) | +91% |
| Carousels (Multi-slide) | Baseline (0%) | +65% | +12% | +114% |
| Single Images | -56% vs Reels | Baseline (0%) | -48% vs Reels | Baseline (0%) |
Visual Comparison: Reach Advantage vs Engagement Advantage
Relative benchmark comparison of Reels and Carousels against baseline formats
Source: Buffer analysis of 4M+ Instagram posts (Jan 2022 – Oct 2024). Calculations and visual presentation produced by Rank Kiwi Research.
Rank Kiwi Derived Calculations
By standardizing the published percentage differences into relative baseline multipliers, we can model the exact efficiency advantage of each format:
Rank Kiwi Analysis: Three Key Insights
Finding 1: Reels Operate as Non-Follower Discovery Vehicles
The 36% reach advantage of Reels over carousels (and 125% over static photos) stems directly from Instagram's distribution architecture. Reels are served primarily through the dedicated Reels tab and algorithmic Explore feeds to people who do not yet follow the creator. For audience expansion, Reels provide the highest top-of-funnel exposure.
Finding 2: Carousels Maximize Dwell Time and High-Intent Actions
Despite lower raw impressions, carousels outperformed Reels on engagement by 12% and single photos by 114%. Swiping through multiple slides increases active session dwell time. Furthermore, users frequently bookmark (save) informational carousels for later reference. For educating audiences and fostering relationships, carousels hold a structural advantage.
Finding 3: The Single Image Format Faces Severe Structural Headwinds
Single photos suffered a 56% penalty in reach relative to Reels and less than half the engagement of carousels. Unless an image possesses extraordinary contextual novelty or celebrity endorsement, static single-image posts rarely achieve algorithmic escape velocity in current feeds.
What This Means vs What This Does NOT Mean
- Pick formats based on strategy: Reels for reach, carousels for community engagement.
- Evaluate posts by their specific objective, not a single blended metric.
- Benchmark a creator's Reels against their own Reels baseline, and carousels against carousel baselines.
- It does not mean Reels “always beat” carousels.
- It does not prove the Instagram algorithm penalizes images out of malice.
- It does not guarantee that converting an image into a video will automatically double its views.
Methodological Limitations
Responsible research requires explicit disclosure of sample boundaries:
- Buffer User Base Bias: The 4M+ post dataset is derived from accounts using Buffer, which leans toward active creators, small businesses, and agencies rather than casual personal profiles.
- Cross-Niche Aggregation: These figures are global averages across industries. In visual niches like photography or fashion, single images often retain much higher relative engagement.
- Algorithmic Evolution: The study window (Jan 2022 – Oct 2024) saw major Instagram updates. Meta adjusted carousel distribution in late 2024 to re-serve carousels on second slides if unviewed.