Instagram briefly replaces vertical feed with horizontal scrolling for many users, says it was meant to be a small test that “went broader than we anticipated”
The new layout was caused by a bug, according to the company — Instagram has quietly started testing a horizontal feed …
Context & Ripple Effects
The horizontal feed landed just weeks after Instagram began testing new profile layouts that rearrange core elements — part of a late-2018 run of surface-level redesign experiments at the company. The company framed the swipe-based home feed as a deliberately scoped test that a bug pushed far beyond its intended audience.
Seen against what followed, the incident reads as an early data point in a longer arc: by early 2021 Instagram had confirmed work on a TikTok-like "Vertical Stories" feed prototype, and by 2022 it was testing Home, Favorites, and chronological Following feeds users could switch between. The core feed has been under continuous structural renegotiation ever since.
First-order effects
- A large share of Instagram users experienced an unannounced change to the app's most-used surface, forcing the company into damage control and a public walk-back within days of rollout.
Second-order effects
- The misfire raises the cost of every subsequent feed experiment for Instagram: each new layout test now lands on a user base primed to read it as another unwanted change rather than a neutral trial.
Third-order effects
- If the pattern holds, Instagram's core feed converges toward the full-screen, gesture-driven formats it kept prototyping — with tests like this one functioning as involuntary audience-acceptance measurements ahead of permanent shifts.
The trend: Instagram is running an accelerating sequence of feed-format experiments, from profile rearrangements to TikTok-style vertical prototypes, as it rebuilds its core consumption surface around swiping rather than scrolling.