The most fundamental design difference here is form factor. The DJI Osmo Action 6 follows a classic action camera silhouette — wide and short at 72.8 × 47.2 × 33.1 mm — while the Insta360 X4 Air is tall and narrow at 46 × 113.8 × 37 mm, resembling a slim remote control. This isn't just aesthetic: the X4 Air's elongated shape is optimized for 360° lens placement, whereas the Action 6's compact block form makes it easier to mount low-profile on helmets or handlebars. The Action 6 also wins on overall bulk, with a volume of 113.7 cm³ versus 193.7 cm³ for the X4 Air, and comes in lighter at 149 g compared to 165 g — a meaningful difference when mounting on gimbals or drones.
The Action 6 holds a clear edge in two practical design specs. First, it includes a secondary screen (front-facing display) that the X4 Air lacks entirely — critical for vloggers or solo shooters who need to frame themselves. Second, it ships with 50 GB of internal storage, while the X4 Air offers none, making the X4 Air fully dependent on a memory card from the outset. The Action 6 also edges out on environmental resilience: it is waterproof to 20 m versus 15 m, and handles higher ambient heat up to 45 °C versus 40 °C, while both share the same cold-weather floor of -20 °C.
Overall, the DJI Osmo Action 6 has a clear design advantage for users who prioritize compactness, self-shooting convenience, and built-in storage headroom. The Insta360 X4 Air's taller profile is a deliberate trade-off suited to its 360° capture purpose, but on purely physical and usability design criteria, the Action 6 is the more versatile and self-sufficient package.