In terms of physical footprint, the Honor 400 5G is the more compact and lighter device. It weighs 184 g versus the Vivo S30's 192 g, is marginally thinner at 7.3 mm compared to 7.5 mm, and has a smaller overall volume (85.23 cm³ vs 89.39 cm³). The width is nearly identical, but the Vivo S30 is notably taller at 160.2 mm versus 156.5 mm. In practice, these differences mean the Honor 400 will feel slightly more manageable during one-handed use and in a pocket, while the Vivo S30's taller frame is largely a consequence of its larger display area.
Where the two phones diverge most meaningfully is water protection. The Vivo S30 carries an IP67 rating, which means it can withstand full submersion in up to 1 meter of fresh water for 30 minutes. The Honor 400 5G is rated IP65, offering protection against low-pressure water jets but not submersion. For most everyday scenarios — rain, splashes, or accidental spills — both phones are well-protected. However, for users who swim, work near water, or simply want stronger peace of mind, the Vivo S30's IP67 is a tangible, real-world advantage.
Overall, neither phone has a rugged build and neither folds, so they are evenly matched on those fronts. The decision in this category comes down to priorities: the Honor 400 5G has an edge in ergonomics and portability due to its lighter, more compact form, while the Vivo S30 holds a clear advantage in water resistance, making it the stronger choice for users who prioritize durability against liquid exposure.