Oppo F31 5G VS Vivo Y400 5G

Both the Oppo F31 5G and the Vivo Y400 5G share an IP68 waterproof rating, meaning both are certified for submersion in fresh water. However, they are not equal here: the Vivo Y400 5G holds a clear edge with a rated depth of 2 m, compared to 1.5 m for the Oppo F31 5G. In practice this means the Y400 5G offers a larger safety margin if accidentally dropped in a pool or sink, while the F31 5G still provides solid everyday splash and submersion protection. Neither phone has a rugged build or a foldable form factor.

In terms of physical dimensions, the two devices are very close but not identical. The Oppo F31 5G is the more compact and notably lighter handset at 185 g versus 197 g for the Vivo Y400 5G — a 12 g difference that is perceptible during prolonged one-handed use or all-day carry. The Vivo is also taller at 162.3 mm compared to 158.2 mm, which may matter for users with smaller hands or those who prefer a more pocketable profile. Thickness is effectively a tie at 8 mm vs 7.9 mm.

Overall, the two phones trade blows in design: the Oppo F31 5G wins on ergonomics with its lighter weight and shorter frame, making it the more comfortable daily carry. The Vivo Y400 5G counters with superior waterproofing depth, giving it a practical durability edge for users who frequently expose their phone to water. Which advantage matters more depends squarely on the user's priorities — comfort in hand versus confidence near water.

At their core, both phones deliver an OLED/AMOLED panel with a 120Hz refresh rate and near-identical 1080p sharpness — around 395–397 ppi — so everyday clarity and scrolling smoothness are virtually the same on either device. The Vivo Y400 5G is slightly larger at 6.67″ versus 6.57″, but the difference is minor and unlikely to be a deciding factor on its own.

Where the two screens genuinely diverge is brightness and content support. The Vivo Y400 5G's 1200 nits typical brightness is double the Oppo F31 5G's 600 nits, which has meaningful real-world consequences: in direct sunlight or bright outdoor environments, the Y400 5G's display will remain far more legible. Compounding this, the Y400 5G also supports HDR10, enabling richer contrast and a wider tonal range when streaming compatible content on platforms like Netflix or YouTube. The F31 5G supports none of the major HDR standards.

The Oppo F31 5G counters with branded damage-resistant glass — a protection layer absent on the Vivo — which adds a degree of scratch and drop resilience to the screen. Still, on display performance alone, the Vivo Y400 5G holds a clear advantage: its dramatically higher brightness and HDR10 support make it the stronger choice for outdoor use and premium media consumption, advantages the F31 5G's screen protection cannot fully offset.

On the surface, these two phones look nearly identical in performance: both pack 8GB of RAM, 256GB of storage, an 8-core big.LITTLE CPU layout, and near-matching clock speeds. But the silicon underneath tells a more nuanced story. The Vivo Y400 5G runs on a Snapdragon 4 Gen 2 built on a 4nm process, while the Oppo F31 5G uses a Dimensity 6300 on a 6nm node. A smaller fabrication process generally means the chip runs cooler and more efficiently under sustained load — relevant for gaming sessions or long video calls where thermal throttling can quietly reduce performance over time.

The memory architecture gap is the most tangible differentiator. The Y400 5G uses DDR5 RAM running at 3200 MHz, whereas the F31 5G relies on DDR4 at 2133 MHz — roughly 50% less memory bandwidth. Faster RAM translates to snappier app switching, quicker load times, and smoother multitasking, especially as apps grow more memory-hungry. The Y400 5G also supports up to 16GB maximum memory versus 12GB on the F31 5G, giving it more headroom for future software demands.

The Vivo Y400 5G holds a clear performance edge in this group. While day-to-day tasks may feel comparable to most users, the more modern 4nm chip, faster DDR5 memory, and higher memory ceiling collectively give the Y400 5G a meaningful advantage in sustained performance, efficiency, and longevity — factors that compound over the lifespan of the device.

The rear camera systems on these two phones are, for all practical purposes, identical: both feature a 50 MP + 2 MP dual-lens setup with matching apertures, phase-detection autofocus, HDR mode, slow-motion, and a full suite of manual controls. Neither offers optical image stabilization or optical zoom. For everyday photography, users can expect a very similar rear camera experience from both devices.

The real split comes down to a direct trade-off between selfies and video. The Vivo Y400 5G steps ahead for portrait and selfie use with a 32 MP front camera, compared to just 16 MP on the Oppo F31 5G — double the resolution, which means sharper detail and more cropping flexibility in self-portraits. The Oppo, however, counters decisively in video: it can record at 4K (2160p) at 30fps, while the Vivo Y400 5G tops out at 1080p at 30fps. For users who shoot video content, vlogs, or simply want to archive memories in the highest quality, that 4K capability is a meaningful and tangible advantage.

There is no single winner here — the right choice depends entirely on shooting priorities. The Vivo Y400 5G is the stronger pick for selfie-focused users, while the Oppo F31 5G holds a clear edge for anyone who values video quality. Given that 4K video is increasingly the standard for shareable and future-proof content, users who film frequently may lean toward the F31 5G on this criterion alone.

This is a rare case of complete parity: every single operating system specification listed is identical between the Oppo F31 5G and the Vivo Y400 5G. Both ship with Android 15 and offer the same feature set across privacy controls, customization, productivity, and accessibility — including dark mode, dynamic theming, split-screen multitasking, Picture-in-Picture, on-device machine learning, and offline voice recognition.

Notably, both phones share the same limitations too: neither receives direct OS updates from Google, neither blocks cross-site tracking, and neither supports Wi-Fi password sharing or focus modes. The absence of direct OS updates means both devices depend on their respective manufacturers — Oppo and Vivo — to push Android updates, which can affect how quickly security patches and new features reach users.

With no differentiating data point anywhere in this category, the operating system group is an absolute tie. A buyer's decision here will rest entirely on the other specification groups rather than anything software-related.

Battery is where the Oppo F31 5G makes its most compelling statement in this comparison. Its 7000 mAh cell is a full 1000 mAh larger than the Vivo Y400 5G's 6000 mAh pack — a 17% capacity advantage that, all else being equal, translates directly into longer time between charges. For heavy users, commuters, or anyone regularly away from a power outlet, that extra headroom is genuinely meaningful and could mean the difference between reaching the end of a long day comfortably or not.

The Vivo Y400 5G partially closes the gap with slightly faster charging at 90W versus the F31 5G's 80W. In practice, the 10W difference will shave a few minutes off a full charge cycle, but it is a modest offset against a significantly smaller battery. Both phones lack wireless charging, so all recharging depends on a wired connection regardless.

For this group, the Oppo F31 5G holds the clear edge. A larger battery provides a more sustained real-world benefit than a marginally faster charger, and the F31 5G's 7000 mAh capacity positions it as the stronger choice for users who prioritize endurance over top-up speed.

Both phones share the same baseline audio setup — stereo speakers, no 3.5mm headphone jack, and no FM radio — so wired headphone users will need an adapter or Bluetooth on either device. For speaker listening, the experience is nominally equivalent based on the provided specs.

Where the two diverge significantly is wireless audio quality. The Oppo F31 5G supports aptX, aptX HD, and LDAC — three high-resolution Bluetooth audio codecs that dramatically reduce compression artifacts when streaming to compatible wireless headphones or speakers. LDAC in particular, developed by Sony, can transmit up to three times the data of standard Bluetooth audio, making it the gold standard for wireless hi-fi listening. The Vivo Y400 5G supports none of these codecs, meaning it is limited to standard Bluetooth audio compression regardless of how premium the headphones connected to it are.

The Oppo F31 5G wins this category outright. For users who invest in quality wireless headphones or care about audio fidelity on the go, the F31 5G's codec support is a tangible, real-world advantage that the Vivo Y400 5G simply cannot match based on the available data.

Much of the connectivity foundation is shared between these two devices: both support 5G, dual SIM, NFC, USB Type-C (USB 2.0), Wi-Fi 5, GPS with Galileo, and a fingerprint scanner. For most users, this common ground covers all the essential bases. However, a few pointed differences are worth examining closely.

The Oppo F31 5G pulls ahead in wireless performance with Bluetooth 5.4 — a newer version than the Vivo Y400 5G's Bluetooth 5.0 — offering improved connection stability and more efficient pairing. It also posts a notably higher peak download speed of 3300 Mbps versus 2500 Mbps on the Y400 5G, a 32% gap that reflects stronger cellular modem capability, relevant in areas with dense 5G coverage. The Vivo Y400 5G counters with one exclusive feature: a gyroscope, which the F31 5G lacks. A gyroscope enables more accurate motion sensing, impacting augmented reality apps, immersive gaming, and navigation precision — use cases that matter to a specific but notable segment of users.

On balance, the Oppo F31 5G edges ahead in this category, with its faster download speeds and newer Bluetooth version outweighing the Y400 5G's gyroscope advantage for the majority of users. That said, anyone who relies on AR applications or motion-sensitive gaming should weigh the Vivo's gyroscope support as a meaningful differentiator.

This is a compact spec group with limited data points, but there is one meaningful distinction. Both phones include a video light and neither features sapphire glass or an e-paper display. The sole differentiator is that the Vivo Y400 5G has a curved display, while the Oppo F31 5G uses a flat panel.

A curved screen is primarily an aesthetic and ergonomic choice: the edges of the display gently wrap around the sides of the device, creating a sleeker, more premium visual impression and a smoother feel when swiping in from the edges. The trade-off is that curved displays can be slightly more prone to accidental edge touches and are often harder to fit with screen protectors.

Based solely on the data provided here, this category offers no clear performance winner — it comes down to personal preference. Users who value a more refined, modern look may favor the Vivo Y400 5G's curved display, while those who prefer a no-compromise flat screen for case and protector compatibility may find the Oppo F31 5G's design more practical.