Shared foundations first: both phones run on dual-SIM LTE, support Wi-Fi 5, use USB Type-C, include a fingerprint scanner, and offer expandable storage — so the everyday connectivity checklist is largely identical. The most striking divergence, however, is in cellular throughput. The Oppo A5x lists a download speed of 2900 Mbits/s and upload of 900 Mbits/s, dwarfing the Vivo Y04's 300 Mbits/s down and 100 Mbits/s up. This reflects a significantly more capable LTE modem in the A5x, which translates to faster file downloads, smoother video streaming on strong networks, and more responsive cloud-based tasks.
Bluetooth tells a slightly different story. The Y04 carries Bluetooth 5.2 against the A5x's 5.0, which in theory offers marginally better connection stability and efficiency — though the practical difference for typical audio or peripheral use is minimal. The A5x compensates with two extras the Y04 lacks: a compass, which enhances navigation accuracy in mapping apps, and an infrared sensor, which allows the phone to function as a universal TV and appliance remote — a genuinely handy feature that adds utility well beyond connectivity.
Weighing it all up, the Oppo A5x holds a clear overall advantage in this category. Its dramatically faster modem, compass, and infrared blaster collectively outweigh the Y04's minor Bluetooth version bump, making it the more feature-complete device for connectivity and everyday utility.