Samsung Galaxy S21 Ultra vs OnePlus 9 Pro: Which One is Better?

OnePlus has introduced two new flagship models housed within a premium case. The OnePlus 9 Pro and Samsung Galaxy S21 Ultra has approximately similar pricing, subject to occasional promos and deals. If you are planning to replace your outdated Android flagship in near future, these two devices could be models to consider.

OnePlus 9 Pro

Design and display

Smartphones with 6.7-inch and 6.8-inch displays can be compact. Premium housings add to the bulkiness and weight of the phone. Using both phones with just one hand can be somewhat uncomfortable. Even so, the OnePlus 9 Pro is a bit easier to handle, because it’s more compact and lighter. The phones look nearly similar. At the top left corner, there’s a camera island. The selfie camera of Galaxy S21 Ultra is right in the middle, while the OnePlus 9 Pro puts the punch hole at the top left corner. The OnePlus 9 Pro comes with 6.7-inch display with 1440p resolution and 120Hz refresh rate. The Samsung Galaxy S21 Ultra comes with 6.8-inch LTPO panel with 3200 x 1440 resolution, dynamic 10Hz to 120Hz refresh rate and HDR 10+ support.

Internal hardware and battery life

Both flagships have Qualcomm Snapdragon 888 and built-in X60 5G modem. The Samsung Galaxy S21 Ultra starts from 12GB RAM/128GB storage all the way to 16GB RAM/512GB storage. There only two variants of OnePlus 9 Pro, 8GB RAM/128GB storage and 12GB RAM/256GB storage. The battery for Galaxy S21 Ultra has 5000mAh capacity, while the 9 Pro is slightly lower at 4500mAh. Combined with the efficient LTPO display, the Galaxy S21 Ultra has longer battery life. However, the OnePlus 9 Pro supports 65W wired charging that can top up the battery in 30 minutes. The 50W wireless charging can fill up the battery in 45 minutes. The wired charger for Galaxy S21 Ultra has lower 25W, while the Qi wireless charging is only at 15W. It is more convenient to fully charge the OnePlus 9 Pro during the day while working, having lunch or taking a short nap.

OnePlus 9 Pro


The 9 Pro has four cameras on the back, 48Mp wide, 50Mp ultra-wide, 8Mp telephoto with 3.3 optical zoom and 2Mp macro. The Samsung Galaxy S21 Ultra also has four cameras, 108Mp wide, 10Mp telephoto periscope with 10x optical zoom, 10Mp telephoto with 3x optical zoom and 12Mp ultra-wide. With the Sony IMX789 sensor, the OnePlus 9 Pro can better prevent aberrations and distortions that often affect wide lenses.


Compared to the Galaxy S21 Ultra, the 9 Pro can charge three times faster with wireless method and twice faster with wired charging. The ultrawide camera also performs better and the display has better refresh controls. The 9 Pro is more compact and lighter as well. If you want longer battery life, the Galaxy S21 Ultra is a better choice and for better multitasking, Samsung’s flagship has more RAM. The 108Mp primary camera and telephoto periscope with 10x physical zoom are better solutions than those on 9 Pro. The S Pen stylus support works well for business professionals.