The OnePlus 9 Pro is a big phone — but this time around, I'd say it's "pleasantly" big with its 6.7" screen. While numerical dimensions aren't' that different from the 8 Pro or 7 Pro, it is slightly shorter and narrower, which makes a surprising difference. The OnePlus 9 Pro is much easier to hold for a Plus/Max/Ultra-sized phone, and right at the upper edge of what I'd consider comfortable. It's large, but it's not unwieldy, and just the right weight for the size.
- Android Police: OnePlus 9 Pro, what's in the box - Apr 30, 2021

The OnePlus 9 Pro is a culmination of the company’s efforts over the past couple of years, and it’s the first time a smartphone from the company has felt like the complete package. It offers top-end power, a great camera experience and all the bells and whistles you’d expect from a flagship smartphone right now. This is a handset that can genuinely compete with the very best phones from the biggest brands.
- Tech Radar: OnePlus 9 Pro in Two-minute - April, 2021

The hardware design on the OnePlus 9 Pro is the most seamless, elegant phone that the company has designed to date. It is, of course, big. It has a 6.7-inch screen that goes from edge to edge in a body that’s narrow enough to make it just barely usable for me in one hand. The OnePlus 9 Pro has the top-tier Qualcomm Snapdragon 888 processor, which is paired with eight gigs of RAM on the 128GB model. You can’t get it in a smaller screen size, but you can spend $100 more to get 256GB of storage and 12GB of RAM. There’s no microSD card slot for storage expansion in either model. What you get is what you get.
- The Verge: OnePlus 9 Pro hardware design and 5G support - Mar 26, 2021

The 9 Pro also has by far the fastest charging speeds of any phone we've ever tested. It comes with a Warp Charge 65T USB-C charger, which charges the 9 or the 9 Pro from 0% to 20% in six minutes and to 100% in just 36 minutes. That's twice as fast as any recent Samsung phone charges. If you use a third-party charger, the phone will charge at up to 18 watts, with correspondingly longer charge times.
- PCMag: OnePlus 9 Pro, Ultra-Super-Mega-Fast Charging - April 6, 2021

The one thing that impresses above everything else about the OnePlus 9 Pro is its screen. This not only is large and very, very, very bright — there really is no need for anyone to use it on 100% brightness indoors unless he/she wants to gape at how it handles certain Netflix films with spectacular HDR highlights — but also of high resolution, making everything seem almost printed just underneath the glass. Those 1440 lines of pixels do drain the 9 Pro’s battery faster than the typical 1080 ones and there’s always the option to revert to that resolution but… come on: there’s no point in paying for such a quality screen only to keep it from offering its best (especially when charging is so amazingly fast — more on that later).
- Farkonas: OnePlus 9 Pro, Screen, audio, expandability - May 6, 2021

If you heard rumors about the quality of the OnePlus 9 Pro’s display leading up to its launch, know that all of that hubbub ended up being true. The OnePlus 9 Pro’s display looks fantastic, both in our lab testing and in my personal use. It’s bright with rich colors, deep blacks, and a smart 120Hz adaptive refresh rate.
- Toms Guide: OnePlus 9 Pro Display - May, 2021

The OnePlus 9 Pro is a no-holds-barred premium device and is one of the best phones you can buy right now. There are two Pro variants — the 8GB/128GB model and the 12GB/256GB model The 6.7-inch QHD+ AMOLED panel is beautiful with punchy colors, deep blacks, and a 120Hz adaptive refresh rate. It matches the Galaxy S21 Plus and beats the iPhone 12 Pro in our testing. The OnePlus 9 Pro’s camera performance is solid. Colors are a subdued, natural tone. Nightscape is inconsistent, though. Based on our lab testing, the OnePlus 9 Pro is the one of the most powerful Android phones we’ve tested yet, even matching the ROG Phone 5 powerhouse. With a 4,500 mAh battery, the OnePlus 9 Pro went for 10 hours and 40 minutes in 120Hz mode in our battery test. It can charge from empty to 50% in 15 minutes and to 99% in 30 minutes on the 65W charger. The OnePlus 9 Pro ships with Android 11 and OxygenOS 11. It will receive two years of OS updates (Android 13) and three years of security patches (2024).
- Toms Guide: OnePlus 9 Pro cheat sheet - May, 2021