Design
- Follows Oppo's recent aesthetics and design language with a striking gradient design at the back - the 3D injection-moulded back creates some cool effects when held against light
- The plastic body is also well put-together and the phone has a good heft to it
- The placement of buttons is also good and so is their build quality
- The cheapest phone yet to support a modern in-display fingerprint sensor - which works reasonably well - in line with other in-display fingerprint sensor phones
- There is also some solid face recognition - that tends to be a lot quicker and more convenient most of the time - it's very quick, and works in low light by bumping up the screen brightness to illuminate your face
- Like all glossy backs, the phone of course does pick up fingerprints quite easily, if you use it without a case
- The phone also does feel a bit large when you hold it, so one-handed operation isn't very easy
Display
- Very good, crisp and vivid AMOLED display - produces bright, saturated, punchy colours - and sunlight legibility is also very good
- The display has good touch response too, which was evident when typing
- The large 6.41-inch display is pretty great for watching videos on - the large screen combined with the small water-drop notch at the top means there's plenty of screen real-estate available for use - the bezels are minimal as well
Software
- ColorOS has some useful add-on features like Game Space, Hyper Boost game optimisation feature, Smart Sidebar (pop-out tray for app shortcuts), Smart Scan (which lets you do some multi-lingual translations), and ORoaming (which creates a virtual SIM card with affordable data packs when you're overseas)
- On the whole though, ColorOS is still fairly clunky and there is stuff like ad notifications from Oppo's custom app store and custom browser, that will make you miss the simplicity of a more stock Android UI, if you have experienced that before
Performance
- Excellent performance for the price bracket with the rock solid Snapdragon 660 - everything from daily use to heavy games is handled effortlessly - the phone also doesn't get too hot when gaming even for more than 30 minutes at a stretch
Camera
- Decent dual rear camera at the back, especially in daylight - the main camera captures good details in close-ups - edges are well defined and colours aren't exaggerated - Landscapes also packed in a fair bit of detail, and HDR seems to do a decent job of balancing the exposure
- The second 2-megapixel sensor at the rear is only used for edge detection when shooting in Portrait mode - it does a decent job with objects and people, with a few minor misses at times (however, the camera takes a while to focus in this mode, even when shooting in good light)
- Decent 25MP selfie camera too - overall image quality is good in daylight, and skin textures look natural (with beauty mode turned off) - you can also have a background blur for selfies (but the edge detection isn't the most accurate)
- Decent video recording quality at resolution of up to 4K - stabilisation is only upto 1080p though
- Average low light performance for both the rear cameras and the selfie camera
- You can't use the shutter button several times in rapid succession to take multiple pictures as there's a wait of about a second or two before the camera processes your photo and is ready to go again
Audio
- Fairly loud speaker (though audio quality is average at best, sounding a bit tinny and one-sided, since there's only one speaker at the bottom)
Battery
- Good battery life with a 3600mAh battery - for most users this will translate to well over a day's worth of actual usage
- No fast charging support - takes about 2.5 hours to charge fully
Verdict
- Overall, the Oppo K1 is a pretty decent choice in the competitive mid-range - you get a fast phone with a good battery life, a great AMOLED display, and a cutting edge in-display fingerprint sensor - though the low-light camera performance, and the lack of fast charging will leave you wanting more - whether it makes it to your shortlist might therefore depend on your priorities