720p vs 1080p vs 4K

Name	Pixels	Megapixels	vs 1080p
720p HD	1280 × 720	0.9	0.44×
1080p Full HD	1920 × 1080	2.1	1×
1440p QHD	2560 × 1440	3.7	1.78×
4K UHD	3840 × 2160	8.3	4×
8K	7680 × 4320	33.2	16×

Which should you use?

• Film in the highest resolution your camera does well (4K on most modern phones), which gives room to crop and stabilise.
• Edit in the resolution you deliver.
• Upload 4K to YouTube even for 1080p viewers, because of the higher bitrate. Social feeds mostly play 1080p or less.

The "p" stands for progressive scan, as opposed to "i" (interlaced) used by older TV formats like 1080i and 576i.