100% 0 nobody lose much of clarity esp if u record big file in phone 
for cli PROs  use ffmpeg CLI on u console in linux then upload to fave blosson or cdn or nostrcheckme server 
e.g. ffmpeg -i laserharp5a.mp4 -vcodec libx264 -crf 20 laserharp5b.mp4
do it few times to make size much smaller