Some popular hashtags related to birthday video editing are:
#birthdayvideo#birthdayedit
#birthdaymontage
#birthdayslideshow
#birthdaymemories
#birthdaytribute
#birthdaygift
#happybirthday
#birthdaylove
#birthdaywishes
Note: Hashtags can vary by region and change frequently, so it's always a good idea to check for the most up-to-date hashtags before posting.