The best replacement for shadowplay is fraps.

The best alternatives to shadowplay are rated as following:
★★★★★  fraps
★★★★  obs
★★★★  bandicam
★★★★  xsplit
★★★  msi afterburner
★★★  avermedia
★★★  capture card
★★★  mirillis action
★★  quicksync
★★  rls
★★  rmp
★  tsg
★  lsd2
  shatterplay

Your alternative for shadowplay is not listed? Suggest!
Speaking about shadowplay, one probably shouldn't forget about twitch.

Other search terms related to shadowplay and their ratings are:
★★★★★ twitch
★★★★ obs
★★★ twitch not working
★ geforce experience
You have in mind a companion for shadowplay and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of shadowplay in all years. Click on graph for more.
shadowplay
fraps
obs