How they really differ
HeyGen is a creation tool and OpusClip is a repurposing tool, so they rarely replace each other. The real question is which step is slowing you down.
OpusClip works best on long, conversational videos with natural standalone moments. Short scripted avatar videos usually have fewer clips to find.
Both run on plan limits, such as video credits or processing minutes. Map your weekly output against each before paying.
Using both
Publish a full-length video with a HeyGen presenter, then run it through OpusClip to pull Shorts for the week.
The verdict
HeyGen to make the video, OpusClip to multiply it. New faceless channels usually need creation first; channels with a back catalog get more from OpusClip.
Want the full write-up on each? Read our HeyGen review and OpusClip review.