Half a point apart overall. Synthesia wins on avatar realism and polish, HeyGen wins on translation and price.
Side by side
The full comparison
Criterion
Synthesia
HeyGen
Overall score
9.1
8.6
Avatar realism
8.9
8.5
Translation lip-sync
Good
Best in test
Entry price
$29/mo
$24/mo
Custom avatar
Paid add-on
Included from Creator
Free tier
3 min/mo
3 videos/mo
API
Yes
Yes
Best for
Training video
Localisation
Side by side
The full comparison
Same criteria, same workload, same reviewer. Filter to narrow the field.
Synthesia
Overall score
9.1
Avatar realism
8.9
Translation lip-sync
Good
Entry price
$29/mo
Custom avatar
Paid add-on
Free tier
3 min/mo
API
Yes
Best for
Training video
HeyGen
Overall score
8.6
Avatar realism
8.5
Translation lip-sync
Best in test
Entry price
$24/mo
Custom avatar
Included from Creator
Free tier
3 videos/mo
API
Yes
Best for
Localisation
Trade-offs
Pros and cons
Synthesia
What works
Fastest script-to-video pipeline tested
Fastest iteration loop; edits land in seconds
File and spreadsheet analysis is genuinely reliable
What doesn't
Brand voice drifts across long sessions without a custom instruction set
Factual claims still need checking on anything specialised
Usage limits on the strongest model can bite mid-project
Claude Pro
What works
Holds tone and structure across very long documents
Least likely to invent a citation when asked not to
Excellent at critique — it will tell you a draft is weak
What doesn't
Image generation is absent; you will need a second subscription
Slower on short prompts than the alternatives
Occasionally over-hedges on straightforward factual questions
Verdict
The winner
Winner · 9 . 0 / 1 0
Claude Pro
For the writing workload this site tests, Claude takes it on output quality and long-document consistency. If your team needs images, code and analysis from one subscription, reverse the verdict.