OpenAI API vs Anthropic API
Both platforms allow commercial use, assign output ownership to the customer, and do not use API inputs for training by default. Differences are in model families, tooling, and pricing.
Key differences
- Model families: GPT-5/GPT-4o family (OpenAI) vs Claude 4 Opus/Sonnet/Haiku family (Anthropic).
- Both offer prompt caching, function/tool calling, streaming, and vision.
- Pricing structure differs per model; see each provider's pricing page.
- API inputs are not used for training by default on either provider.
Rights
| Key | OpenAI API | Anthropic API |
|---|---|---|
commercial_use_allowed |
yes | yes |
output_ownership |
yes | yes |
redistribution_allowed |
conditional | — |
training_use_of_input |
no | no |
Constraints
| Key | OpenAI API | Anthropic API |
|---|---|---|
api_available |
yes | yes |
webhook_available |
yes | — |