Both are commercial model provider options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence.
Claude Opus, Sonnet and Haiku. Strong tool use and long-horizon agentic work.
Enable prompt caching on the system prompt and tool definitions — it is the single biggest cost lever.
One API key, several hundred models, automatic failover.
| Anthropic | OpenRouter | |
|---|---|---|
| Licence | Proprietary | Proprietary |
| Pricing | usage based | usage based |
| Self-hostable | No | No |
| Languages | TypeScript, Python | TypeScript, Python |
| Install | npm install @anthropic-ai/sdk | — |
| Keys required | ANTHROPIC_API_KEY | OPENROUTER_API_KEY |
Both are commercial model provider options with comparable terms, so the choice comes down to which model of the problem you prefer — compare the descriptions below rather than the licence. Anthropic: Claude Opus, Sonnet and Haiku. Strong tool use and long-horizon agentic work. OpenRouter: One API key, several hundred models, automatic failover.
Anthropic is a hosted service only. OpenRouter is a hosted service only.
Anthropic is proprietary (usage based). OpenRouter is proprietary (usage based).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/anthropic-vs-openrouter