OpenAI o4-mini is cheaper than Claude Sonnet 4.5 at $1.1/M vs $3/M input tokens.
| Spec | Claude Sonnet 4.5 | OpenAI o4-mini |
|---|---|---|
| Input price | $3/M tokens | $1.1/M tokens |
| Output price | $15/M tokens | $4.4/M tokens |
| Context window | 200K tokens | — |
| Weights | Closed | Closed |
| Free API (OpenRouter) | No | No |
| Released | Sep 2025 | Apr 2025 |
| SWE-bench Verified | 77.2% | 68.1% |
Not enough votes to call it. On the specs, Claude Sonnet 4.5 has the edge: bigger model tier, newer, bigger context window.
OpenAI o4-mini costs 3.4x less per token.
OpenAI o4-mini is cheaper on both: 2.7× input, 3.4× output.
Per million tokens. Prices and uptime via OpenRouter, checked 8 Sep 2026.
Claude Sonnet 4.5 uses 490.1x more bold