Claude Sonnet 4.5 (latest) vs GPT-5.3 Codex
GPT-5.3 Codex is cheaper on output tokens, while Claude Sonnet 4.5 (latest) offers a larger context window. Choose Claude Sonnet 4.5 (latest) or GPT-5.3 Codex based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Claude Sonnet 4.5 (latest) | GPT-5.3 Codex |
|---|---|---|
| Provider | OpenRouter | OpenRouter |
| Input / 1M tokens | $3.00 | $1.75 |
| Output / 1M tokens | $15.00 | $14.00 |
| Context window | 1M | 400K |
| Parameters | — | — |
| Open weights | No | No |
| Released | Sep 2025 | Feb 2026 |
FAQ
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.