Anthropic: Claude Sonnet 5.5 vs OpenAI: GPT-5.1-Codex-Max
Head-to-head API cost, context, and performance comparison. Synced at 2:07:05 PM.
Executive Summary
When evaluating Anthropic: Claude Sonnet 5.5 against OpenAI: GPT-5.1-Codex-Max, the pricing structure is a key differentiator. OpenAI: GPT-5.1-Codex-Max is approximately 6% more cost-effective per 1 million tokens overall.
However, when looking at raw reasoning capabilities, Anthropic: Claude Sonnet 5.5 leads with a statistical ELO score of 1603. For tasks involving complex logic, coding, or instruction-following, developers might prefer Anthropic: Claude Sonnet 5.5, provided their budget allows for the API burn rate.
Raw Technical comparison
Verdict
If you are looking for pure performance and capability, Anthropic: Claude Sonnet 5.5 is statistically superior. However, if API burn rate is the primary concern, OpenAI: GPT-5.1-Codex-Max wins out aggressively in pricing.
People Also Ask
Is Anthropic: Claude Sonnet 5.5 cheaper than OpenAI: GPT-5.1-Codex-Max?
No. OpenAI: GPT-5.1-Codex-Max is the more cost-effective model, operating at a lower price point per 1 million tokens.
Which model has the larger context window?
The Anthropic: Claude Sonnet 5.5 model has the advantage in memory, offering a massive 1,000,000 token limit for document ingestion.