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Claude 2.1 vs GPT-5.1-Codex-Max

Anthropic Claude 2.1 vs OpenAI GPT-5.1-Codex-Max — side-by-side specs.

Anthropic
Claude 2.1
OpenAI
GPT-5.1-Codex-Max
Overview
CompanyAnthropicOpenAI
Release dateNov 21 2023Nov 19 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Timeline
Release gapClaude 2.1 shipped 729 days before GPT-5.1-Codex-Max

Which is better: Claude 2.1 or GPT-5.1-Codex-Max?

Claude 2.1 and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 729 days before GPT-5.1-Codex-Max, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude 2.1 and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks.

Frequently asked questions

When was Claude 2.1 released?
Claude 2.1 was released by Anthropic on Nov 21 2023.
When was GPT-5.1-Codex-Max released?
GPT-5.1-Codex-Max was released by OpenAI on Nov 19 2025.

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