GPT-5.1-Codex-Max
OpenAI • codigo
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...
Specifications
Context Window
400K tokens
Input Price/1M
$1.25
Output Price/1M
$10.00
Parameters
—
Max Output
128K tokens
Benchmarks
GPT-5.1-Codex-Max results on the main AI model evaluation benchmarks. Higher scores indicate better performance.
Coding
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveCodeBench | 84.9 | 100.0 | Artificial Analysis official API |
| LiveBench Coding | 80.7 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
| AA Coding Index | 36.6 | 100.0 | Artificial Analysis official API |
Data Analysis
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Data Analysis | 70.1 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Language
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Language | 76.5 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Math
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AIME 2025 | 95.7 | 100.0 | Artificial Analysis official API |
| AA Math Index | 95.7 | 100.0 | Artificial Analysis official API |
| LiveBench Math | 83.2 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
overall
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Global | 74.0 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
| AA Intelligence Index | 43.1 | 100.0 | Artificial Analysis official API |
Reasoning
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| GPQA Diamond | 86.0 | 100.0 | Artificial Analysis official API |
| MMLU Pro | 86.0 | 100.0 | Artificial Analysis official API |
| LiveBench Reasoning | 83.7 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Information
- Release date
- December 04, 2025
- Tool Calling
- ✅ Supported
- Vision
- ✅ Supported
- Audio
- ❌ Not supported
Full Analysis: GPT-5.1-Codex-Max
What is GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max is an AI model developed by OpenAI, classified as a codigo model. It is a multimodal model, capable of processing text, images, and potentially other media types. As a proprietary model, it is available via OpenAI's cloud API. With a context window of 400K tokens, it is suitable for processing long documents such as contracts, books, and complete codebases.
Pricing & Costs in 2026
GPT-5.1-Codex-Max is usage-based, priced at $1.25/1M input tokens and $10/1M output tokens. For context: 1 million tokens is approximately 750,000 words, or about 10 average-length books. The mid-range pricing balances quality and cost for most professional applications.
Benchmarks & Performance
GPT-5.1-Codex-Max was evaluated on 13 different benchmarks, covering categories like Coding, Data Analysis, Language, Math, overall, Reasoning. Results show exceptional performance across available evaluations.
It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.
Recommended Use Cases
GPT-5.1-Codex-Max specializes in codigo, offering advanced capabilities for creating and processing codigo content.
Comparison with Alternatives
In the 2026 AI model ecosystem, GPT-5.1-Codex-Max competes directly with similarly capable models. Key competitors include Claude (Anthropic), Gemini (Google), and open source models like Llama (Meta) and Qwen (Alibaba). The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.
For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.
Frequently Asked Questions
What is GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...
How much does GPT-5.1-Codex-Max cost?
GPT-5.1-Codex-Max costs $1.25/1M input tokens and $10/1M output tokens. For heavy usage (e.g., a chatbot handling 100k messages/month), costs can range from $10 to $1,000 depending on volume.
How does GPT-5.1-Codex-Max compare with other models?
In available benchmarks, GPT-5.1-Codex-Max scored: LiveCodeBench: 84.9/100, LiveBench Coding: 80.68/100, AA Coding Index: 36.6/100. See the full table above for a detailed comparison.
Is GPT-5.1-Codex-Max open source?
No, GPT-5.1-Codex-Max is a proprietary model from OpenAI. It is available via cloud API. For open source alternatives, check our open source model ranking.
What is GPT-5.1-Codex-Max best for?
GPT-5.1-Codex-Max excels at complex reasoning and problem solving. With its large context window, it handles long documents, codebases, and extended conversations. It supports tool calling for API integrations and automation.
Last updated: June 01, 2026 • View methodology →