Claude Opus 4.6 vs GPT-5.1-Codex
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose Claude Opus 4.6 if you need
- ✓nuanced reasoning and high-quality structured outputs on complex tasks
- ✓maximum context handling up to 1 million tokens without coherence loss
- ✓careful, safety-aligned responses on borderline or sensitive topics
- ✓effective processing of very large multimodal inputs
Choose GPT-5.1-Codex if you need
- ✓fast output at 178 tokens per second for extended workflows
- ✓lower cost at $10 per million tokens for high-volume use
- ✓specialized coding performance with integrated visual context
- ✓large-scale text and image tasks in software development
Verdict
Claude Opus 4.6 leads on raw intelligence (52.9 vs 43.1) and maximum context length (1M tokens), making it stronger for nuanced reasoning and very large inputs. GPT-5.1-Codex wins decisively on speed (178 t/s vs 40 t/s) and price ($10 vs $25 per million tokens) while offering specialized coding and vision integration. The choice hinges on whether the task prioritizes depth and safety or velocity and cost-efficient software workflows.
Claude Opus 4.6 vs GPT-5.1-Codex: side by side
| Spec | Claude Opus 4.6 | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Intelligence | 52.9 | 43.1 | Claude Opus 4.6 |
| Output speed | 40 t/s | 178 t/s | GPT-5.1-Codex |
| Output price | $25.00/1M | $10.00/1M | GPT-5.1-Codex |
| Context | 1000K | 400K | Claude Opus 4.6 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: Claude Opus 4.6Claude Opus 4.6 scores 52.9 on the intelligence index compared with 43.1 for GPT-5.1-Codex. This gap favors Claude on nuanced reasoning and structured outputs. GPT-5.1-Codex instead emphasizes coding specialization.
Speed
Winner: GPT-5.1-CodexGPT-5.1-Codex delivers 178.06 tokens per second versus 40.23 for Claude Opus 4.6. The fourfold speed advantage makes GPT-5.1-Codex preferable for high-throughput applications. Claude's slower pace is noted as a limitation on complex queries.
Pricing & Context
Winner: GPT-5.1-CodexGPT-5.1-Codex costs $10 per million tokens against $25 for Claude Opus 4.6, while offering a 400k context window. Claude provides a larger 1M-token context at double the price. Both models are closed and proprietary.
Task Specialization
Winner: TieClaude Opus 4.6 excels at safety-aligned reasoning and large-input handling. GPT-5.1-Codex is optimized for extended coding workflows and visual-code integration. Neither model offers native real-time web access or non-text/image inputs.
Claude Opus 4.6
Pros
- +Strong performance on nuanced reasoning tasks
- +Careful and safety-aligned responses
- +Effective handling of large inputs
- +High-quality structured outputs
Cons
- –Slower response times on complex queries
- –More conservative on borderline topics
- –No native real-time web access
GPT-5.1-Codex
Pros
- +Strong performance on extended coding workflows
- +Effective integration of visual context with code
- +Handles very large inputs without losing coherence
- +Specialized for software development tasks
Cons
- –Limited to text and image inputs only
- –High computational cost for maximum context
- –May require careful prompt engineering for complex tasks
Summary: Claude Opus 4.6 vs GPT-5.1-Codex
Select Claude Opus 4.6 when intelligence, maximum context, and cautious responses matter most. Choose GPT-5.1-Codex when speed, lower cost, and coding-focused multimodal work are priorities. The models serve overlapping but distinct multimodal use cases.
Frequently asked questions
Claude Opus 4.6 scores higher on intelligence (52.9) and context size (1M), while GPT-5.1-Codex is faster and cheaper; neither is universally better.