Claude 4.1 Opus vs GPT-5.1
Head-to-head specifications
| Metric | Claude 4.1 Opus | GPT-5.1 | Difference |
|---|---|---|---|
| Intelligence Index | 30.0 | 37.0 | -18.9% |
| Context window | 262K tokens | 512K tokens | — |
| Blended price ($/1M tokens) | $1.68 | $0.77 | +118.2% |
| Output speed (tokens/s) | 30 | 106 | -71.7% |
| Access | Proprietary API | Proprietary API | — |
- GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 30.0).
- GPT-5.1 is the cheaper model to run at $0.77/1M blended tokens — about 2.2× cheaper.
- GPT-5.1 offers the larger context window (512K tokens), useful for long documents and codebases.
Verdict: Claude 4.1 Opus or GPT-5.1?
Claude 4.1 Opus advantages
- No decisive advantage on the tracked metrics.
GPT-5.1 advantages
- General intelligence (+19%)
- Context window (+49%)
- Affordability (+54%)
- Output speed (+72%)
Which should you choose?
- Choose the GPT-5.1 if you need the strongest overall reasoning and accuracy.
Value for money
GPT-5.1 offers more intelligence per dollar (2.7× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Claude 4.1 Opus vs GPT-5.1: which should you choose?
Claude 4.1 Opus — Anthropic multimodal model with an Intelligence Index of 30, a 262K-token context window and a blended price of $1.68/1M tokens.
GPT-5.1 — OpenAI multimodal model with an Intelligence Index of 37, a 512K-token context window and a blended price of $0.77/1M tokens.
Claude 4.1 Opus vs GPT-5.1: GPT-5.1 scores higher on the Intelligence Index. GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 30.0). GPT-5.1 is the cheaper model to run at $0.77/1M blended tokens — about 2.2× cheaper.
Capability: intelligence, coding and agentic work
On the composite Intelligence Index the GPT-5.1 scores 37.0 versus 30.0. Composite indices summarize many evaluations, but always test on your own workload before committing.
Context window and speed
The GPT-5.1 accepts up to 512K tokens per request, which sets how much documentation, transcript or code it can reason over at once. In measured throughput, GPT-5.1 generates faster (106 vs 30 tokens/s), which matters for interactive apps and high-volume pipelines.
Pricing and access
At blended per-token rates, GPT-5.1 is the cheaper model to run ($0.77 vs $1.68 per 1M tokens). Claude 4.1 Opus is proprietary api and GPT-5.1 is proprietary api. Open-weight models can be self-hosted, trading per-call cost for infrastructure you manage; for production also weigh rate limits, throughput and data-residency requirements.
The verdict
Both are credible choices in the ai model comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the Claude 4.1 Opus better than the GPT-5.1?
GPT-5.1 is the clearly stronger overall choice, winning most of the dimensions that matter. GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 30.0).
What is the main difference between the Claude 4.1 Opus and the GPT-5.1?
GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 30.0). GPT-5.1 is the cheaper model to run at $0.77/1M blended tokens — about 2.2× cheaper.
Which is better value?
GPT-5.1 offers more intelligence per dollar (2.7× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Which should I choose?
Choose the GPT-5.1 if you need the strongest overall reasoning and accuracy.
Methodology
Large language models are compared on independent leaderboard metrics: an Intelligence Index (a composite of reasoning and knowledge evaluations), Coding and Agentic indices where measured, community arena Elo, maximum context window, a blended API price per million tokens (weighted across cache-hit, input and output rates), and measured output speed in tokens per second. Where a model ships multiple reasoning-effort variants, we report its strongest variant. Benchmarks capture only part of real-world quality, which also depends on tool use, latency, safety and task fit — and this space moves quickly, so figures reflect the leaderboard snapshot on the page date.