o3-mini vs GPT-5.1
Head-to-head specifications
| Metric | o3-mini | GPT-5.1 | Difference |
|---|---|---|---|
| Intelligence Index | 24.0 | 37.0 | -35.1% |
| Coding Index | 16.3 | 49.4 | -67.0% |
| Agentic Index | 1.7 | 21.0 | — |
| Context window | 256K tokens | 512K tokens | — |
| Blended price ($/1M tokens) | $0.70 | $0.77 | -9.1% |
| Output speed (tokens/s) | 211 | 106 | +99.1% |
| Access | Proprietary API | Proprietary API | — |
- GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 24.0).
- o3-mini is the cheaper model to run at $0.70/1M blended tokens — about 1.1× cheaper.
- GPT-5.1 offers the larger context window (512K tokens), useful for long documents and codebases.
Verdict: o3-mini or GPT-5.1?
o3-mini advantages
- Affordability (+9%)
- Output speed (+50%)
GPT-5.1 advantages
- General intelligence (+35%)
- Coding ability (+67%)
- Agentic task performance (+92%)
- Context window (+50%)
Which should you choose?
- Choose the o3-mini if you want the lowest cost per token at scale.
- Choose the GPT-5.1 if you need the strongest overall reasoning and accuracy.
- Choose the o3-mini if low latency and fast generation matter for your application.
Value for money
GPT-5.1 offers more intelligence per dollar (1.4× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
o3-mini vs GPT-5.1: which should you choose?
o3-mini — OpenAI multimodal model with an Intelligence Index of 24, a 256K-token context window and a blended price of $0.7/1M 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.
o3-mini vs GPT-5.1: GPT-5.1 scores higher on the Intelligence Index. GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 24.0). o3-mini is the cheaper model to run at $0.70/1M blended tokens — about 1.1× cheaper.
Capability: intelligence, coding and agentic work
On the composite Intelligence Index the GPT-5.1 scores 37.0 versus 24.0. For software development, the Coding Index puts GPT-5.1 ahead (49.4 vs 16.3). On agentic, multi-step tool-use tasks, GPT-5.1 measures stronger. 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, o3-mini generates faster (211 vs 106 tokens/s), which matters for interactive apps and high-volume pipelines.
Pricing and access
At blended per-token rates, o3-mini is the cheaper model to run ($0.70 vs $0.77 per 1M tokens). o3-mini 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 o3-mini better than the GPT-5.1?
GPT-5.1 takes the overall edge, though o3-mini wins in specific areas worth weighing. GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 24.0).
What is the main difference between the o3-mini and the GPT-5.1?
GPT-5.1 leads overall capability (Intelligence Index 37.0 vs 24.0). o3-mini is the cheaper model to run at $0.70/1M blended tokens — about 1.1× cheaper.
Which is better value?
GPT-5.1 offers more intelligence per dollar (1.4× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Which should I choose?
Choose the o3-mini if you want the lowest cost per token at scale. 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.