o3 Pro
OpenAI o3 Pro: maximum-compute variant of o3, built for reliability over speed, 4/4 consistency scoring, Responses API only, science, math, and coding.
Model Overview
Capabilities, design details, and architectural traits
o3 Pro - Running at Maximum Compute for Consistent Reliability
o3 Pro is OpenAI's highest-compute variant of o3. It uses the same underlying model as o3 but is explicitly designed to think longer and trade speed for consistency. OpenAI positions it for challenging questions where reliability matters more than speed.
| Trait | Detail |
|---|---|
| Defining design principle | More compute per request to produce consistently better answers, not just occasionally better ones |
| Reliability evaluation method | 4/4 scoring - a response is counted as successful only if the model answers correctly in all four attempts, not just one |
| API availability | Responses API only - not available via Chat Completions; enables multi-turn reasoning before responding |
| Latency posture | Slowest in the o3 family; OpenAI recommends background mode to avoid timeouts |
| Tool access | Web search, file analysis, Python, visual reasoning - all documented for this model |
| Streaming | Not supported |
The 4/4 Reliability Standard
The 4/4 reliability evaluation is the specific metric OpenAI uses to characterize o3 Pro's advantage over standard o3. It measures whether a model gets a question right across all four sampled attempts - not just one. This framing, consistent correct outputs rather than peak correct outputs, is the documented reason the model exists as a separate tier.
Benchmark Performance
Independent evaluations · Artificial Analysis
Accuracy & Capability Details
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Evaluate specifications, pricing, and independent benchmark indices
| Model Details | |||
|---|---|---|---|
| General Info | |||
| Provider | OpenAI | Anthropic | Anthropic |
| Release Date | June 10, 2025 | September 22, 2026 | September 28, 2026 |
| Knowledge Cutoff | Jun 2024 | - | Jun 2026 |
| Context & Limits | |||
| Context Window | 200K | 1M Best Context Window | 1M Best Context Window |
| Pricing (per 1M tokens) | |||
| Input Pricing | $20 | $4 | $2 Best Input Pricing |
| Output Pricing | $80 | $20 | $10 Best Output Pricing |
| Modalities | |||
| Inputs | textfileimage | textimagefile | textimagefile |
| Outputs | text | text | text |
| Benchmarks (0-100) | |||
| Intelligence Index | 21.9 | 57.6 Best Intelligence Index | 56.0 |
| Coding Index | - | - | - |
| Agentic Index | - | - | - |
Humanity's Last Exam
Extremely difficult logical reasoning and knowledge.
Long Context Reasoning
Logical reasoning over long context windows.
SciCode Benchmark
Scientific coding and mathematical modeling.
Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.
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