Model comparison
GPT-5.5 Pro vs o3-pro
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 42.9 on the Noometry Index. o3-pro costs 1.9× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 5 shared benchmarks.
Summary
- They share 5 benchmarks with published results for both. GPT-5.5 Pro scores higher in 2 categories and o3-pro in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 23.8.
- The biggest single-benchmark swing is ARC-AGI-2: 84.6% for GPT-5.5 Pro and 4.9% for o3-pro.
- o3-pro is cheaper at $20 / $80 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro accepts more context: 1.05M tokens versus 200K.
Side by side
| GPT-5.5 Pro | o3-pro | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 64.3 | 42.9 |
| Released | 2026-04-23 | 2025-06-10 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 200K |
| Max output | 128K | 100K |
| Input $ / M tokens | $30 | $20 |
| Output $ / M tokens | $180 | $80 |
| Results tracked | 14 | 12 |
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Category by category
Coding Not comparable
GPT-5.5 Pro: —, o3-pro: 55.5 (#24)
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| WeirdML | — | 58.2% |
Reasoning GPT-5.5 Pro leads
GPT-5.5 Pro: 73.3 (#10), o3-pro: 23.8 (#171)
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| ARC-AGI-2 | 84.6% | 4.9% |
| ARC-AGI-1 | 96.5% | 59.3% |
| DTBench | 96% | 86.9% |
| LMCA | 53.9% | 38.5% |
| Epoch Capabilities Index | 162.07 | 147.42 |
| SimpleBench | 76.9% | — |
| Kagi LLM Benchmark | — | 72.1% |
| CritPt | 30.6% | — |
| Chess Puzzles | 64% | — |
Math Not comparable
GPT-5.5 Pro: 84.0 (#10), o3-pro: —
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | — |
| FrontierMath Tier 4 | 78% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| FrontierMath (Feb 2025 set) | 52.4% | — |
| FrontierMath Tier 4 (v1) | 39.6% | — |
Knowledge GPT-5.5 Pro leads
GPT-5.5 Pro: 64.1 (#19), o3-pro: 29.5 (#238)
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| GPQA Diamond | 93.9% | — |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
Long Context Not comparable
GPT-5.5 Pro: —, o3-pro: 72.2 (#1)
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
Writing & Preference Not comparable
GPT-5.5 Pro: —, o3-pro: 57.1 (#133)
| Benchmark | GPT-5.5 Pro | o3-pro |
|---|---|---|
| Short-Story Creative Writing | — | 84.4% |
Frequently asked questions
Is GPT-5.5 Pro better than o3-pro?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 42.9 on the Noometry Index. o3-pro costs 1.9× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5.5 Pro or o3-pro?
o3-pro is cheaper. It lists at $20 per million input tokens and $80 per million output tokens; GPT-5.5 Pro lists at $30 and $180.
Which has the bigger context window?
GPT-5.5 Pro does, with 1.05M tokens against 200K.
How many benchmarks do GPT-5.5 Pro and o3-pro share?
5 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and o3-pro has 12.