Model comparison
GPT-5.5 Pro vs GPT-5 Pro
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 46.4 on the Noometry Index. GPT-5 Pro costs 1.6× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 7 shared benchmarks.
Summary
- They share 7 benchmarks with published results for both. GPT-5.5 Pro scores higher in 3 categories and GPT-5 Pro in 0 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5.5 Pro leads 84.0 to 48.5.
- The biggest single-benchmark swing is ARC-AGI-2: 84.6% for GPT-5.5 Pro and 18.3% for GPT-5 Pro.
- GPT-5 Pro is cheaper at $15 / $120 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro accepts more context: 1.05M tokens versus 400K.
Side by side
| GPT-5.5 Pro | GPT-5 Pro | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 64.3 | 46.4 |
| Released | 2026-04-23 | 2025-10-06 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 400K |
| Max output | 128K | 272K |
| Input $ / M tokens | $30 | $15 |
| Output $ / M tokens | $180 | $120 |
| Results tracked | 14 | 12 |
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Category by category
Coding Not comparable
GPT-5.5 Pro: —, GPT-5 Pro: 44.0 (#80)
Reasoning GPT-5.5 Pro leads
GPT-5.5 Pro: 73.3 (#10), GPT-5 Pro: 38.9 (#62)
| Benchmark | GPT-5.5 Pro | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | 84.6% | 18.3% |
| SimpleBench | 76.9% | 61.6% |
| ARC-AGI-1 | 96.5% | 70.2% |
| Epoch Capabilities Index | 162.07 | 150.28 |
| Kagi LLM Benchmark | — | 76.8% |
| CritPt | 30.6% | — |
| Chess Puzzles | 64% | — |
| EnigmaEval | — | 18.8% |
| DTBench | 96% | — |
| LMCA | 53.9% | — |
Math GPT-5.5 Pro leads
GPT-5.5 Pro: 84.0 (#10), GPT-5 Pro: 48.5 (#63)
| Benchmark | GPT-5.5 Pro | GPT-5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | 55.8% |
| FrontierMath Tier 4 | 78% | 19.5% |
| FrontierMath Tier 4 (v1) | 39.6% | 14.6% |
| OTIS Mock AIME 2024-2025 | 100% | — |
| FrontierMath (Feb 2025 set) | 52.4% | — |
Knowledge GPT-5.5 Pro leads
GPT-5.5 Pro: 64.1 (#19), GPT-5 Pro: 56.7 (#42)
| Benchmark | GPT-5.5 Pro | GPT-5 Pro |
|---|---|---|
| GPQA Diamond | 93.9% | — |
| Humanity's Last Exam | — | 31.6% |
Frequently asked questions
Is GPT-5.5 Pro better than GPT-5 Pro?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 46.4 on the Noometry Index. GPT-5 Pro costs 1.6× 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 GPT-5 Pro?
GPT-5 Pro is cheaper. It lists at $15 per million input tokens and $120 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 400K.
How many benchmarks do GPT-5.5 Pro and GPT-5 Pro share?
7 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and GPT-5 Pro has 12.