Model comparison
GPT-5.5 Pro vs GPT-5 Nano
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 33.5 on the Noometry Index. GPT-5 Nano costs 491× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 12 shared benchmarks.
Summary
- They share 12 benchmarks with published results for both. GPT-5.5 Pro scores higher in 3 categories and GPT-5 Nano in 0 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 16.3.
- The biggest single-benchmark swing is ARC-AGI-2: 84.6% for GPT-5.5 Pro and 2.6% for GPT-5 Nano.
- GPT-5 Nano is cheaper at $0.05 / $0.40 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 Nano | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 64.3 | 33.5 |
| Released | 2026-04-23 | 2025-08-07 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 400K |
| Max output | 128K | 128K |
| Input $ / M tokens | $30 | $0.05 |
| Output $ / M tokens | $180 | $0.40 |
| Results tracked | 14 | 49 |
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Category by category
Coding Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 33.6 (#254)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| SWE-bench Verified (bash only) | — | 34.8% |
| WeirdML | — | 38.1% |
| LMArena Coding | — | 1351 |
| ALE-Bench | — | 718.67 |
Agentic & Tool Use Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 25.8 (#106)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| Terminal-Bench | — | 21.8% |
| Berkeley Function Calling Leaderboard | — | 51.5% |
Reasoning GPT-5.5 Pro leads
GPT-5.5 Pro: 73.3 (#10), GPT-5 Nano: 16.3 (#306)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| ARC-AGI-2 | 84.6% | 2.6% |
| ARC-AGI-1 | 96.5% | 20.7% |
| Chess Puzzles | 64% | 27% |
| DTBench | 96% | 62.7% |
| LMCA | 53.9% | 7.9% |
| Epoch Capabilities Index | 162.07 | 139.38 |
| SimpleBench | 76.9% | — |
| Kagi LLM Benchmark | — | 62.2% |
| CritPt | 30.6% | — |
| LMArena Hard Prompts | — | 1328 |
| Mystery Game Puzzles | — | 9% |
| ForecastBench | — | 59.1 |
Math GPT-5.5 Pro leads
GPT-5.5 Pro: 84.0 (#10), GPT-5 Nano: 29.4 (#241)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | 20% |
| FrontierMath Tier 4 | 78% | 2.4% |
| OTIS Mock AIME 2024-2025 | 100% | 81.1% |
| FrontierMath (Feb 2025 set) | 52.4% | 8.3% |
| FrontierMath Tier 4 (v1) | 39.6% | 2.1% |
| ProofBench | — | 12% |
| Omni-MATH | — | 54.6% |
| LMArena Math | — | 1317 |
| MATH Level 5 | — | 95.2% |
Knowledge GPT-5.5 Pro leads
GPT-5.5 Pro: 64.1 (#19), GPT-5 Nano: 35.9 (#178)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| GPQA Diamond | 93.9% | 69.4% |
| SimpleQA Verified | — | 11.7% |
| MMLU-Pro | — | 77.8% |
| Vectara Hallucination Rate | — | 10.5% |
| GPQA (HELM) | — | 67.9% |
| LMArena Expert | — | 1321 |
Multimodal Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 31.3 (#108)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| LMArena Vision | — | 1159 |
| VPCT | — | 37.2% |
Multilingual Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 45.3 (#172)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| LMArena Non-English | — | 1313 |
| LMArena Chinese | — | 1356 |
| LMArena German | — | 1327 |
| LMArena Japanese | — | 1226 |
| LMArena Korean | — | 1269 |
| LMArena Russian | — | 1296 |
| LMArena Spanish | — | 1360 |
Instruction Following Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 75.0 (#79)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| IFEval | — | 93.2% |
| LMArena Instruction Following | — | 1306 |
Long Context Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 31.3 (#281)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| Fiction.LiveBench | — | 44.4% |
| LMArena Longer Query | — | 1312 |
Writing & Preference Not comparable
GPT-5.5 Pro: —, GPT-5 Nano: 39.1 (#249)
| Benchmark | GPT-5.5 Pro | GPT-5 Nano |
|---|---|---|
| LMArena Text | — | 1320 |
| LMArena Creative Writing | — | 1249 |
| EQ-Bench Creative Writing | — | 705 |
| WildBench | — | 80.6% |
| LMArena Multi-Turn | — | 1311 |
Frequently asked questions
Is GPT-5.5 Pro better than GPT-5 Nano?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 33.5 on the Noometry Index. GPT-5 Nano costs 491× 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 Nano?
GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 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 Nano share?
12 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and GPT-5 Nano has 49.