Model comparison
GPT-5.5 Pro vs GPT-6 Sol
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 61.8 on the Noometry Index. GPT-6 Sol costs 17× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 10 shared benchmarks.
Summary
- They share 10 benchmarks with published results for both. GPT-5.5 Pro scores higher in 0 categories and GPT-6 Sol in 3 categories; one gap is clear of the uncertainty.
- The widest gap is in math, where GPT-6 Sol leads 87.2 to 84.0.
- The biggest single-benchmark swing is FrontierMath Tier 4: 78% for GPT-5.5 Pro and 90% for GPT-6 Sol.
- GPT-6 Sol is cheaper at $2 / $10 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
Side by side
| GPT-5.5 Pro | GPT-6 Sol | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 64.3 | 61.8 |
| Released | 2026-04-23 | 2026-09-22 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 1.05M |
| Max output | 128K | 128K |
| Input $ / M tokens | $30 | $2 |
| Output $ / M tokens | $180 | $10 |
| Results tracked | 14 | 45 |
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Category by category
Coding Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 60.1 (#11)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| DeepSWE | — | 68.8% |
| FrontierCode | — | 49.3% |
| LMArena WebDev | — | 1688 |
| SciCode | — | 57.6% |
| LMArena Coding | — | 1447 |
| ALE-Bench | — | 2,462 |
Agentic & Tool Use Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 37.2 (#36)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| APEX-Agents | — | 54.3% |
| GDP.pdf | — | 26.4% |
| Vending-Bench 2 | — | 14,428 |
Reasoning Too close to call
GPT-5.5 Pro: 73.3 (#10), GPT-6 Sol: 74.0 (#9)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| ARC-AGI-2 | 84.6% | 89.6% |
| ARC-AGI-1 | 96.5% | 95.5% |
| CritPt | 30.6% | 30.9% |
| DTBench | 96% | 97.3% |
| LMCA | 53.9% | 59.1% |
| Epoch Capabilities Index | 162.07 | 162.72 |
| SimpleBench | 76.9% | — |
| NYT Connections (extended) | — | 90.1% |
| Chess Puzzles | 64% | — |
| EBR-Bench | — | 53.3% |
| LMArena Hard Prompts | — | 1418 |
| Mystery Game Puzzles | — | 56% |
Math GPT-6 Sol leads
GPT-5.5 Pro: 84.0 (#10), GPT-6 Sol: 87.2 (#7)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | 89.8% |
| FrontierMath Tier 4 | 78% | 90% |
| OTIS Mock AIME 2024-2025 | 100% | 100% |
| ProofBench | — | 83% |
| LMArena Math | — | 1402 |
| FrontierMath (Feb 2025 set) | 52.4% | — |
| FrontierMath Tier 4 (v1) | 39.6% | — |
Knowledge Too close to call
GPT-5.5 Pro: 64.1 (#19), GPT-6 Sol: 64.8 (#15)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| GPQA Diamond | 93.9% | 94.3% |
| SimpleQA Verified | — | 60.7% |
| Vectara Hallucination Rate | — | 6.5% |
| LMArena Expert | — | 1439 |
Multimodal Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 47.6 (#10)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| LMArena Vision | — | 1245 |
| Blueprint-Bench 2 | — | 36.9% |
| Furniture Assembly | — | 58.3% |
Multilingual Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 50.5 (#118)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| LMArena Non-English | — | 1385 |
| LMArena Chinese | — | 1405 |
| LMArena French | — | 1410 |
| LMArena German | — | 1390 |
| LMArena Japanese | — | 1385 |
| LMArena Korean | — | 1341 |
| LMArena Russian | — | 1401 |
| LMArena Spanish | — | 1384 |
Instruction Following Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 74.5 (#94)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| LMArena Instruction Following | — | 1412 |
Long Context Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 43.1 (#108)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| LMArena Longer Query | — | 1411 |
Writing & Preference Not comparable
GPT-5.5 Pro: —, GPT-6 Sol: 71.9 (#18)
| Benchmark | GPT-5.5 Pro | GPT-6 Sol |
|---|---|---|
| LMArena Text | — | 1395 |
| LMArena Creative Writing | — | 1378 |
| EQ-Bench Creative Writing | — | 2125 |
| LMArena Multi-Turn | — | 1412 |
Frequently asked questions
Is GPT-5.5 Pro better than GPT-6 Sol?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 61.8 on the Noometry Index. GPT-6 Sol costs 17× 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-6 Sol?
GPT-6 Sol is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; GPT-5.5 Pro lists at $30 and $180.
Which has the bigger context window?
Both accept 1.05M tokens.
How many benchmarks do GPT-5.5 Pro and GPT-6 Sol share?
10 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and GPT-6 Sol has 45.