# GPT-5.6 Terra vs GPT-6 Sol

> GPT-6 Sol is the stronger model overall, scoring 61.8 to 59.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-6-terra-vs-gpt-6-sol
- Last updated: 2026-10-12
- Shared benchmarks: 43

## Summary

- They share 43 benchmarks with published results for both. GPT-5.6 Terra scores higher in 4 categories and GPT-6 Sol in 6 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-6 Sol leads 74.0 to 60.7.
- The biggest single-benchmark swing is Mystery Game Puzzles: 35% for GPT-5.6 Terra and 56% for GPT-6 Sol.
- GPT-6 Sol is cheaper at $2 / $10 per million input/output tokens, against $2 / $12 for GPT-5.6 Terra.

## Snapshot

| | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 59.2 | 61.8 |
| Rank | 17 | 12 |
| Context | 1.05M | 1.05M |
| Input $/M | $2 | $2 |
| Output $/M | $12 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.6 Terra: 57.7 (#19)
- GPT-6 Sol: 60.1 (#11)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| DeepSWE | 69.6% | 68.8% |
| FrontierCode | 41.3% | 49.3% |
| LMArena WebDev | 1522 | 1688 |
| SciCode | 55% | 57.6% |
| LMArena Coding | 1484 | 1447 |
| ALE-Bench | 1,951 | 2,462 |
| CursorBench | 41.3% | — |
| WeirdML | 78.3% | — |

## Agentic & Tool Use

- GPT-5.6 Terra: 40.1 (#25)
- GPT-6 Sol: 37.2 (#36)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| APEX-Agents | 58.2% | 54.3% |
| GDP.pdf | 24.7% | 26.4% |
| Vending-Bench 2 | 7,343 | 14,428 |
| BALROG | 53.2% | — |

## Reasoning

- GPT-5.6 Terra: 60.7 (#21)
- GPT-6 Sol: 74.0 (#9)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| ARC-AGI-2 | 83.9% | 89.6% |
| NYT Connections (extended) | 78.4% | 90.1% |
| ARC-AGI-1 | 96.5% | 95.5% |
| CritPt | 30% | 30.9% |
| LMArena Hard Prompts | 1468 | 1418 |
| Mystery Game Puzzles | 35% | 56% |
| DTBench | 93.3% | 97.3% |
| LMCA | 55% | 59.1% |
| Epoch Capabilities Index | 159.62 | 162.72 |
| SimpleBench | 48.9% | — |
| Kagi LLM Benchmark | 51.3% | — |
| Chess Puzzles | 54% | — |
| EBR-Bench | — | 53.3% |
| Surface Evolver Bench | 83.8% | — |

## Math

- GPT-5.6 Terra: 81.6 (#12)
- GPT-6 Sol: 87.2 (#7)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| FrontierMath (Tiers 1-3) | 86% | 89.8% |
| FrontierMath Tier 4 | 70.7% | 90% |
| OTIS Mock AIME 2024-2025 | 99.7% | 100% |
| ProofBench | 74% | 83% |
| LMArena Math | 1466 | 1402 |

## Knowledge

- GPT-5.6 Terra: 61.2 (#30)
- GPT-6 Sol: 64.8 (#15)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| GPQA Diamond | 93.3% | 94.3% |
| SimpleQA Verified | 43.2% | 60.7% |
| LMArena Expert | 1492 | 1439 |
| Vectara Hallucination Rate | — | 6.5% |

## Multimodal

- GPT-5.6 Terra: 47.3 (#11)
- GPT-6 Sol: 47.6 (#10)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| LMArena Vision | 1271 | 1245 |
| Blueprint-Bench 2 | 30.8% | 36.9% |
| Furniture Assembly | 54.2% | 58.3% |
| LMArena Document | 1472 | — |

## Multilingual

- GPT-5.6 Terra: 54.4 (#44)
- GPT-6 Sol: 50.5 (#118)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| LMArena Non-English | 1439 | 1385 |
| LMArena Chinese | 1513 | 1405 |
| LMArena French | 1471 | 1410 |
| LMArena German | 1460 | 1390 |
| LMArena Japanese | 1457 | 1385 |
| LMArena Korean | 1425 | 1341 |
| LMArena Russian | 1450 | 1401 |
| LMArena Spanish | 1448 | 1384 |

## Instruction Following

- GPT-5.6 Terra: 76.4 (#40)
- GPT-6 Sol: 74.5 (#94)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| LMArena Instruction Following | 1454 | 1412 |

## Long Context

- GPT-5.6 Terra: 44.4 (#68)
- GPT-6 Sol: 43.1 (#108)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| LMArena Longer Query | 1451 | 1411 |

## Writing & Preference

- GPT-5.6 Terra: 70.2 (#23)
- GPT-6 Sol: 71.9 (#18)

| Benchmark | GPT-5.6 Terra | GPT-6 Sol |
|---|---|---|
| LMArena Text | 1447 | 1395 |
| LMArena Creative Writing | 1410 | 1378 |
| EQ-Bench Creative Writing | 1855 | 2125 |
| LMArena Multi-Turn | 1449 | 1412 |
| EQ-Bench 4 | 1234 | — |

## FAQ

### Is GPT-5.6 Terra better than GPT-6 Sol?

GPT-6 Sol is the stronger model overall, scoring 61.8 to 59.2 on the Noometry Index.

### Which is cheaper, GPT-5.6 Terra or GPT-6 Sol?

GPT-6 Sol is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; GPT-5.6 Terra lists at $2 and $12.

### Is GPT-5.6 Terra or GPT-6 Sol better for coding?

GPT-6 Sol scores higher on coding benchmarks: 60.1 versus 57.7 in the Noometry coding category.

### Which has the bigger context window?

Both accept 1.05M tokens.

### How many benchmarks do GPT-5.6 Terra and GPT-6 Sol share?

43 benchmarks have published results for both models. GPT-5.6 Terra has 52 scored results on Noometry and GPT-6 Sol has 45.