# GPT-5.6 Terra vs Pareto 26.9

> Side-by-side benchmark comparison for GPT-5.6 Terra and Pareto 26.9 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-6-terra-vs-pareto-26-9
- Last updated: September 18, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.6 Terra and Pareto 26.9 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Pareto 26.9 has the lower published output-token price.
- GPT-5.6 Terra has the larger published context window at 1.05M.

## Model Snapshot

| Property | GPT-5.6 Terra | Pareto 26.9 |
|----------|----------|----------|
| Creator | OpenAI | Unbiased |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1.05M | N/A |
| Independent public score (not head-to-head) | 71.13 | null |
| Benchmarks Covered | 33 | 4 |
| Pricing (input/output) | $2.00 / $12.00 | $2.50 / $7.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 60.4 (Supported · #18/154)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 20.8% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 87.4% | Coming soon | Coming soon |
| BrowseComp | 87.5% | Coming soon | Coming soon |
| OSWorld 2.0 | 50.2% | Coming soon | Coming soon |
| CyberGym | 81.8% | Coming soon | Coming soon |
| ExploitGym | 23.2% | Coming soon | Coming soon |
| Toolathlon | 53.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 77.5% | Coming soon | Coming soon |
| ApprenticeBench | 16% | Coming soon | Coming soon |
| Terminal-Bench 4.0 | Coming soon | 51.00% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 67 (Supported · #8/154)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 63.4% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 87.4% | Coming soon | Coming soon |
| DeepSWE | 69.6% | 74.0% | Pareto 26.9 |
| FrontierCode 1.1 Extended | 55.8% | Coming soon | Coming soon |
| cursorBench32 | 64.9% | Coming soon | Coming soon |
| VulcanBench v3 | 87.0% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 85.9% | Coming soon | Coming soon |
| SWE-bench (Vals) | 95.4% | Coming soon | Coming soon |
| cursorBench40 | 41.3% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 77.2 (#15/48)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 80.7% | 78% | GPT-5.6 Terra |
| MMMU-Pro w/ Python | 82% | Coming soon | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 63.7 (#14/20)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 83.9% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.8% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 69.3 (Supported · #15/184)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 92.9% | Coming soon | Coming soon |
| GPQA-D | 92.9% | Coming soon | Coming soon |
| HLE-Verified | 51.1% | Coming soon | Coming soon |
| LABBench2 | 81.2% | Coming soon | Coming soon |
| HealthBench Professional | 57.7% | Coming soon | Coming soon |
| HealthBench Hard | 32.7% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 90.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 86.7% | Coming soon | Coming soon |
| HLE w/o tools | Coming soon | 49% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 85.7 (#35/124)
- Pareto 26.9 public-lane score: Coming soon

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.6 Terra public-lane score: 96.8 (Unranked · 3 rankable rows)
- Pareto 26.9 public-lane score: Coming soon

| Benchmark | GPT-5.6 Terra | Pareto 26.9 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 84.9% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 84.900% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 68.300% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.6 Terra and Pareto 26.9?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-5.6 Terra vs GPT-5.6 Sol](/compare/gpt-5-6-sol-vs-gpt-5-6-terra)
- [Pareto 26.9 vs GPT-5.6 Sol](/compare/gpt-5-6-sol-vs-pareto-26-9)
- [GPT-5.6 Terra vs GPT-5.6 Luna](/compare/gpt-5-6-luna-vs-gpt-5-6-terra)
- [Pareto 26.9 vs GPT-5.6 Luna](/compare/gpt-5-6-luna-vs-pareto-26-9)

## Explore More

- [GPT-5.6 Terra profile](/models/gpt-5-6-terra)
- [Pareto 26.9 profile](/models/pareto-26-9)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)