# Claude Sonnet 5.5 vs GPT-6.1 Terra

> Side-by-side benchmark comparison for Claude Sonnet 5.5 and GPT-6.1 Terra across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-5-vs-gpt-6-1-terra
- Last updated: October 26, 2026

- Shared sourced benchmarks: 7
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Claude Sonnet 5.5 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Claude Sonnet 5.5 has the higher overall point estimate 82.21 to 75.87. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in knowledge, where the averages are 82.1 for Claude Sonnet 5.5 and 74.9 for GPT-6.1 Terra.
- The biggest single benchmark swing is Terminal-Bench 4.0 in Agentic, with scores of 70.60% and 50.30%.
- GPT-6.1 Terra is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- GPT-6.1 Terra also has the larger context window at 1.05M.

## Model Snapshot

| Property | Claude Sonnet 5.5 | GPT-6.1 Terra |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1.05M |
| Overall Score | 82.21 | 75.87 |
| Benchmarks Covered | 58 | 10 |
| Pricing (input/output) | $2.00 / $10.00 | $1.00 / $5.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 68.8 (Supported · #11/133)
- GPT-6.1 Terra public-lane score: 72.4 (Estimated · #8/133)

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 70.60% | 50.30% | Claude Sonnet 5.5 |
| HLE w/ tools | 64.5% | Coming soon | Coming soon |
| DRACO | 87.0% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 59.9% | 58.3% | Claude Sonnet 5.5 |
| LAB all-pass (Harvey held-out) | 10.0% | Coming soon | Coming soon |
| LAB criterion-pass (Harvey held-out) | 93.1% | Coming soon | Coming soon |
| Toolathlon Verified Pass@3 | 85.2% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 68.5% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 31.6 turns | Coming soon | Coming soon |
| AutomationBench (Zapier 1.0.6) | 44.70% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | Coming soon | Coming soon |
| Hermes Index | 53.1% | Coming soon | Coming soon |
| Hermes Bench | 73.5% | Coming soon | Coming soon |
| MazeBench | 8% | Coming soon | Coming soon |
| OSWorld 2.1 | 80.1% | Coming soon | Coming soon |
| OSWorld 2.1 Offline | 83.9% | 74.2% | Claude Sonnet 5.5 |
| Agents' Last Exam | Coming soon | 60.0% | Coming soon |

### Coding

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 84.5 (Supported · #1/154)
- GPT-6.1 Terra public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 46.2% | Coming soon | Coming soon |
| CursorBench 4.0 | 55.5% | Coming soon | Coming soon |
| SWE-bench Pro | 81.3% | Coming soon | Coming soon |
| SWE Multilingual | 90.3% | Coming soon | Coming soon |
| SWE Multimodal | 54.3% | Coming soon | Coming soon |
| DeepSWE | 71.0% | Coming soon | Coming soon |
| FrontierCode 1.1 Extended | 59.1% | Coming soon | Coming soon |
| ProgramBench | 79.7% | Coming soon | Coming soon |
| FrontierSWE v2 | 61.9% | Coming soon | Coming soon |
| Bug Hunt Bench | 51.3 fixes | Coming soon | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 81.8 (#6/26)
- GPT-6.1 Terra public-lane score: 81.8 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 85.1 (Unranked · 7 rankable rows)
- GPT-6.1 Terra public-lane score: 91.6 (#4/58)

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| ExtractBench Pro | 32% | Coming soon | Coming soon |
| ExtractBench (LlamaIndex) | 94.68% | Coming soon | Coming soon |
| ParseBench | 69.26% | Coming soon | Coming soon |
| Chartography (no tools) | 61.6% | Coming soon | Coming soon |
| Chartography (tools) | 90.2% | Coming soon | Coming soon |
| BenchCAD Vision2Code (no tools) | 0.747 | Coming soon | Coming soon |
| BenchCAD Vision2Code (tools) | 0.963 | Coming soon | Coming soon |
| Biomedical image analysis | 72.2% | Coming soon | Coming soon |
| OfficeQA | 76.9% | Coming soon | Coming soon |
| OfficeQA Pro | 65.6% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 85.5% | Coming soon |

### Knowledge

- Winner: Claude Sonnet 5.5
- Claude Sonnet 5.5 public-lane score: 82.1 (Supported · #6/188)
- GPT-6.1 Terra public-lane score: 74.9 (Supported · #12/188)

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| HealthBench (raw) | 69.4% | 51.1% | Claude Sonnet 5.5 |
| HealthBench (length-adjusted) | 65.4% | 55.1% | Claude Sonnet 5.5 |
| HealthBench Professional (raw) | 77.1% | 64.2% | Claude Sonnet 5.5 |
| HealthBench Professional | 69.2% | 62.7% | Claude Sonnet 5.5 |
| BioMysteryBench (human-solvable) | 89.2% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 44.7% | Coming soon | Coming soon |
| SpatialBench Verified | 72.5% | Coming soon | Coming soon |
| SingleCellBench | 59.1% | Coming soon | Coming soon |
| Protein Design | 51.0% | Coming soon | Coming soon |
| Morphology-to-molecule matching | 25.0% | Coming soon | Coming soon |
| Medicinal chemistry | 65.3% | Coming soon | Coming soon |
| Protein Design library ranking | 54.8% | Coming soon | Coming soon |
| De novo protein-binder design | 82.3% | Coming soon | Coming soon |
| Protocols (troubleshooting) | 67.3% | Coming soon | Coming soon |
| Protocols (understanding) | 66.6% | Coming soon | Coming soon |
| HLE w/o tools | 56.9% | Coming soon | Coming soon |
| HealthBench Hard | Coming soon | 31.4% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: Coming soon
- GPT-6.1 Terra public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | 92.1% | Coming soon | Coming soon |
| MILU | 91.6% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 95.2 (Unranked · 4 rankable rows)
- GPT-6.1 Terra public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | GPT-6.1 Terra | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | 86.8% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (tools) | 95.2% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 88.772% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 80.488% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 5.5 or GPT-6.1 Terra?

Claude Sonnet 5.5 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Claude Sonnet 5.5 and GPT-6.1 Terra?

The widest category gap is in knowledge, where the averages are 82.1 for Claude Sonnet 5.5 and 74.9 for GPT-6.1 Terra.

### How many benchmarks does Claude Sonnet 5.5 cover on BenchLM?

Claude Sonnet 5.5 currently has 58 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-6.1 Terra cover on BenchLM?

GPT-6.1 Terra currently has 10 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5.5 vs GPT-6 Astra](/compare/claude-sonnet-5-5-vs-gpt-6-astra)
- [GPT-6.1 Terra vs GPT-6 Astra](/compare/gpt-6-1-terra-vs-gpt-6-astra)
- [Claude Sonnet 5.5 vs GPT-6.1 Sol](/compare/claude-sonnet-5-5-vs-gpt-6-1-sol)
- [GPT-6.1 Terra vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-gpt-6-1-terra)

## Explore More

- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [GPT-6.1 Terra profile](/models/gpt-6-1-terra)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)