# GPT-5.5 Pro vs Ornith-1.5-397B

> Side-by-side benchmark comparison for GPT-5.5 Pro and Ornith-1.5-397B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-pro-vs-ornith-1-5-397b
- Last updated: September 18, 2026

- Shared sourced benchmarks: 3
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.5 Pro and Ornith-1.5-397B share only 3 sourced benchmark rows.

## Summary

- Only 3 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Ornith-1.5-397B has the lower published output-token price.
- GPT-5.5 Pro has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-5.5 Pro | Ornith-1.5-397B |
|----------|----------|----------|
| Creator | OpenAI | Ornith AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 262K |
| Independent public score (not head-to-head) | 61.9 | 65.32 |
| Benchmarks Covered | 6 | 18 |
| Pricing (input/output) | $30.00 / $180.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 58.9 (Estimated · #28/154)
- Ornith-1.5-397B public-lane score: 60.9 (Estimated · #17/154)

| Benchmark | GPT-5.5 Pro | Ornith-1.5-397B | Winner |
|-----------|-----------|-----------|--------|
| BrowseComp | 90.1% | 86.6% | GPT-5.5 Pro |
| Terminal-Bench 2.1 | Coming soon | 86.1% | Coming soon |
| HLE w/ tools | Coming soon | 56.1% | Coming soon |
| MCP Atlas | Coming soon | 80% | Coming soon |
| Toolathlon-Verified | Coming soon | 71.2% | Coming soon |
| WideResearch | Coming soon | 80.8% | Coming soon |
| Claw-Eval | Coming soon | 81.4% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Ornith-1.5-397B public-lane score: 59 (Estimated · #25/154)

| Benchmark | GPT-5.5 Pro | Ornith-1.5-397B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | Coming soon | 86.1% | Coming soon |
| SWE-bench Verified | Coming soon | 86% | Coming soon |
| SWE-bench Pro | Coming soon | 65.1% | Coming soon |
| SWE Multilingual | Coming soon | 79.6% | Coming soon |
| DeepSWE | Coming soon | 56.0% | Coming soon |
| frontierBench | Coming soon | 13.5% | Coming soon |
| NL2Repo | Coming soon | 59.5% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 59.4 (Estimated · #38/184)
- Ornith-1.5-397B public-lane score: 60.5 (Estimated · #35/184)

| Benchmark | GPT-5.5 Pro | Ornith-1.5-397B | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.2% | 44.6% | GPT-5.5 Pro |
| HLE w/o tools | 43.1% | 44.6% | Ornith-1.5-397B |
| GPQA | Coming soon | 92.8% | Coming soon |
| GPQA-D | Coming soon | 92.8% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 70.1 (Unranked · 3 rankable rows)
- Ornith-1.5-397B public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Ornith-1.5-397B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 52.4% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 51.000% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 39.600% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.5 Pro and Ornith-1.5-397B?

Not yet. The models share only 3 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-5.5 Pro vs GPT-5.5](/compare/gpt-5-5-vs-gpt-5-5-pro)
- [Ornith-1.5-397B vs GPT-5.5](/compare/gpt-5-5-vs-ornith-1-5-397b)
- [GPT-5.5 Pro vs Ornith-1.5-35B-A3B](/compare/gpt-5-5-pro-vs-ornith-1-5-35b-a3b)
- [Ornith-1.5-397B vs Ornith-1.5-35B-A3B](/compare/ornith-1-5-35b-a3b-vs-ornith-1-5-397b)

## Explore More

- [GPT-5.5 Pro profile](/models/gpt-5-5-pro)
- [Ornith-1.5-397B profile](/models/ornith-1-5-397b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)