# GPT-OSS 20B vs Nemotron 3 Ultra

> Side-by-side benchmark comparison for GPT-OSS 20B and Nemotron 3 Ultra across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-oss-20b-vs-nemotron-3-ultra
- Last updated: October 17, 2026

- Shared sourced benchmarks: 3
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-OSS 20B and Nemotron 3 Ultra 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.
- Nemotron 3 Ultra has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-OSS 20B | Nemotron 3 Ultra |
|----------|----------|----------|
| Creator | OpenAI | NVIDIA |
| Type | Open Weight | Open Weight |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | 33.32 | 46.58 |
| Benchmarks Covered | 7 | 25 |
| Pricing (input/output) | $0.00 / $0.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: 14.9 (Estimated · #115/128)
- Nemotron 3 Ultra public-lane score: 27.7 (Supported · #98/128)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | Coming soon | 56.4% | Coming soon |
| PinchBench | Coming soon | 90.0% | Coming soon |
| BrowseComp | Coming soon | 44.4% | Coming soon |
| τ³-bench results | Coming soon | 70.9% | Coming soon |
| HLE w/ tools | Coming soon | 37.4% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 50.9% | Coming soon |
| MazeBench | Coming soon | 0% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: 18.2 (Estimated · #123/150)
- Nemotron 3 Ultra public-lane score: 21.7 (Supported · #116/150)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 60.7% | 71.9% | Nemotron 3 Ultra |
| React Native Evals | 71% | Coming soon | Coming soon |
| SWE Multilingual | Coming soon | 67.7% | Coming soon |
| LiveCodeBench v6 | Coming soon | 89.0% | Coming soon |
| SciCode | Coming soon | 44.6% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 56.4% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 86.0% | Coming soon |
| SWE-bench (Vals) | Coming soon | 69.0% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: 49.7 (Unranked · 2 rankable rows)
- Nemotron 3 Ultra public-lane score: 70.3 (Unranked · 1 rankable row)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 3.1% | Coming soon |
| LongBench v2 | Coming soon | 61.9% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: 33.9 (Supported · #140/184)
- Nemotron 3 Ultra public-lane score: 50 (Estimated · #81/184)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| MMLU | 85.3% | Coming soon | Coming soon |
| GPQA | 71.5% | 87% | Nemotron 3 Ultra |
| HLE | 10.9% | 26.7% | Nemotron 3 Ultra |
| GPQA-D | Coming soon | 87.0% | Coming soon |
| HLE w/o tools | Coming soon | 26.7% | Coming soon |
| MMLU-Pro | Coming soon | 86.8% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 86.1% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 85.8% | Coming soon |

### Multilingual

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: 89.2 (#7/17)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | Coming soon | 83% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: 79.2 (#60/148)
- Nemotron 3 Ultra public-lane score: 92.1 (#20/148)

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 81.7% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-OSS 20B public-lane score: Coming soon
- Nemotron 3 Ultra public-lane score: Coming soon

| Benchmark | GPT-OSS 20B | Nemotron 3 Ultra | Winner |
|-----------|-----------|-----------|--------|
| AIME 2024 | 92.1% | Coming soon | Coming soon |
| AIME 2025 | 91.7% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-OSS 20B and Nemotron 3 Ultra?

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-OSS 20B vs GPT-OSS 120B](/compare/gpt-oss-120b-vs-gpt-oss-20b)
- [Nemotron 3 Ultra vs GPT-OSS 120B](/compare/gpt-oss-120b-vs-nemotron-3-ultra)
- [GPT-OSS 20B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-oss-20b)
- [Nemotron 3 Ultra vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-nemotron-3-ultra)

## Explore More

- [GPT-OSS 20B profile](/models/gpt-oss-20b)
- [Nemotron 3 Ultra profile](/models/nemotron-3-ultra)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)