# GPT-OSS 120B vs Grok 4.3

> Side-by-side benchmark comparison for GPT-OSS 120B and Grok 4.3 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-oss-120b-vs-grok-4-3
- Last updated: September 10, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-OSS 120B and Grok 4.3 share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- GPT-OSS 120B has the lower published output-token price.
- Grok 4.3 has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-OSS 120B | Grok 4.3 |
|----------|----------|----------|
| Creator | OpenAI | xAI |
| Type | Open Weight | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | 45.69 | 59.73 |
| Benchmarks Covered | 2 | 7 |
| Pricing (input/output) | $0.00 / $0.00 | $1.25 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: 40.8 (Estimated · #113/152)
- Grok 4.3 public-lane score: 26.9 (Supported · #144/152)

| Benchmark | GPT-OSS 120B | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 29.61% | 43.86% | Grok 4.3 |
| ResearchClawBench | Coming soon | 12.4% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 41.9% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: 43.5 (Estimated · #100/151)
- Grok 4.3 public-lane score: 33.6 (Supported · #131/151)

| Benchmark | GPT-OSS 120B | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| React Native Evals | 71.6% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 84.5% | Coming soon |
| SWE-bench (Vals) | Coming soon | 71.4% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: Coming soon
- Grok 4.3 public-lane score: 65.6 (#25/48)

### Reasoning

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: 56.8 (Unranked · 2 rankable rows)
- Grok 4.3 public-lane score: 65.2 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: 42.2 (Estimated · #121/183)
- Grok 4.3 public-lane score: 57 (Supported · #44/183)

| Benchmark | GPT-OSS 120B | Grok 4.3 | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | Coming soon | 91.4% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 85.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-OSS 120B public-lane score: 84.3 (#47/123)
- Grok 4.3 public-lane score: 94.4 (#2/123)

## FAQ

### Is there enough evidence to pick between GPT-OSS 120B and Grok 4.3?

Not yet. The models share only 1 sourced benchmark row, 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 120B vs GPT-OSS 20B](/compare/gpt-oss-120b-vs-gpt-oss-20b)
- [Grok 4.3 vs GPT-OSS 20B](/compare/gpt-oss-20b-vs-grok-4-3)
- [GPT-OSS 120B vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gpt-oss-120b)
- [Grok 4.3 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-grok-4-3)

## Explore More

- [GPT-OSS 120B profile](/models/gpt-oss-120b)
- [Grok 4.3 profile](/models/grok-4-3)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)