# Claude 4 Sonnet vs GPT-OSS 20B

> Side-by-side benchmark comparison for Claude 4 Sonnet and GPT-OSS 20B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-4-sonnet-vs-gpt-oss-20b
- Last updated: October 17, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude 4 Sonnet and GPT-OSS 20B 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.
- GPT-OSS 20B has the lower published output-token price.
- Claude 4 Sonnet has the larger published context window at 200K.

## Model Snapshot

| Property | Claude 4 Sonnet | GPT-OSS 20B |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Non-Reasoning |
| Context | 200K | 128K |
| Independent public score (not head-to-head) | 38.08 | 33.32 |
| Benchmarks Covered | 4 | 7 |
| Pricing (input/output) | $3.00 / $15.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: Coming soon
- GPT-OSS 20B public-lane score: 14.9 (Estimated · #115/128)

| Benchmark | Claude 4 Sonnet | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 39.66% | Coming soon | Coming soon |
| JobBench | 18.4% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: Coming soon
- GPT-OSS 20B public-lane score: 18.2 (Estimated · #123/150)

| Benchmark | Claude 4 Sonnet | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 72.7% | 60.7% | Claude 4 Sonnet |
| React Native Evals | Coming soon | 71% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: 56.1 (Unranked · 2 rankable rows)
- GPT-OSS 20B public-lane score: 49.7 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: 56.4 (Unranked · 1 rankable row)
- GPT-OSS 20B public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: 37.7 (Estimated · #124/184)
- GPT-OSS 20B public-lane score: 33.9 (Supported · #140/184)

| Benchmark | Claude 4 Sonnet | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| MMLU | Coming soon | 85.3% | Coming soon |
| GPQA | Coming soon | 71.5% | Coming soon |
| HLE | Coming soon | 10.9% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: 53.5 (#86/148)
- GPT-OSS 20B public-lane score: 79.2 (#60/148)

### Mathematics

- Winner: Insufficient shared evidence
- Claude 4 Sonnet public-lane score: Coming soon
- GPT-OSS 20B public-lane score: Coming soon

| Benchmark | Claude 4 Sonnet | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | 33.1% | 91.7% | GPT-OSS 20B |
| AIME 2024 | Coming soon | 92.1% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude 4 Sonnet and GPT-OSS 20B?

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

- [Claude 4 Sonnet vs GPT-OSS 120B](/compare/claude-4-sonnet-vs-gpt-oss-120b)
- [GPT-OSS 20B vs GPT-OSS 120B](/compare/gpt-oss-120b-vs-gpt-oss-20b)
- [Claude 4 Sonnet vs Claude Opus 5.5](/compare/claude-4-sonnet-vs-claude-opus-5-5)
- [GPT-OSS 20B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-oss-20b)

## Explore More

- [Claude 4 Sonnet profile](/models/claude-4-sonnet)
- [GPT-OSS 20B profile](/models/gpt-oss-20b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)