# GPT-4o vs GPT-OSS 20B

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

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

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for GPT-4o and GPT-OSS 20B.

## Summary

- GPT-4o and GPT-OSS 20B do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | GPT-4o | GPT-OSS 20B |
|----------|----------|----------|
| Creator | OpenAI | OpenAI |
| Type | Proprietary | Open Weight |
| Reasoning | Non-Reasoning | Non-Reasoning |
| Context | 128K | 128K |
| Independent public score (not head-to-head) | 29.92 | 33.32 |
| Benchmarks Covered | 2 | 7 |
| Pricing (input/output) | $2.50 / $10.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

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

### Coding

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

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

### Reasoning

- Winner: Insufficient shared evidence
- GPT-4o public-lane score: 59.7 (Unranked · 2 rankable rows)
- GPT-OSS 20B public-lane score: 49.7 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- GPT-4o public-lane score: 27.9 (Estimated · #162/184)
- GPT-OSS 20B public-lane score: 33.9 (Supported · #140/184)

| Benchmark | GPT-4o | 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 |

### Multilingual

- Winner: Insufficient shared evidence
- GPT-4o public-lane score: 30.2 (#16/17)
- GPT-OSS 20B public-lane score: Coming soon

| Benchmark | GPT-4o | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | 61.1% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-4o public-lane score: 39 (#121/148)
- GPT-OSS 20B public-lane score: 79.2 (#60/148)

### Mathematics

- Winner: Insufficient shared evidence
- GPT-4o public-lane score: 27 (Unranked · 1 rankable row)
- GPT-OSS 20B public-lane score: Coming soon

| Benchmark | GPT-4o | GPT-OSS 20B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 0.351% | Coming soon | Coming soon |
| AIME 2024 | Coming soon | 92.1% | Coming soon |
| AIME 2025 | Coming soon | 91.7% | Coming soon |

## FAQ

### Can I compare GPT-4o and GPT-OSS 20B on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [GPT-4o vs GPT-4o mini](/compare/gpt-4o-vs-gpt-4o-mini)
- [GPT-OSS 20B vs GPT-4o mini](/compare/gpt-4o-mini-vs-gpt-oss-20b)
- [GPT-4o vs GPT-OSS 120B](/compare/gpt-4o-vs-gpt-oss-120b)
- [GPT-OSS 20B vs GPT-OSS 120B](/compare/gpt-oss-120b-vs-gpt-oss-20b)

## Explore More

- [GPT-4o profile](/models/gpt-4o)
- [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)