# Chatgpt 4o Latest 20250326 vs gpt-oss-20b

> Chatgpt 4o Latest 20250326 is the stronger model overall, scoring 43.2 to 32.1 on the Noometry Index.

- Canonical page: https://noometry.com/compare/chatgpt-4o-vs-gpt-oss-20b
- Last updated: 2026-10-10
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. Chatgpt 4o Latest 20250326 scores higher in 7 categories and gpt-oss-20b in 1 category; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Chatgpt 4o Latest 20250326 leads 62.8 to 35.8.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 75% for Chatgpt 4o Latest 20250326 and 53.2% for gpt-oss-20b.
- gpt-oss-20b has downloadable open weights; the other is API-only.

## Snapshot

| | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 43.2 | 32.1 |
| Rank | 84 | 249 |
| Context | — | 131K |
| Input $/M | — | $0.018 |
| Output $/M | — | $0.09 |
| Weights | Proprietary | Open |

## Coding

- Chatgpt 4o Latest 20250326: 41.0 (#122)
- gpt-oss-20b: 37.1 (#185)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Coding | 1413 | 1307 |
| SciCode | — | 34.4% |
| WeirdML | — | 40.9% |
| ALE-Bench | — | 566.05 |

## Agentic & Tool Use

- Chatgpt 4o Latest 20250326: —
- gpt-oss-20b: 9.2 (#146)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| Terminal-Bench | — | 3.4% |

## Reasoning

- Chatgpt 4o Latest 20250326: 32.8 (#64)
- gpt-oss-20b: 18.8 (#251)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| Kagi LLM Benchmark | 75% | 53.2% |
| LMArena Hard Prompts | 1424 | 1274 |
| CritPt | — | 1.4% |
| Chess Puzzles | — | 4% |
| DTBench | — | 68% |
| LMCA | — | 14.5% |
| Epoch Capabilities Index | — | 137.81 |

## Math

- Chatgpt 4o Latest 20250326: 35.8 (#134)
- gpt-oss-20b: 37.6 (#93)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Math | 1407 | 1317 |
| OTIS Mock AIME 2024-2025 | — | 65.3% |
| Omni-MATH | — | 56.5% |

## Knowledge

- Chatgpt 4o Latest 20250326: 38.7 (#131)
- gpt-oss-20b: 34.6 (#186)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Expert | 1400 | 1258 |
| GPQA Diamond | — | 60.8% |
| MMLU-Pro | — | 74% |
| Confabulations | 16.6% | — |
| GPQA (HELM) | — | 59.4% |

## Multimodal

- Chatgpt 4o Latest 20250326: 38.9 (#54)
- gpt-oss-20b: —

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Vision | 1243 | — |

## Multilingual

- Chatgpt 4o Latest 20250326: 53.1 (#72)
- gpt-oss-20b: 42.4 (#192)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Non-English | 1419 | 1269 |
| LMArena Chinese | 1456 | 1311 |
| LMArena German | 1424 | 1249 |
| LMArena Japanese | 1406 | 1245 |
| LMArena Korean | 1397 | 1239 |
| LMArena Russian | 1429 | 1279 |
| LMArena Spanish | 1435 | 1267 |
| LMArena French | 1447 | — |

## Instruction Following

- Chatgpt 4o Latest 20250326: 74.2 (#102)
- gpt-oss-20b: 62.0 (#235)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Instruction Following | 1403 | 1236 |
| IFEval | — | 73.2% |

## Long Context

- Chatgpt 4o Latest 20250326: 43.1 (#104)
- gpt-oss-20b: 37.9 (#203)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Longer Query | 1413 | 1251 |

## Writing & Preference

- Chatgpt 4o Latest 20250326: 62.8 (#68)
- gpt-oss-20b: 35.8 (#260)

| Benchmark | Chatgpt 4o Latest 20250326 | gpt-oss-20b |
|---|---|---|
| LMArena Text | 1429 | 1288 |
| LMArena Creative Writing | 1406 | 1201 |
| EQ-Bench Creative Writing | 1501 | 666 |
| LMArena Multi-Turn | 1454 | 1268 |
| WildBench | — | 73.7% |

## FAQ

### Is Chatgpt 4o Latest 20250326 better than gpt-oss-20b?

Chatgpt 4o Latest 20250326 is the stronger model overall, scoring 43.2 to 32.1 on the Noometry Index.

### Is Chatgpt 4o Latest 20250326 or gpt-oss-20b better for coding?

Chatgpt 4o Latest 20250326 scores higher on coding benchmarks: 41.0 versus 37.1 in the Noometry coding category.

### How many benchmarks do Chatgpt 4o Latest 20250326 and gpt-oss-20b share?

18 benchmarks have published results for both models. Chatgpt 4o Latest 20250326 has 21 scored results on Noometry and gpt-oss-20b has 34.