# GPT-5.3 Codex vs Yi-1.5-34B

> GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 30.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-yi-1-5-34b
- Last updated: 2026-10-12
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 32.4.
- Yi-1.5-34B has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| Provider | OpenAI | 01.AI |
| Noometry Index | 45.8 | 30.6 |
| Rank | 69 | 289 |
| Context | 400K | — |
| Input $/M | $1.75 | — |
| Output $/M | $14 | — |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- Yi-1.5-34B: 32.4 (#272)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| WeirdML | 79.3% | — |
| BigCodeBench Instruct | — | 33.9% |
| LMArena Coding | — | 1169 |
| BigCodeBench Complete | — | 43.8% |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- Yi-1.5-34B: —

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Yi-1.5-34B: 22.5 (#191)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Hard Prompts | — | 1160 |
| Epoch Capabilities Index | 156.77 | — |

## Math

- GPT-5.3 Codex: —
- Yi-1.5-34B: 27.5 (#249)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Math | — | 1182 |
| MATH Level 5 | — | 25.5% |

## Knowledge

- GPT-5.3 Codex: —
- Yi-1.5-34B: 14.8 (#295)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| GPQA Diamond | — | 32% |
| LMArena Expert | — | 1144 |

## Multilingual

- GPT-5.3 Codex: —
- Yi-1.5-34B: 32.3 (#256)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Non-English | — | 1121 |
| LMArena Chinese | — | 1213 |
| LMArena French | — | 1156 |
| LMArena German | — | 1111 |
| LMArena Japanese | — | 1021 |
| LMArena Korean | — | 1005 |
| LMArena Russian | — | 1091 |
| LMArena Spanish | — | 1121 |

## Instruction Following

- GPT-5.3 Codex: —
- Yi-1.5-34B: 59.2 (#257)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Instruction Following | — | 1139 |

## Long Context

- GPT-5.3 Codex: —
- Yi-1.5-34B: 34.6 (#248)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Longer Query | — | 1143 |

## Writing & Preference

- GPT-5.3 Codex: —
- Yi-1.5-34B: 37.4 (#257)

| Benchmark | GPT-5.3 Codex | Yi-1.5-34B |
|---|---|---|
| LMArena Text | — | 1173 |
| LMArena Creative Writing | — | 1135 |
| LMArena Multi-Turn | — | 1153 |

## FAQ

### Is GPT-5.3 Codex better than Yi-1.5-34B?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 30.6 on the Noometry Index.

### Is GPT-5.3 Codex or Yi-1.5-34B better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 32.4 in the Noometry coding category.

### How many benchmarks do GPT-5.3 Codex and Yi-1.5-34B share?

0 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Yi-1.5-34B has 21.