# GPT-5.3 Chat vs o3-pro

> GPT-5.3 Chat and o3-pro score almost the same on the Noometry Index (42.8 vs 42.9), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-o3-pro
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in long context, where o3-pro leads 72.2 to 42.6.
- GPT-5.3 Chat is cheaper at $1.75 / $14 per million input/output tokens, against $20 / $80 for o3-pro.
- o3-pro accepts more context: 200K tokens versus 128K.

## Snapshot

| | GPT-5.3 Chat | o3-pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 42.8 | 42.9 |
| Rank | 109 | 105 |
| Context | 128K | 200K |
| Input $/M | $1.75 | $20 |
| Output $/M | $14 | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Chat: 41.4 (#124)
- o3-pro: 55.5 (#24)

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| WeirdML | — | 58.2% |
| LMArena Coding | 1408 | — |

## Reasoning

- GPT-5.3 Chat: 28.5 (#102)
- o3-pro: 23.8 (#171)

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| ARC-AGI-2 | — | 4.9% |
| Kagi LLM Benchmark | — | 72.1% |
| ARC-AGI-1 | — | 59.3% |
| LMArena Hard Prompts | 1399 | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
| Epoch Capabilities Index | — | 147.42 |

## Math

- GPT-5.3 Chat: 38.2 (#142)
- o3-pro: —

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| LMArena Math | 1389 | — |

## Knowledge

- GPT-5.3 Chat: 38.8 (#140)
- o3-pro: 29.5 (#238)

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
| LMArena Expert | 1397 | — |

## Multilingual

- GPT-5.3 Chat: 50.3 (#124)
- o3-pro: —

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| LMArena Non-English | 1382 | — |
| LMArena Chinese | 1432 | — |
| LMArena French | 1397 | — |
| LMArena German | 1384 | — |
| LMArena Japanese | 1352 | — |
| LMArena Korean | 1346 | — |
| LMArena Russian | 1400 | — |
| LMArena Spanish | 1371 | — |

## Instruction Following

- GPT-5.3 Chat: 72.8 (#129)
- o3-pro: —

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1378 | — |

## Long Context

- GPT-5.3 Chat: 42.6 (#120)
- o3-pro: 72.2 (#1)

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1396 | — |

## Writing & Preference

- GPT-5.3 Chat: 63.1 (#68)
- o3-pro: 57.1 (#133)

| Benchmark | GPT-5.3 Chat | o3-pro |
|---|---|---|
| LMArena Text | 1389 | — |
| LMArena Creative Writing | 1355 | — |
| Short-Story Creative Writing | — | 84.4% |
| EQ-Bench Creative Writing | 1690 | — |
| LMArena Multi-Turn | 1412 | — |

## FAQ

### Is GPT-5.3 Chat better than o3-pro?

GPT-5.3 Chat and o3-pro score almost the same on the Noometry Index (42.8 vs 42.9), so choose on price, context window or the category you care about most.

### Which is cheaper, GPT-5.3 Chat or o3-pro?

GPT-5.3 Chat is cheaper. It lists at $1.75 per million input tokens and $14 per million output tokens; o3-pro lists at $20 and $80.

### Is GPT-5.3 Chat or o3-pro better for coding?

o3-pro scores higher on coding benchmarks: 55.5 versus 41.4 in the Noometry coding category.

### Which has the bigger context window?

o3-pro does, with 200K tokens against 128K.

### How many benchmarks do GPT-5.3 Chat and o3-pro share?

0 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and o3-pro has 12.