# Gemini 2.5 Pro vs GPT-5.3 Codex

> Gemini 2.5 Pro and GPT-5.3 Codex score almost the same on the Noometry Index (45.0 vs 45.8), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gemini-2-5-pro-vs-gpt-5-3-codex
- Last updated: 2026-10-10
- Shared benchmarks: 8

## Summary

- They share 8 benchmarks with published results for both. Gemini 2.5 Pro scores higher in 0 categories and GPT-5.3 Codex in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 29.2.
- The biggest single-benchmark swing is Terminal-Bench: 32.6% for Gemini 2.5 Pro and 78.4% for GPT-5.3 Codex.
- Gemini 2.5 Pro is cheaper at $1.25 / $10 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- Gemini 2.5 Pro accepts more context: 1.05M tokens versus 400K.

## Snapshot

| | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 45.0 | 45.8 |
| Rank | 75 | 69 |
| Context | 1.05M | 400K |
| Input $/M | $1.25 | $1.75 |
| Output $/M | $10 | $14 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 2.5 Pro: 42.4 (#101)
- GPT-5.3 Codex: 48.6 (#56)

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| SWE-bench Verified | 57.6% | 74.8% |
| LMArena WebDev | 1227 | 1409 |
| WeirdML | 54% | 79.3% |
| ALE-Bench | 785.52 | 1,655 |
| SWE-bench Verified (bash only) | 53.6% | — |
| Aider Polyglot | 83.1% | — |
| SciCode | 42.8% | — |
| GSO | 3.9% | — |
| LiveBench Coding | 85.9% | — |
| LMArena Coding | 1452 | — |
| CadEval | 64% | — |
| AlgoTune | 1.51 | — |

## Agentic & Tool Use

- Gemini 2.5 Pro: 29.2 (#88)
- GPT-5.3 Codex: 48.0 (#9)

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| Terminal-Bench | 32.6% | 78.4% |
| METR Time Horizons | 55.4% | 74.5% |
| Vending-Bench 2 | 573.64 | 5,940 |
| GDPval | 23.3% | — |
| Remote Labor Index | 0.8% | — |
| TheAgentCompany | 30.3% | — |
| τ²-bench Banking | 13.7% | — |
| DeepResearch Bench | 42.8% | — |
| BALROG | 43.3% | — |
| LMArena Search | 1142 | — |

## Reasoning

- Gemini 2.5 Pro: 28.8 (#99)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| Epoch Capabilities Index | 145.32 | 156.77 |
| ARC-AGI-2 | 4.9% | — |
| SimpleBench | 62.4% | — |
| Kagi LLM Benchmark | 70.3% | — |
| ARC-AGI-1 | 41% | — |
| CritPt | 2% | — |
| Chess Puzzles | 20% | — |
| EnigmaEval | 5.6% | — |
| LiveBench Reasoning | 89.8% | — |
| LMArena Hard Prompts | 1455 | — |
| DTBench | 82.4% | — |
| LiveBench Data Analysis | 79.9% | — |
| LMCA | 34.8% | — |
| ForecastBench | 61.3 | — |
| LiveBench | 82.3% | — |

## Math

- Gemini 2.5 Pro: 32.5 (#213)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| FrontierMath (Tiers 1-3) | 24.6% | — |
| FrontierMath Tier 4 | 0% | — |
| OTIS Mock AIME 2024-2025 | 84.7% | — |
| Omni-MATH | 41.6% | — |
| LiveBench Math | 90.2% | — |
| LMArena Math | 1450 | — |
| MATH Level 5 | 95.9% | — |
| FrontierMath (Feb 2025 set) | 14.1% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Gemini 2.5 Pro: 56.0 (#46)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| GPQA Diamond | 85.3% | — |
| Humanity's Last Exam | 21.6% | — |
| MMLU-Pro | 86.3% | — |
| Confabulations | 10.6% | — |
| Vectara Hallucination Rate | 7% | — |
| GPQA (HELM) | 74.9% | — |
| LMArena Expert | 1452 | — |

## Multimodal

- Gemini 2.5 Pro: 45.2 (#18)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| LMArena Vision | 1263 | — |
| GeoBench | 86% | — |
| VPCT | 48% | — |
| LMArena Document | 1421 | — |
| SpatialViz-Bench | 44.7% | — |

## Multilingual

- Gemini 2.5 Pro: 55.3 (#31)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| LMArena Non-English | 1451 | — |
| LMArena Chinese | 1507 | — |
| LMArena French | 1472 | — |
| LMArena German | 1487 | — |
| LMArena Japanese | 1461 | — |
| LMArena Korean | 1434 | — |
| LMArena Russian | 1461 | — |
| LMArena Spanish | 1473 | — |

## Instruction Following

- Gemini 2.5 Pro: 75.0 (#75)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| LiveBench Instruction Following | 80.6% | — |
| IFEval | 84% | — |
| LMArena Instruction Following | 1437 | — |

## Long Context

- Gemini 2.5 Pro: 59.8 (#5)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| Fiction.LiveBench | 91.7% | — |
| LMArena Longer Query | 1449 | — |

## Writing & Preference

- Gemini 2.5 Pro: 63.7 (#62)
- GPT-5.3 Codex: —

| Benchmark | Gemini 2.5 Pro | GPT-5.3 Codex |
|---|---|---|
| LMArena Text | 1458 | — |
| LMArena Creative Writing | 1454 | — |
| Short-Story Creative Writing | 83.8% | — |
| EQ-Bench Creative Writing | 1421 | — |
| WildBench | 85.7% | — |
| LMArena Multi-Turn | 1453 | — |
| LiveBench Language | 67.8% | — |

## FAQ

### Is Gemini 2.5 Pro better than GPT-5.3 Codex?

Gemini 2.5 Pro and GPT-5.3 Codex score almost the same on the Noometry Index (45.0 vs 45.8), so choose on price, context window or the category you care about most.

### Which is cheaper, Gemini 2.5 Pro or GPT-5.3 Codex?

Gemini 2.5 Pro is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is Gemini 2.5 Pro or GPT-5.3 Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 42.4 in the Noometry coding category.

### Which has the bigger context window?

Gemini 2.5 Pro does, with 1.05M tokens against 400K.

### How many benchmarks do Gemini 2.5 Pro and GPT-5.3 Codex share?

8 benchmarks have published results for both models. Gemini 2.5 Pro has 78 scored results on Noometry and GPT-5.3 Codex has 8.