# Gemini 3.1 Pro vs GPT-5.3 Codex

> Side-by-side benchmark comparison for Gemini 3.1 Pro and GPT-5.3 Codex across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-1-pro-vs-gpt-5-3-codex
- Last updated: October 17, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Gemini 3.1 Pro leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Gemini 3.1 Pro has the higher overall point estimate 64.7 to 60.48. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in reasoning, where the averages are 58.2 for Gemini 3.1 Pro and 83.1 for GPT-5.3 Codex.
- The biggest single benchmark swing is Vibe Code Bench in Coding, with scores of 32.03% and 61.77%.
- Gemini 3.1 Pro is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Gemini 3.1 Pro also has the larger context window at 1M.

## Model Snapshot

| Property | Gemini 3.1 Pro | GPT-5.3 Codex |
|----------|----------|----------|
| Creator | Google | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 400K |
| Overall Score | 64.7 | 60.48 |
| Benchmarks Covered | 30 | 11 |
| Pricing (input/output) | $2.00 / $12.00 | $1.75 / $14.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Gemini 3.1 Pro public-lane score: 38.4 (Supported · #70/128)
- GPT-5.3 Codex public-lane score: 55.5 (Estimated · #41/128)

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| Claw-Eval | 57.8% | Coming soon | Coming soon |
| DeepSearchQA | 69.7% | Coming soon | Coming soon |
| τ²-bench results | 95.6% | Coming soon | Coming soon |
| Gert Labs | 56.87% | 57.47% | GPT-5.3 Codex |
| ResearchClawBench | 13.3% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 70.8% | Coming soon | Coming soon |
| MazeBench | 1% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 77.3% | Coming soon |
| OSWorld-Verified | Coming soon | 64.7% | Coming soon |
| JobBench | Coming soon | 33.7% | Coming soon |

### Coding

- Winner: GPT-5.3 Codex
- Gemini 3.1 Pro public-lane score: 39.2 (Supported · #67/150)
- GPT-5.3 Codex public-lane score: 53.5 (Supported · #35/150)

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench Pro | 82.9% | Coming soon | Coming soon |
| React Native Evals | 78.9% | Coming soon | Coming soon |
| Vibe Code Bench | 32.03% | 61.77% | GPT-5.3 Codex |
| LiveCodeBench (Vals) | 88.5% | 87.3% | Gemini 3.1 Pro |
| SWE-bench (Vals) | 78.8% | 78.0% | Gemini 3.1 Pro |
| PostTrainBench v1.1 | 22.0% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 85% | Coming soon |
| SWE-bench Pro | Coming soon | 56.8% | Coming soon |
| SWE-Rebench | Coming soon | 58.2% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 77.3% | Coming soon |

### Reasoning

- Winner: Not comparable
- Gemini 3.1 Pro public-lane score: 58.2 (Unranked · 2 rankable rows)
- GPT-5.3 Codex public-lane score: 83.1 (Unranked · 2 rankable rows)

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 77.1% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.4% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Gemini 3.1 Pro public-lane score: 80.1 (#17/54)
- GPT-5.3 Codex public-lane score: 80.1 (Unranked · 1 rankable row)

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 83.9% | Coming soon | Coming soon |
| CharXiv | 80.2% | Coming soon | Coming soon |
| ERQA | 69.4% | Coming soon | Coming soon |
| SimpleVQA | 72.4% | Coming soon | Coming soon |
| ScreenSpot Pro | 84.4% | Coming soon | Coming soon |
| ZeroBench | 29.0% | Coming soon | Coming soon |
| MedXpertQA (MM) | 81.3% | Coming soon | Coming soon |

### Knowledge

- Winner: Directional only
- Gemini 3.1 Pro public-lane score: 67.6 (Supported · #26/184)
- GPT-5.3 Codex public-lane score: 65.4 (Estimated · #33/184)

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 94.3% | Coming soon | Coming soon |
| HLE w/o tools | 45.4% | Coming soon | Coming soon |
| HealthBench Hard | 20.6% | Coming soon | Coming soon |
| MedXpertQA (Text) | 71.5% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 95.5% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 91.0% | Coming soon | Coming soon |

### Instruction Following

- Winner: Not comparable
- Gemini 3.1 Pro public-lane score: Coming soon
- GPT-5.3 Codex public-lane score: 92.6 (#18/148)

### Mathematics

- Winner: Not comparable
- Gemini 3.1 Pro public-lane score: 65 (Unranked · 2 rankable rows)
- GPT-5.3 Codex public-lane score: Coming soon

| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 59.649% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 26.829% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Gemini 3.1 Pro or GPT-5.3 Codex?

Gemini 3.1 Pro has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Gemini 3.1 Pro and GPT-5.3 Codex?

The widest category gap is in reasoning, where the averages are 58.2 for Gemini 3.1 Pro and 83.1 for GPT-5.3 Codex.

### How many benchmarks does Gemini 3.1 Pro cover on BenchLM?

Gemini 3.1 Pro currently has 30 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.3 Codex cover on BenchLM?

GPT-5.3 Codex currently has 11 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Gemini 3.1 Pro vs GPT-5.3-Codex-Spark](/compare/gemini-3-1-pro-vs-gpt-5-3-codex-spark)
- [GPT-5.3 Codex vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-vs-gpt-5-3-codex-spark)
- [Gemini 3.1 Pro vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gemini-3-1-pro)
- [GPT-5.3 Codex vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-5-3-codex)

## Explore More

- [Gemini 3.1 Pro profile](/models/gemini-3-1-pro)
- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)