# Gemini 3 Flash vs GPT-5.2-Codex

> Side-by-side benchmark comparison for Gemini 3 Flash and GPT-5.2-Codex across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-flash-vs-gpt-5-2-codex
- Last updated: October 19, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

GPT-5.2-Codex leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- GPT-5.2-Codex has the higher overall point estimate 55.29 to 54.28. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in instruction following, where the averages are 66.1 for Gemini 3 Flash and 93.8 for GPT-5.2-Codex.
- The biggest single benchmark swing is Vibe Code Bench in Coding, with scores of 20.20% and 37.91%.
- Gemini 3 Flash is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Gemini 3 Flash also has the larger context window at 1M.

## Model Snapshot

| Property | Gemini 3 Flash | GPT-5.2-Codex |
|----------|----------|----------|
| Creator | Google | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 1M | 400K |
| Overall Score | 54.28 | 55.29 |
| Benchmarks Covered | 11 | 5 |
| Pricing (input/output) | $0.50 / $3.00 | $1.75 / $14.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Gemini 3 Flash public-lane score: 32.5 (Supported · #90/129)
- GPT-5.2-Codex public-lane score: 41.1 (Estimated · #65/129)

| Benchmark | Gemini 3 Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| Claw-Eval | 49.2% | Coming soon | Coming soon |
| Gert Labs | 56.63% | 51.79% | Gemini 3 Flash |
| JobBench | 11.4% | 26.0% | GPT-5.2-Codex |
| Terminal-Bench 2.1 (Vals) | 53.9% | Coming soon | Coming soon |

### Coding

- Winner: GPT-5.2-Codex
- Gemini 3 Flash public-lane score: 32.1 (Supported · #88/150)
- GPT-5.2-Codex public-lane score: 43.6 (Supported · #56/150)

| Benchmark | Gemini 3 Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 20.20% | 37.91% | GPT-5.2-Codex |
| LiveCodeBench (Vals) | 85.6% | 88.0% | GPT-5.2-Codex |
| SWE-bench (Vals) | 75.0% | 72.4% | Gemini 3 Flash |

### Reasoning

- Winner: Not comparable
- Gemini 3 Flash public-lane score: 63.8 (Unranked · 2 rankable rows)
- GPT-5.2-Codex public-lane score: 82.4 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Not comparable
- Gemini 3 Flash public-lane score: 80.3 (Unranked · 1 rankable row)
- GPT-5.2-Codex public-lane score: 76.9 (Unranked · 1 rankable row)

### Knowledge

- Winner: Directional only
- Gemini 3 Flash public-lane score: 55.7 (Supported · #55/185)
- GPT-5.2-Codex public-lane score: 56.4 (Estimated · #54/185)

| Benchmark | Gemini 3 Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 87.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 88.6% | Coming soon | Coming soon |

### Instruction Following

- Winner: Directional only
- Gemini 3 Flash public-lane score: 66.1 (#76/148)
- GPT-5.2-Codex public-lane score: 93.8 (#4/148)

### Mathematics

- Winner: Not comparable
- Gemini 3 Flash public-lane score: 57.4 (Unranked · 2 rankable rows)
- GPT-5.2-Codex public-lane score: Coming soon

| Benchmark | Gemini 3 Flash | GPT-5.2-Codex | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 51.228% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 17.073% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Gemini 3 Flash or GPT-5.2-Codex?

GPT-5.2-Codex has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Gemini 3 Flash and GPT-5.2-Codex?

The widest category gap is in instruction following, where the averages are 66.1 for Gemini 3 Flash and 93.8 for GPT-5.2-Codex.

### How many benchmarks does Gemini 3 Flash cover on BenchLM?

Gemini 3 Flash currently has 11 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.2-Codex cover on BenchLM?

GPT-5.2-Codex currently has 5 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Gemini 3 Flash vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gemini-3-flash)
- [GPT-5.2-Codex vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-5-2-codex)
- [Gemini 3 Flash vs GPT-6.1 Sol](/compare/gemini-3-flash-vs-gpt-6-1-sol)
- [GPT-5.2-Codex vs GPT-6.1 Sol](/compare/gpt-5-2-codex-vs-gpt-6-1-sol)

## Explore More

- [Gemini 3 Flash profile](/models/gemini-3-flash)
- [GPT-5.2-Codex profile](/models/gpt-5-2-codex)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)