# Gemini 2.5 Flash-Lite vs GPT-5-Codex

> Gemini 2.5 Flash-Lite and GPT-5-Codex score almost the same on the Noometry Index (37.0 vs 37.9), so choose on price, context window or the category you care about most.

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

## Summary

- They share 2 benchmarks with published results for both. Gemini 2.5 Flash-Lite scores higher in 0 categories and GPT-5-Codex in 3 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5-Codex leads 30.9 to 22.2.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 40.5% for Gemini 2.5 Flash-Lite and 70.3% for GPT-5-Codex.
- Gemini 2.5 Flash-Lite is cheaper at $0.10 / $0.40 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- Gemini 2.5 Flash-Lite accepts more context: 1.05M tokens versus 400K.

## Snapshot

| | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 37.0 | 37.9 |
| Rank | 211 | 192 |
| Context | 1.05M | 400K |
| Input $/M | $0.10 | $1.25 |
| Output $/M | $0.40 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 2.5 Flash-Lite: 38.5 (#173)
- GPT-5-Codex: 42.4 (#103)

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| WeirdML | 35.2% | 54.5% |
| LMArena Coding | 1373 | — |
| ALE-Bench | 325.9 | — |

## Agentic & Tool Use

- Gemini 2.5 Flash-Lite: 28.0 (#96)
- GPT-5-Codex: 31.0 (#72)

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| Terminal-Bench | — | 44.3% |
| Berkeley Function Calling Leaderboard | 36.9% | — |

## Reasoning

- Gemini 2.5 Flash-Lite: 22.2 (#205)
- GPT-5-Codex: 30.9 (#83)

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| Kagi LLM Benchmark | 40.5% | 70.3% |
| LMArena Hard Prompts | 1377 | — |
| DTBench | 62.8% | — |
| LMCA | 18.1% | — |
| Epoch Capabilities Index | 133.94 | — |

## Math

- Gemini 2.5 Flash-Lite: 38.0 (#144)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| Omni-MATH | 48% | — |
| LMArena Math | 1373 | — |

## Knowledge

- Gemini 2.5 Flash-Lite: 32.5 (#210)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| MMLU-Pro | 53.7% | — |
| Vectara Hallucination Rate | 3.3% | — |
| GPQA (HELM) | 30.9% | — |
| LMArena Expert | 1373 | — |

## Multimodal

- Gemini 2.5 Flash-Lite: 29.1 (#114)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| LMArena Vision | 1198 | — |
| VPCT | 30% | — |

## Multilingual

- Gemini 2.5 Flash-Lite: 49.3 (#134)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| LMArena Non-English | 1369 | — |
| LMArena Chinese | 1404 | — |
| LMArena French | 1388 | — |
| LMArena German | 1389 | — |
| LMArena Japanese | 1359 | — |
| LMArena Korean | 1360 | — |
| LMArena Russian | 1373 | — |
| LMArena Spanish | 1396 | — |

## Instruction Following

- Gemini 2.5 Flash-Lite: 70.0 (#168)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| IFEval | 81% | — |
| LMArena Instruction Following | 1367 | — |

## Long Context

- Gemini 2.5 Flash-Lite: 33.3 (#262)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| Fiction.LiveBench | 47.2% | — |
| LMArena Longer Query | 1373 | — |

## Writing & Preference

- Gemini 2.5 Flash-Lite: 56.8 (#135)
- GPT-5-Codex: —

| Benchmark | Gemini 2.5 Flash-Lite | GPT-5-Codex |
|---|---|---|
| LMArena Text | 1379 | — |
| LMArena Creative Writing | 1367 | — |
| WildBench | 81.8% | — |
| LMArena Multi-Turn | 1366 | — |

## FAQ

### Is Gemini 2.5 Flash-Lite better than GPT-5-Codex?

Gemini 2.5 Flash-Lite and GPT-5-Codex score almost the same on the Noometry Index (37.0 vs 37.9), so choose on price, context window or the category you care about most.

### Which is cheaper, Gemini 2.5 Flash-Lite or GPT-5-Codex?

Gemini 2.5 Flash-Lite is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is Gemini 2.5 Flash-Lite or GPT-5-Codex better for coding?

GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 38.5 in the Noometry coding category.

### Which has the bigger context window?

Gemini 2.5 Flash-Lite does, with 1.05M tokens against 400K.

### How many benchmarks do Gemini 2.5 Flash-Lite and GPT-5-Codex share?

2 benchmarks have published results for both models. Gemini 2.5 Flash-Lite has 33 scored results on Noometry and GPT-5-Codex has 3.