# Gemini 3.8 Flash vs GPT-5.3 Chat

> Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 42.1 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gemini-3-8-flash-vs-gpt-5-3-chat
- Last updated: 2026-10-10
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 8 categories and GPT-5.3 Chat in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.8 Flash leads 64.7 to 27.3.
- Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- Gemini 3.8 Flash accepts more context: 1.05M tokens versus 128K.

## Snapshot

| | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 59.5 | 42.1 |
| Rank | 13 | 109 |
| Context | 1.05M | 128K |
| Input $/M | $0.75 | $1.75 |
| Output $/M | $3.75 | $14 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.8 Flash: 56.4 (#17)
- GPT-5.3 Chat: 40.8 (#124)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Coding | 1512 | 1408 |
| DeepSWE | 73.8% | — |
| FrontierCode | 41.2% | — |
| CursorBench | 39.6% | — |
| LMArena WebDev | 1581 | — |
| FrontierSWE | 19.6% | — |
| SciCode | 56.6% | — |
| ALE-Bench | 1,270 | — |

## Agentic & Tool Use

- Gemini 3.8 Flash: 40.3 (#22)
- GPT-5.3 Chat: —

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| APEX-Agents | 64.3% | — |
| GDP.pdf | 23.4% | — |
| Vending-Bench 2 | 5,094 | — |

## Reasoning

- Gemini 3.8 Flash: 64.7 (#13)
- GPT-5.3 Chat: 27.3 (#105)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Hard Prompts | 1506 | 1399 |
| NYT Connections (extended) | 97.4% | — |
| CritPt | 18.3% | — |
| Chess Puzzles | 61% | — |
| Mystery Game Puzzles | 47% | — |
| DTBench | 95.7% | — |
| LMCA | 52.9% | — |
| Surface Evolver Bench | 76.9% | — |
| Epoch Capabilities Index | 157.13 | — |

## Math

- Gemini 3.8 Flash: 65.2 (#22)
- GPT-5.3 Chat: 35.4 (#146)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Math | 1528 | 1389 |
| FrontierMath (Tiers 1-3) | 68.4% | — |
| FrontierMath Tier 4 | 22% | — |
| OTIS Mock AIME 2024-2025 | 98.9% | — |
| ProofBench | 48% | — |

## Knowledge

- Gemini 3.8 Flash: 74.9 (#2)
- GPT-5.3 Chat: 38.2 (#137)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Expert | 1529 | 1397 |
| GPQA Diamond | 95.4% | — |
| Humanity's Last Exam | 44.5% | — |
| SimpleQA Verified | 69.7% | — |

## Multimodal

- Gemini 3.8 Flash: 40.9 (#33)
- GPT-5.3 Chat: —

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Vision | 1312 | — |
| Blueprint-Bench 2 | 38.6% | — |
| Furniture Assembly | 31.7% | — |

## Multilingual

- Gemini 3.8 Flash: 57.9 (#5)
- GPT-5.3 Chat: 50.5 (#119)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Non-English | 1486 | 1383 |
| LMArena Chinese | 1547 | 1433 |
| LMArena French | 1502 | 1398 |
| LMArena German | 1470 | 1384 |
| LMArena Japanese | 1505 | 1351 |
| LMArena Korean | 1479 | 1347 |
| LMArena Russian | 1507 | 1400 |
| LMArena Spanish | 1492 | 1371 |

## Instruction Following

- Gemini 3.8 Flash: 78.2 (#11)
- GPT-5.3 Chat: 73.0 (#124)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Instruction Following | 1489 | 1378 |

## Long Context

- Gemini 3.8 Flash: 46.2 (#23)
- GPT-5.3 Chat: 42.6 (#115)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Longer Query | 1506 | 1396 |

## Writing & Preference

- Gemini 3.8 Flash: 72.1 (#16)
- GPT-5.3 Chat: 63.3 (#65)

| Benchmark | Gemini 3.8 Flash | GPT-5.3 Chat |
|---|---|---|
| LMArena Text | 1494 | 1389 |
| LMArena Creative Writing | 1485 | 1356 |
| EQ-Bench Creative Writing | 1748 | 1690 |
| LMArena Multi-Turn | 1503 | 1413 |

## FAQ

### Is Gemini 3.8 Flash better than GPT-5.3 Chat?

Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 42.1 on the Noometry Index.

### Which is cheaper, Gemini 3.8 Flash or GPT-5.3 Chat?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is Gemini 3.8 Flash or GPT-5.3 Chat better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 56.4 versus 40.8 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 128K.

### How many benchmarks do Gemini 3.8 Flash and GPT-5.3 Chat share?

18 benchmarks have published results for both models. Gemini 3.8 Flash has 46 scored results on Noometry and GPT-5.3 Chat has 18.