# Gemini 3.8 Flash vs GLM-4.5-Air

> Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 38.7 on the Noometry Index. GLM-4.5-Air costs 3.5× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-3-8-flash-vs-glm-4-5-air
- 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 GLM-4.5-Air 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 23.3.
- The biggest single-benchmark swing is Humanity's Last Exam: 44.5% for Gemini 3.8 Flash and 8.1% for GLM-4.5-Air.
- GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $0.75 / $3.75 for Gemini 3.8 Flash.
- Gemini 3.8 Flash accepts more context: 1.05M tokens versus 131K.
- GLM-4.5-Air has downloadable open weights; the other is API-only.

## Snapshot

| | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| Provider | Google | Z.ai (Zhipu) |
| Noometry Index | 59.5 | 38.7 |
| Rank | 13 | 169 |
| Context | 1.05M | 131K |
| Input $/M | $0.75 | $0.20 |
| Output $/M | $3.75 | $1.10 |
| Weights | Proprietary | Open |

## Coding

- Gemini 3.8 Flash: 56.4 (#17)
- GLM-4.5-Air: 34.5 (#225)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Coding | 1512 | 1397 |
| DeepSWE | 73.8% | — |
| FrontierCode | 41.2% | — |
| CursorBench | 39.6% | — |
| LMArena WebDev | 1581 | — |
| FrontierSWE | 19.6% | — |
| SciCode | 56.6% | — |
| GSO | — | 2.9% |
| ALE-Bench | 1,270 | — |

## Agentic & Tool Use

- Gemini 3.8 Flash: 40.3 (#22)
- GLM-4.5-Air: —

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| APEX-Agents | 64.3% | — |
| GDP.pdf | 23.4% | — |
| Vending-Bench 2 | 5,094 | — |

## Reasoning

- Gemini 3.8 Flash: 64.7 (#13)
- GLM-4.5-Air: 23.3 (#166)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Hard Prompts | 1506 | 1379 |
| Kagi LLM Benchmark | — | 43% |
| 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 | — |
| ForecastBench | — | 59.2 |

## Math

- Gemini 3.8 Flash: 65.2 (#22)
- GLM-4.5-Air: 33.8 (#166)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Math | 1528 | 1396 |
| FrontierMath (Tiers 1-3) | 68.4% | — |
| FrontierMath Tier 4 | 22% | — |
| OTIS Mock AIME 2024-2025 | 98.9% | — |
| ProofBench | 48% | — |
| Omni-MATH | — | 39.1% |

## Knowledge

- Gemini 3.8 Flash: 74.9 (#2)
- GLM-4.5-Air: 34.6 (#184)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| Humanity's Last Exam | 44.5% | 8.1% |
| LMArena Expert | 1529 | 1370 |
| GPQA Diamond | 95.4% | — |
| SimpleQA Verified | 69.7% | — |
| MMLU-Pro | — | 76.2% |
| Vectara Hallucination Rate | — | 9.3% |
| GPQA (HELM) | — | 59.4% |

## Multimodal

- Gemini 3.8 Flash: 40.9 (#33)
- GLM-4.5-Air: —

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Vision | 1312 | — |
| Blueprint-Bench 2 | 38.6% | — |
| Furniture Assembly | 31.7% | — |

## Multilingual

- Gemini 3.8 Flash: 57.9 (#5)
- GLM-4.5-Air: 49.4 (#130)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Non-English | 1486 | 1366 |
| LMArena Chinese | 1547 | 1427 |
| LMArena French | 1502 | 1399 |
| LMArena German | 1470 | 1376 |
| LMArena Japanese | 1505 | 1348 |
| LMArena Korean | 1479 | 1306 |
| LMArena Russian | 1507 | 1373 |
| LMArena Spanish | 1492 | 1385 |

## Instruction Following

- Gemini 3.8 Flash: 78.2 (#11)
- GLM-4.5-Air: 69.8 (#165)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Instruction Following | 1489 | 1353 |
| IFEval | — | 81.2% |

## Long Context

- Gemini 3.8 Flash: 46.2 (#23)
- GLM-4.5-Air: 41.6 (#130)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Longer Query | 1506 | 1367 |

## Writing & Preference

- Gemini 3.8 Flash: 72.1 (#16)
- GLM-4.5-Air: 56.1 (#134)

| Benchmark | Gemini 3.8 Flash | GLM-4.5-Air |
|---|---|---|
| LMArena Text | 1494 | 1384 |
| LMArena Creative Writing | 1485 | 1343 |
| LMArena Multi-Turn | 1503 | 1371 |
| EQ-Bench Creative Writing | 1748 | — |
| WildBench | — | 78.9% |

## FAQ

### Is Gemini 3.8 Flash better than GLM-4.5-Air?

Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 38.7 on the Noometry Index. GLM-4.5-Air costs 3.5× less per token, which makes it the better buy when Gemini 3.8 Flash's lead doesn't matter for your workload.

### Which is cheaper, Gemini 3.8 Flash or GLM-4.5-Air?

GLM-4.5-Air is cheaper. It lists at $0.20 per million input tokens and $1.10 per million output tokens; Gemini 3.8 Flash lists at $0.75 and $3.75.

### Is Gemini 3.8 Flash or GLM-4.5-Air better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 56.4 versus 34.5 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 131K.

### How many benchmarks do Gemini 3.8 Flash and GLM-4.5-Air share?

18 benchmarks have published results for both models. Gemini 3.8 Flash has 46 scored results on Noometry and GLM-4.5-Air has 27.