# GLM-5.3-Flash vs GPT-6 Astra

> GPT-6 Astra is the stronger model overall, scoring 70.8 to 51.8 on the Noometry Index. GLM-5.3-Flash costs 84× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/glm-5-3-flash-vs-gpt-6-astra
- Last updated: 2026-10-12
- Shared benchmarks: 38

## Summary

- They share 38 benchmarks with published results for both. GLM-5.3-Flash scores higher in 3 categories and GPT-6 Astra in 7 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-6 Astra leads 93.5 to 53.3.
- The biggest single-benchmark swing is FrontierMath Tier 4: 17.1% for GLM-5.3-Flash and 97.6% for GPT-6 Astra.
- GLM-5.3-Flash is cheaper at $0.15 / $0.50 per million input/output tokens, against $10 / $50 for GPT-6 Astra.
- GPT-6 Astra accepts more context: 1.05M tokens versus 1M.
- GLM-5.3-Flash has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 51.8 | 70.8 |
| Rank | 41 | 1 |
| Context | 1M | 1.05M |
| Input $/M | $0.15 | $10 |
| Output $/M | $0.50 | $50 |
| Weights | Open | Proprietary |

## Coding

- GLM-5.3-Flash: 53.1 (#31)
- GPT-6 Astra: 73.7 (#2)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| DeepSWE | 63.4% | 74.1% |
| FrontierCode | 31.8% | 53.3% |
| LMArena WebDev | 1609 | 1786 |
| FrontierSWE | 18.1% | 65.5% |
| SciCode | 51.6% | 56.5% |
| LMArena Coding | 1508 | 1487 |
| ALE-Bench | 303.55 | 2,951 |
| CursorBench | 36.8% | — |
| GSO | — | 79.4% |
| WeirdML | — | 93.6% |
| MirrorCode | — | 46.7% |

## Agentic & Tool Use

- GLM-5.3-Flash: 34.2 (#47)
- GPT-6 Astra: 52.9 (#3)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| APEX-Agents | 52.8% | 64.7% |
| GDP.pdf | 14% | 34.2% |
| Remote Labor Index | — | 20.8% |
| BALROG | — | 68.3% |
| Vending-Bench 2 | — | 15,515 |

## Reasoning

- GLM-5.3-Flash: 48.0 (#42)
- GPT-6 Astra: 85.1 (#1)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| ARC-AGI-2 | 65.8% | 95% |
| ARC-AGI-1 | 91% | 98.5% |
| CritPt | 15.4% | 31.7% |
| Chess Puzzles | 14% | 72% |
| LMArena Hard Prompts | 1491 | 1462 |
| Mystery Game Puzzles | 8% | 84% |
| Bench to the Future 3 | 0.15 | 0.14 |
| Epoch Capabilities Index | 151.88 | 166.45 |
| NYT Connections (extended) | — | 98.1% |
| EBR-Bench | — | 76.2% |
| DTBench | — | 97.3% |
| LMCA | — | 64.4% |
| Surface Evolver Bench | 52.5% | — |

## Math

- GLM-5.3-Flash: 53.3 (#47)
- GPT-6 Astra: 93.5 (#2)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| FrontierMath (Tiers 1-3) | 55.8% | 93.7% |
| FrontierMath Tier 4 | 17.1% | 97.6% |
| OTIS Mock AIME 2024-2025 | 93.9% | 100% |
| ProofBench | 21% | 99% |
| LMArena Math | 1500 | 1465 |
| FrontierMath Erdős | — | 2.9% |

## Knowledge

- GLM-5.3-Flash: 58.4 (#36)
- GPT-6 Astra: 75.3 (#1)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| GPQA Diamond | 90.2% | 95.8% |
| LMArena Expert | 1513 | 1483 |
| Humanity's Last Exam | — | 54.8% |
| SimpleQA Verified | — | 75.6% |
| Vectara Hallucination Rate | — | 8.7% |

## Multimodal

- GLM-5.3-Flash: 42.8 (#27)
- GPT-6 Astra: 55.0 (#3)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| LMArena Vision | 1296 | 1281 |
| Blueprint-Bench 2 | — | 49.7% |
| Furniture Assembly | — | 80% |
| LMArena Document | — | 1468 |

## Multilingual

- GLM-5.3-Flash: 56.0 (#25)
- GPT-6 Astra: 53.7 (#61)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| LMArena Non-English | 1462 | 1430 |
| LMArena Chinese | 1527 | 1484 |
| LMArena French | 1496 | 1456 |
| LMArena German | 1470 | 1440 |
| LMArena Japanese | 1429 | 1379 |
| LMArena Korean | 1446 | 1426 |
| LMArena Russian | 1469 | 1436 |
| LMArena Spanish | 1471 | 1407 |

## Instruction Following

- GLM-5.3-Flash: 77.5 (#20)
- GPT-6 Astra: 76.3 (#44)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| LMArena Instruction Following | 1478 | 1450 |

## Long Context

- GLM-5.3-Flash: 45.4 (#39)
- GPT-6 Astra: 44.5 (#62)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| LMArena Longer Query | 1482 | 1456 |

## Writing & Preference

- GLM-5.3-Flash: 65.3 (#50)
- GPT-6 Astra: 75.3 (#7)

| Benchmark | GLM-5.3-Flash | GPT-6 Astra |
|---|---|---|
| LMArena Text | 1471 | 1441 |
| LMArena Creative Writing | 1442 | 1418 |
| LMArena Multi-Turn | 1467 | 1448 |
| EQ-Bench Creative Writing | — | 2173 |

## FAQ

### Is GLM-5.3-Flash better than GPT-6 Astra?

GPT-6 Astra is the stronger model overall, scoring 70.8 to 51.8 on the Noometry Index. GLM-5.3-Flash costs 84× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

### Which is cheaper, GLM-5.3-Flash or GPT-6 Astra?

GLM-5.3-Flash is cheaper. It lists at $0.15 per million input tokens and $0.50 per million output tokens; GPT-6 Astra lists at $10 and $50.

### Is GLM-5.3-Flash or GPT-6 Astra better for coding?

GPT-6 Astra scores higher on coding benchmarks: 73.7 versus 53.1 in the Noometry coding category.

### Which has the bigger context window?

GPT-6 Astra does, with 1.05M tokens against 1M.

### How many benchmarks do GLM-5.3-Flash and GPT-6 Astra share?

38 benchmarks have published results for both models. GLM-5.3-Flash has 40 scored results on Noometry and GPT-6 Astra has 56.