# GLM-5.3-Flash vs o3

> GLM-5.3-Flash is the stronger model overall, scoring 51.8 to 47.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/glm-5-3-flash-vs-o3
- Last updated: 2026-10-11
- Shared benchmarks: 28

## Summary

- They share 28 benchmarks with published results for both. GLM-5.3-Flash scores higher in 8 categories and o3 in 2 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GLM-5.3-Flash leads 48.0 to 32.0.
- The biggest single-benchmark swing is ARC-AGI-2: 65.8% for GLM-5.3-Flash and 6.5% for o3.
- GLM-5.3-Flash is cheaper at $0.15 / $0.50 per million input/output tokens, against $2 / $8 for o3.
- GLM-5.3-Flash accepts more context: 1M tokens versus 200K.
- GLM-5.3-Flash has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-5.3-Flash | o3 |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 51.8 | 47.5 |
| Rank | 41 | 61 |
| Context | 1M | 200K |
| Input $/M | $0.15 | $2 |
| Output $/M | $0.50 | $8 |
| Weights | Open | Proprietary |

## Coding

- GLM-5.3-Flash: 53.1 (#31)
- o3: 46.8 (#64)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Coding | 1508 | 1408 |
| ALE-Bench | 303.55 | 933.55 |
| SWE-bench Verified | — | 62.3% |
| DeepSWE | 63.4% | — |
| FrontierCode | 31.8% | — |
| SWE-bench Verified (bash only) | — | 58.4% |
| Aider Polyglot | — | 81.3% |
| CursorBench | 36.8% | — |
| LMArena WebDev | 1609 | — |
| FrontierSWE | 18.1% | — |
| SciCode | 51.6% | — |
| GSO | — | 8.8% |
| WeirdML | — | 52.4% |
| CadEval | — | 74% |

## Agentic & Tool Use

- GLM-5.3-Flash: 34.2 (#47)
- o3: 34.5 (#44)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| APEX-Agents | 52.8% | — |
| Berkeley Function Calling Leaderboard | — | 63% |
| GDPval | — | 30.8% |
| DeepResearch Bench | — | 45.2% |
| OSWorld | — | 23% |
| GDP.pdf | 14% | — |
| LMArena Search | — | 1144 |
| METR Time Horizons | — | 65.4% |

## Reasoning

- GLM-5.3-Flash: 48.0 (#42)
- o3: 32.0 (#78)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| ARC-AGI-2 | 65.8% | 6.5% |
| ARC-AGI-1 | 91% | 60.8% |
| CritPt | 15.4% | 1.4% |
| Chess Puzzles | 14% | 38% |
| LMArena Hard Prompts | 1491 | 1402 |
| Mystery Game Puzzles | 8% | 29% |
| Epoch Capabilities Index | 151.88 | 146.86 |
| SimpleBench | — | 53.1% |
| Kagi LLM Benchmark | — | 67.6% |
| EnigmaEval | — | 13.1% |
| DTBench | — | 84.8% |
| LMCA | — | 39.7% |
| Surface Evolver Bench | 52.5% | — |
| Bench to the Future 3 | 0.15 | — |
| ForecastBench | — | 62.5 |

## Math

- GLM-5.3-Flash: 53.3 (#47)
- o3: 50.2 (#58)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 55.8% | 33.3% |
| OTIS Mock AIME 2024-2025 | 93.9% | 84.4% |
| LMArena Math | 1500 | 1426 |
| FrontierMath Tier 4 | 17.1% | — |
| ProofBench | 21% | — |
| Omni-MATH | — | 71.4% |
| MATH Level 5 | — | 97.8% |
| FrontierMath (Feb 2025 set) | — | 18.7% |
| FrontierMath Tier 4 (v1) | — | 2.1% |

## Knowledge

- GLM-5.3-Flash: 58.4 (#36)
- o3: 54.6 (#52)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| GPQA Diamond | 90.2% | 81.8% |
| LMArena Expert | 1513 | 1402 |
| Humanity's Last Exam | — | 20.3% |
| SimpleQA Verified | — | 49.4% |
| MMLU-Pro | — | 85.9% |
| Confabulations | — | 14.4% |
| GPQA (HELM) | — | 75.3% |

## Multimodal

- GLM-5.3-Flash: 42.8 (#27)
- o3: 41.4 (#36)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Vision | 1296 | 1214 |
| GeoBench | — | 74% |
| VPCT | — | 52% |

## Multilingual

- GLM-5.3-Flash: 56.0 (#25)
- o3: 51.7 (#105)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Non-English | 1462 | 1401 |
| LMArena Chinese | 1527 | 1437 |
| LMArena French | 1496 | 1430 |
| LMArena German | 1470 | 1420 |
| LMArena Japanese | 1429 | 1403 |
| LMArena Korean | 1446 | 1370 |
| LMArena Russian | 1469 | 1406 |
| LMArena Spanish | 1471 | 1395 |

## Instruction Following

- GLM-5.3-Flash: 77.5 (#20)
- o3: 72.8 (#127)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Instruction Following | 1478 | 1368 |
| IFEval | — | 86.9% |

## Long Context

- GLM-5.3-Flash: 45.4 (#39)
- o3: 53.3 (#6)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Longer Query | 1482 | 1372 |
| Fiction.LiveBench | — | 88.9% |
| CL-bench | — | 17.8% |

## Writing & Preference

- GLM-5.3-Flash: 65.3 (#50)
- o3: 63.5 (#64)

| Benchmark | GLM-5.3-Flash | o3 |
|---|---|---|
| LMArena Text | 1471 | 1410 |
| LMArena Creative Writing | 1442 | 1359 |
| LMArena Multi-Turn | 1467 | 1405 |
| Short-Story Creative Writing | — | 83.9% |
| EQ-Bench Creative Writing | — | 1676 |
| WildBench | — | 86.1% |

## FAQ

### Is GLM-5.3-Flash better than o3?

GLM-5.3-Flash is the stronger model overall, scoring 51.8 to 47.5 on the Noometry Index.

### Which is cheaper, GLM-5.3-Flash or o3?

GLM-5.3-Flash is cheaper. It lists at $0.15 per million input tokens and $0.50 per million output tokens; o3 lists at $2 and $8.

### Is GLM-5.3-Flash or o3 better for coding?

GLM-5.3-Flash scores higher on coding benchmarks: 53.1 versus 46.8 in the Noometry coding category.

### Which has the bigger context window?

GLM-5.3-Flash does, with 1M tokens against 200K.

### How many benchmarks do GLM-5.3-Flash and o3 share?

28 benchmarks have published results for both models. GLM-5.3-Flash has 40 scored results on Noometry and o3 has 63.