# GLM-5.1 vs GPT-5.3 Chat

> GLM-5.1 is the stronger model overall, scoring 47.6 to 42.1 on the Noometry Index.

- Canonical page: https://noometry.com/compare/glm-5-1-vs-gpt-5-3-chat
- Last updated: 2026-10-10
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. GLM-5.1 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 knowledge, where GLM-5.1 leads 55.0 to 38.2.
- GLM-5.1 is cheaper at $1.40 / $4.40 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- GLM-5.1 accepts more context: 200K tokens versus 128K.
- GLM-5.1 has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 47.6 | 42.1 |
| Rank | 51 | 109 |
| Context | 200K | 128K |
| Input $/M | $1.40 | $1.75 |
| Output $/M | $4.40 | $14 |
| Weights | Open | Proprietary |

## Coding

- GLM-5.1: 48.5 (#52)
- GPT-5.3 Chat: 40.8 (#124)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Coding | 1486 | 1408 |
| SWE-bench Verified | 74.2% | — |
| LMArena WebDev | 1509 | — |
| SciCode | 43.8% | — |
| WeirdML | 57.1% | — |
| ALE-Bench | 887.1 | — |

## Agentic & Tool Use

- GLM-5.1: 24.8 (#106)
- GPT-5.3 Chat: —

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| APEX-Agents | 40.9% | — |
| ExploitBench | 18.1% | — |
| GBAEval | 0% | — |
| Vending-Bench 2 | 5,634 | — |

## Reasoning

- GLM-5.1: 38.2 (#57)
- GPT-5.3 Chat: 27.3 (#105)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Hard Prompts | 1472 | 1399 |
| SimpleBench | 55.1% | — |
| NYT Connections (extended) | 77.7% | — |
| CritPt | 4.6% | — |
| Chess Puzzles | 19% | — |
| Thematic Generalization | 69.8% | — |
| Epoch Capabilities Index | 149.86 | — |

## Math

- GLM-5.1: 49.0 (#48)
- GPT-5.3 Chat: 35.4 (#146)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Math | 1472 | 1389 |
| FrontierMath (Tiers 1-3) | 36.8% | — |
| MathArena Final-Answer Competitions | 67.1% | — |
| OTIS Mock AIME 2024-2025 | 93.3% | — |
| ProofBench | 22.2% | — |
| FrontierMath (Feb 2025 set) | 33.4% | — |
| FrontierMath Tier 4 (v1) | 12.5% | — |

## Knowledge

- GLM-5.1: 55.0 (#45)
- GPT-5.3 Chat: 38.2 (#137)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Expert | 1477 | 1397 |
| GPQA Diamond | 89.9% | — |
| SimpleQA Verified | 34% | — |

## Multilingual

- GLM-5.1: 55.2 (#34)
- GPT-5.3 Chat: 50.5 (#119)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Non-English | 1448 | 1383 |
| LMArena Chinese | 1516 | 1433 |
| LMArena French | 1478 | 1398 |
| LMArena German | 1466 | 1384 |
| LMArena Japanese | 1436 | 1351 |
| LMArena Korean | 1423 | 1347 |
| LMArena Russian | 1453 | 1400 |
| LMArena Spanish | 1467 | 1371 |

## Instruction Following

- GLM-5.1: 76.5 (#41)
- GPT-5.3 Chat: 73.0 (#124)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Instruction Following | 1451 | 1378 |

## Long Context

- GLM-5.1: 44.9 (#51)
- GPT-5.3 Chat: 42.6 (#115)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Longer Query | 1467 | 1396 |

## Writing & Preference

- GLM-5.1: 67.2 (#29)
- GPT-5.3 Chat: 63.3 (#65)

| Benchmark | GLM-5.1 | GPT-5.3 Chat |
|---|---|---|
| LMArena Text | 1462 | 1389 |
| LMArena Creative Writing | 1454 | 1356 |
| EQ-Bench Creative Writing | 1592 | 1690 |
| LMArena Multi-Turn | 1473 | 1413 |

## FAQ

### Is GLM-5.1 better than GPT-5.3 Chat?

GLM-5.1 is the stronger model overall, scoring 47.6 to 42.1 on the Noometry Index.

### Which is cheaper, GLM-5.1 or GPT-5.3 Chat?

GLM-5.1 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is GLM-5.1 or GPT-5.3 Chat better for coding?

GLM-5.1 scores higher on coding benchmarks: 48.5 versus 40.8 in the Noometry coding category.

### Which has the bigger context window?

GLM-5.1 does, with 200K tokens against 128K.

### How many benchmarks do GLM-5.1 and GPT-5.3 Chat share?

18 benchmarks have published results for both models. GLM-5.1 has 41 scored results on Noometry and GPT-5.3 Chat has 18.