# GLM-5.3 vs GPT-5.5

> GPT-5.5 is the stronger model overall, scoring 63.4 to 54.6 on the Noometry Index. GLM-5.3 costs 5.2× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/glm-5-3-vs-gpt-5-5
- Last updated: 2026-10-10
- Shared benchmarks: 40

## Summary

- They share 40 benchmarks with published results for both. GLM-5.3 scores higher in 3 categories and GPT-5.5 in 6 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 leads 72.7 to 45.2.
- The biggest single-benchmark swing is FrontierMath Tier 4: 29.3% for GLM-5.3 and 72.5% for GPT-5.5.
- GLM-5.3 is cheaper at $1.40 / $4.40 per million input/output tokens, against $5 / $30 for GPT-5.5.
- GPT-5.5 accepts more context: 1.05M tokens versus 1M.
- GLM-5.3 has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-5.3 | GPT-5.5 |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 54.6 | 63.4 |
| Rank | 25 | 8 |
| Context | 1M | 1.05M |
| Input $/M | $1.40 | $5 |
| Output $/M | $4.40 | $30 |
| Weights | Open | Proprietary |

## Coding

- GLM-5.3: 59.0 (#12)
- GPT-5.5: 58.3 (#13)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| DeepSWE | 69% | 67% |
| FrontierCode | 40.1% | 43% |
| LMArena WebDev | 1623 | 1512 |
| SciCode | 59% | 56.1% |
| WeirdML | 75.4% | 84.9% |
| LMArena Coding | 1499 | 1494 |
| ALE-Bench | 1,317 | 1,943 |
| SWE-bench Verified | — | 80.6% |
| FrontierSWE | 30.2% | — |
| GSO | — | 40.2% |
| MirrorCode | — | 10% |

## Agentic & Tool Use

- GLM-5.3: 36.3 (#34)
- GPT-5.5: 50.7 (#6)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| APEX-Agents | 56.6% | 55.1% |
| Vending-Bench 2 | 8,164 | 7,524 |
| Terminal-Bench | — | 84.7% |
| OSWorld 2.0 | — | 13% |
| Remote Labor Index | — | 6.3% |
| τ²-bench Banking | — | 44.6% |
| DeepResearch Bench | — | 54% |
| PostTrainBench | — | 27.2% |
| ExploitBench | — | 47.4% |
| GBAEval | — | 53.2% |
| GDP.pdf | — | 26% |
| LMArena Search | — | 1242 |

## Reasoning

- GLM-5.3: 45.2 (#42)
- GPT-5.5: 72.7 (#8)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| NYT Connections (extended) | 74.2% | 96.2% |
| CritPt | 19.1% | 27.1% |
| Chess Puzzles | 21% | 54% |
| LMArena Hard Prompts | 1491 | 1489 |
| Mystery Game Puzzles | 33% | 56% |
| DTBench | 87.7% | 96% |
| LMCA | 55.5% | 54.3% |
| Bench to the Future 3 | 0.15 | 0.14 |
| Epoch Capabilities Index | 155.56 | 159.25 |
| ARC-AGI-2 | — | 85% |
| SimpleBench | — | 69% |
| Kagi LLM Benchmark | — | 88.8% |
| ARC-AGI-1 | — | 95% |
| EBR-Bench | — | 34.3% |
| Surface Evolver Bench | — | 88.1% |
| ForecastBench | — | 60.6 |

## Math

- GLM-5.3: 62.1 (#27)
- GPT-5.5: 81.5 (#9)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 68.8% | 85.3% |
| FrontierMath Tier 4 | 29.3% | 72.5% |
| OTIS Mock AIME 2024-2025 | 91.1% | 100% |
| ProofBench | 49% | 50% |
| LMArena Math | 1493 | 1486 |
| MathArena Final-Answer Competitions | — | 94.3% |
| FrontierMath (Feb 2025 set) | — | 51.7% |
| FrontierMath Erdős | — | 0% |
| FrontierMath Tier 4 (v1) | — | 35.4% |

## Knowledge

- GLM-5.3: 58.3 (#34)
- GPT-5.5: 64.4 (#14)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| GPQA Diamond | 90.9% | 94% |
| SimpleQA Verified | 41% | 63% |
| LMArena Expert | 1512 | 1508 |
| Vectara Hallucination Rate | — | 9.3% |

## Multimodal

- GLM-5.3: —
- GPT-5.5: 47.1 (#11)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| LMArena Vision | — | 1297 |
| Blueprint-Bench 2 | — | 36.2% |
| Furniture Assembly | — | 44.2% |
| LMArena Document | — | 1486 |

## Multilingual

- GLM-5.3: 55.9 (#27)
- GPT-5.5: 56.5 (#19)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| LMArena Non-English | 1457 | 1467 |
| LMArena Chinese | 1523 | 1535 |
| LMArena French | 1499 | 1486 |
| LMArena German | 1505 | 1478 |
| LMArena Japanese | 1438 | 1498 |
| LMArena Korean | 1478 | 1461 |
| LMArena Russian | 1460 | 1473 |
| LMArena Spanish | 1444 | 1469 |

## Instruction Following

- GLM-5.3: 77.8 (#15)
- GPT-5.5: 77.7 (#18)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| LMArena Instruction Following | 1481 | 1479 |

## Long Context

- GLM-5.3: 45.5 (#32)
- GPT-5.5: 48.3 (#12)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| LMArena Longer Query | 1485 | 1484 |
| CL-bench Life | — | 22.2% |

## Writing & Preference

- GLM-5.3: 75.9 (#6)
- GPT-5.5: 72.8 (#13)

| Benchmark | GLM-5.3 | GPT-5.5 |
|---|---|---|
| LMArena Text | 1473 | 1471 |
| LMArena Creative Writing | 1459 | 1455 |
| EQ-Bench Creative Writing | 2075 | 1844 |
| LMArena Multi-Turn | 1473 | 1477 |
| EQ-Bench 4 | — | 1315 |

## FAQ

### Is GLM-5.3 better than GPT-5.5?

GPT-5.5 is the stronger model overall, scoring 63.4 to 54.6 on the Noometry Index. GLM-5.3 costs 5.2× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

### Which is cheaper, GLM-5.3 or GPT-5.5?

GLM-5.3 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; GPT-5.5 lists at $5 and $30.

### Is GLM-5.3 or GPT-5.5 better for coding?

They score almost the same on coding (59.0 vs 58.3); test both on your own repository before choosing.

### Which has the bigger context window?

GPT-5.5 does, with 1.05M tokens against 1M.

### How many benchmarks do GLM-5.3 and GPT-5.5 share?

40 benchmarks have published results for both models. GLM-5.3 has 41 scored results on Noometry and GPT-5.5 has 71.