# GLM-5.3 vs GPT-5.5 Pro

> GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 54.6 on the Noometry Index. GLM-5.3 costs 31× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/glm-5-3-vs-gpt-5-5-pro
- Last updated: 2026-10-10
- Shared benchmarks: 9

## Summary

- They share 9 benchmarks with published results for both. GLM-5.3 scores higher in 0 categories and GPT-5.5 Pro in 3 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.5 Pro leads 73.6 to 45.2.
- The biggest single-benchmark swing is FrontierMath Tier 4: 29.3% for GLM-5.3 and 78% for GPT-5.5 Pro.
- GLM-5.3 is cheaper at $1.40 / $4.40 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro 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 Pro |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 54.6 | 64.3 |
| Rank | 25 | 7 |
| Context | 1M | 1.05M |
| Input $/M | $1.40 | $30 |
| Output $/M | $4.40 | $180 |
| Weights | Open | Proprietary |

## Coding

- GLM-5.3: 59.0 (#12)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| DeepSWE | 69% | — |
| FrontierCode | 40.1% | — |
| LMArena WebDev | 1623 | — |
| FrontierSWE | 30.2% | — |
| SciCode | 59% | — |
| WeirdML | 75.4% | — |
| LMArena Coding | 1499 | — |
| ALE-Bench | 1,317 | — |

## Agentic & Tool Use

- GLM-5.3: 36.3 (#34)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| APEX-Agents | 56.6% | — |
| Vending-Bench 2 | 8,164 | — |

## Reasoning

- GLM-5.3: 45.2 (#42)
- GPT-5.5 Pro: 73.6 (#7)

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| CritPt | 19.1% | 30.6% |
| Chess Puzzles | 21% | 64% |
| DTBench | 87.7% | 96% |
| LMCA | 55.5% | 53.9% |
| Epoch Capabilities Index | 155.56 | 162.45 |
| ARC-AGI-2 | — | 84.6% |
| SimpleBench | — | 76.9% |
| NYT Connections (extended) | 74.2% | — |
| ARC-AGI-1 | — | 96.5% |
| LMArena Hard Prompts | 1491 | — |
| Mystery Game Puzzles | 33% | — |
| Bench to the Future 3 | 0.15 | — |

## Math

- GLM-5.3: 62.1 (#27)
- GPT-5.5 Pro: 83.8 (#8)

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 68.8% | 87.7% |
| FrontierMath Tier 4 | 29.3% | 78% |
| OTIS Mock AIME 2024-2025 | 91.1% | 100% |
| ProofBench | 49% | — |
| LMArena Math | 1493 | — |
| FrontierMath (Feb 2025 set) | — | 52.4% |
| FrontierMath Tier 4 (v1) | — | 39.6% |

## Knowledge

- GLM-5.3: 58.3 (#34)
- GPT-5.5 Pro: 64.2 (#17)

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| GPQA Diamond | 90.9% | 93.9% |
| SimpleQA Verified | 41% | — |
| LMArena Expert | 1512 | — |

## Multilingual

- GLM-5.3: 55.9 (#27)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| LMArena Non-English | 1457 | — |
| LMArena Chinese | 1523 | — |
| LMArena French | 1499 | — |
| LMArena German | 1505 | — |
| LMArena Japanese | 1438 | — |
| LMArena Korean | 1478 | — |
| LMArena Russian | 1460 | — |
| LMArena Spanish | 1444 | — |

## Instruction Following

- GLM-5.3: 77.8 (#15)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| LMArena Instruction Following | 1481 | — |

## Long Context

- GLM-5.3: 45.5 (#32)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| LMArena Longer Query | 1485 | — |

## Writing & Preference

- GLM-5.3: 75.9 (#6)
- GPT-5.5 Pro: —

| Benchmark | GLM-5.3 | GPT-5.5 Pro |
|---|---|---|
| LMArena Text | 1473 | — |
| LMArena Creative Writing | 1459 | — |
| EQ-Bench Creative Writing | 2075 | — |
| LMArena Multi-Turn | 1473 | — |

## FAQ

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

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 54.6 on the Noometry Index. GLM-5.3 costs 31× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

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

GLM-5.3 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; GPT-5.5 Pro lists at $30 and $180.

### Which has the bigger context window?

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

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

9 benchmarks have published results for both models. GLM-5.3 has 41 scored results on Noometry and GPT-5.5 Pro has 14.