# GLM-4.6 vs GPT-5.5 Pro

> GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 41.4 on the Noometry Index. GLM-4.6 costs 68× 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-4-6-vs-gpt-5-5-pro
- Last updated: 2026-10-12
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. GLM-4.6 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 73.3 to 23.7.
- The biggest single-benchmark swing is CritPt: 1.1% for GLM-4.6 and 30.6% for GPT-5.5 Pro.
- GLM-4.6 is cheaper at $0.60 / $2.20 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro accepts more context: 1.05M tokens versus 205K.
- GLM-4.6 has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 41.4 | 64.3 |
| Rank | 135 | 8 |
| Context | 205K | 1.05M |
| Input $/M | $0.60 | $30 |
| Output $/M | $2.20 | $180 |
| Weights | Open | Proprietary |

## Coding

- GLM-4.6: 40.1 (#148)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| SWE-bench Verified (bash only) | 55.4% | — |
| LMArena WebDev | 1340 | — |
| SciCode | 38.4% | — |
| LMArena Coding | 1449 | — |
| ALE-Bench | 340.82 | — |

## Agentic & Tool Use

- GLM-4.6: 32.3 (#66)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| Terminal-Bench | 24.5% | — |
| Berkeley Function Calling Leaderboard | 72.4% | — |

## Reasoning

- GLM-4.6: 23.7 (#172)
- GPT-5.5 Pro: 73.3 (#10)

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| CritPt | 1.1% | 30.6% |
| ARC-AGI-2 | — | 84.6% |
| SimpleBench | — | 76.9% |
| Kagi LLM Benchmark | 47.4% | — |
| ARC-AGI-1 | — | 96.5% |
| Chess Puzzles | — | 64% |
| LMArena Hard Prompts | 1440 | — |
| DTBench | — | 96% |
| LMCA | — | 53.9% |
| Epoch Capabilities Index | — | 162.07 |

## Math

- GLM-4.6: 39.1 (#111)
- GPT-5.5 Pro: 84.0 (#10)

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| FrontierMath (Feb 2025 set) | 3.8% | 52.4% |
| FrontierMath Tier 4 (v1) | 2.1% | 39.6% |
| FrontierMath (Tiers 1-3) | — | 87.7% |
| FrontierMath Tier 4 | — | 78% |
| OTIS Mock AIME 2024-2025 | — | 100% |
| LMArena Math | 1432 | — |

## Knowledge

- GLM-4.6: 40.2 (#124)
- GPT-5.5 Pro: 64.1 (#19)

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| GPQA Diamond | — | 93.9% |
| Vectara Hallucination Rate | 9.5% | — |
| LMArena Expert | 1431 | — |

## Multilingual

- GLM-4.6: 53.5 (#66)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| LMArena Non-English | 1426 | — |
| LMArena Chinese | 1499 | — |
| LMArena French | 1459 | — |
| LMArena German | 1447 | — |
| LMArena Japanese | 1393 | — |
| LMArena Korean | 1400 | — |
| LMArena Russian | 1419 | — |
| LMArena Spanish | 1436 | — |

## Instruction Following

- GLM-4.6: 74.3 (#98)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| LMArena Instruction Following | 1410 | — |

## Long Context

- GLM-4.6: 43.4 (#94)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| LMArena Longer Query | 1422 | — |

## Writing & Preference

- GLM-4.6: 61.1 (#90)
- GPT-5.5 Pro: —

| Benchmark | GLM-4.6 | GPT-5.5 Pro |
|---|---|---|
| LMArena Text | 1440 | — |
| LMArena Creative Writing | 1411 | — |
| EQ-Bench Creative Writing | 1411 | — |
| LMArena Multi-Turn | 1427 | — |

## FAQ

### Is GLM-4.6 better than GPT-5.5 Pro?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 41.4 on the Noometry Index. GLM-4.6 costs 68× 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-4.6 or GPT-5.5 Pro?

GLM-4.6 is cheaper. It lists at $0.60 per million input tokens and $2.20 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 205K.

### How many benchmarks do GLM-4.6 and GPT-5.5 Pro share?

3 benchmarks have published results for both models. GLM-4.6 has 29 scored results on Noometry and GPT-5.5 Pro has 14.