# GLM-5.1 vs GPT-5.5

> Side-by-side benchmark comparison for GLM-5.1 and GPT-5.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/glm-5-1-vs-gpt-5-5
- Last updated: September 4, 2026

- Shared sourced benchmarks: 17
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick GPT-5.5 if you want the stronger benchmark profile. GLM-5.1 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-5.5 leads overall 73.27 to 64.41.
- The clearest category separation is in knowledge, where the averages are 55.4 for GLM-5.1 and 73.3 for GPT-5.5.
- The biggest single benchmark swing is Vibe Code Bench in Coding, with scores of 31.46% and 69.85%.
- GLM-5.1 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- GPT-5.5 also has the larger context window at 1M.

## Model Snapshot

| Property | GLM-5.1 | GPT-5.5 |
|----------|----------|----------|
| Creator | Z.AI | OpenAI |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 203K | 1M |
| Overall Score | 64.41 | 73.27 |
| Benchmarks Covered | 26 | 38 |
| Pricing (input/output) | $1.40 / $4.40 | $5.00 / $30.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- GLM-5.1 public-lane score: 50.1 (Estimated · #63/151)
- GPT-5.5 public-lane score: 63.9 (Supported · #15/151)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 63.5% | 82% | GPT-5.5 |
| BrowseComp | 68% | 84.4% | GPT-5.5 |
| τ³-bench results | 70.6% | Coming soon | Coming soon |
| MCP Atlas | 71.8% | 75.3% | GPT-5.5 |
| CyberGym | 68.7% | 81.8% | GPT-5.5 |
| Claw-Eval | 62.3% | Coming soon | Coming soon |
| Gert Labs | 60.11% | 72.93% | GPT-5.5 |
| ResearchClawBench | 18.2% | 17.0% | GLM-5.1 |
| Terminal-Bench 2.1 (Vals) | 56.9% | 76.4% | GPT-5.5 |
| OSWorld-Verified | Coming soon | 78.7% | Coming soon |
| Toolathlon | Coming soon | 55.6% | Coming soon |
| τ²-bench results | Coming soon | 98% | Coming soon |
| OSWorld 2.0 | Coming soon | 13.0% | Coming soon |
| JobBench | Coming soon | 42.7% | Coming soon |
| ExploitGym | Coming soon | 13.4% | Coming soon |

### Coding

- Winner: GPT-5.5
- GLM-5.1 public-lane score: 56.8 (Supported · #39/183)
- GPT-5.5 public-lane score: 67.7 (Supported · #8/183)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 58.4% | 58.6% | GPT-5.5 |
| NL2Repo | 42.7% | Coming soon | Coming soon |
| SWE-Rebench | 62.7% | Coming soon | Coming soon |
| Vibe Code Bench | 31.46% | 69.85% | GPT-5.5 |
| OpenHarmony Bench | 52.3% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 81.4% | 85.3% | GPT-5.5 |
| SWE-bench (Vals) | 76.4% | 82.6% | GPT-5.5 |
| Terminal-Bench 2.0 | Coming soon | 82.0% | Coming soon |
| React Native Evals | Coming soon | 84.7% | Coming soon |
| cursorBench31 | Coming soon | 59.2% | Coming soon |
| cursorBench32 | Coming soon | 58.4% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 43.0% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- GLM-5.1 public-lane score: Coming soon
- GPT-5.5 public-lane score: 71.3 (#19/48)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | Coming soon | 81.2% | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 83.2% | Coming soon |
| OfficeQA Pro | Coming soon | 54.1% | Coming soon |

### Reasoning

- Winner: Coming soon
- GLM-5.1 public-lane score: 69.9 (Unranked · 2 rankable rows)
- GPT-5.5 public-lane score: 63.5 (#15/22)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| MRCR v2 64K-128K | Coming soon | 83.1% | Coming soon |
| MRCR v2 128K-256K | Coming soon | 87.5% | Coming soon |
| ARC-AGI-2 | Coming soon | 85% | Coming soon |
| ARC-AGI-3 | Coming soon | 0.4% | Coming soon |

### Knowledge

- Winner: GPT-5.5
- GLM-5.1 public-lane score: 55.4 (Supported · #59/181)
- GPT-5.5 public-lane score: 73.3 (Supported · #7/181)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | 86.2% | 93.6% | GPT-5.5 |
| HLE | 52.3% | 52.2% | GLM-5.1 |
| GPQA Diamond (Vals) | 84.5% | 93.2% | GPT-5.5 |
| MMLU-Pro (Vals) | 86.9% | 88.1% | GPT-5.5 |
| GPQA | Coming soon | 93.6% | Coming soon |
| HLE w/o tools | Coming soon | 41.4% | Coming soon |

### Instruction Following

- Winner: Coming soon
- GLM-5.1 public-lane score: 93.5 (#5/120)
- GPT-5.5 public-lane score: 92.9 (#7/120)

### Mathematics

- Winner: Coming soon
- GLM-5.1 public-lane score: 64.1 (#3/7)
- GPT-5.5 public-lane score: 69.6 (Unranked · 3 rankable rows)

| Benchmark | GLM-5.1 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | 95.3% | Coming soon | Coming soon |
| HMMT Nov 2025 | 94.0% | Coming soon | Coming soon |
| HMMT Feb 2026 | 82.6% | Coming soon | Coming soon |
| MMAnswerBench | 83.8% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 33.448% | 51.700% | GPT-5.5 |
| FrontierMath v2 (Tier 4) | 12.500% | 35.400% | GPT-5.5 |
| FrontierMath (legacy) | Coming soon | 51.7% | Coming soon |

## FAQ

### Which is better overall, GLM-5.1 or GPT-5.5?

GPT-5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between GLM-5.1 and GPT-5.5?

The widest category gap is in knowledge, where the averages are 55.4 for GLM-5.1 and 73.3 for GPT-5.5.

### How many benchmarks does GLM-5.1 cover on BenchLM?

GLM-5.1 currently has 26 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.5 cover on BenchLM?

GPT-5.5 currently has 38 sourced benchmark scores on BenchLM.

## Related Comparisons

- [GLM-5.1 vs GLM-5.3](/compare/glm-5-1-vs-glm-5-3)
- [GPT-5.5 vs GLM-5.3](/compare/glm-5-3-vs-gpt-5-5)
- [GLM-5.1 vs GLM-5.2](/compare/glm-5-1-vs-glm-5-2)
- [GPT-5.5 vs GLM-5.2](/compare/glm-5-2-vs-gpt-5-5)

## Explore More

- [GLM-5.1 profile](/models/glm-5-1)
- [GPT-5.5 profile](/models/gpt-5-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)