# Claude Opus 5.5 vs GLM-5.1

> Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 47.6 on the Noometry Index. GLM-5.1 costs 3.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-5-5-vs-glm-5-1
- Last updated: 2026-10-10
- Shared benchmarks: 22

## Summary

- They share 22 benchmarks with published results for both. Claude Opus 5.5 scores higher in 9 categories and GLM-5.1 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 5.5 leads 92.4 to 49.0.
- The biggest single-benchmark swing is ProofBench: 100% for Claude Opus 5.5 and 22.2% for GLM-5.1.
- GLM-5.1 is cheaper at $1.40 / $4.40 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
- Claude Opus 5.5 accepts more context: 1M tokens versus 200K.
- GLM-5.1 has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| Provider | Anthropic | Z.ai (Zhipu) |
| Noometry Index | 68.5 | 47.6 |
| Rank | 3 | 51 |
| Context | 1M | 200K |
| Input $/M | $4 | $1.40 |
| Output $/M | $20 | $4.40 |
| Weights | Proprietary | Open |

## Coding

- Claude Opus 5.5: 71.4 (#1)
- GLM-5.1: 48.5 (#52)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| LMArena WebDev | 1820 | 1509 |
| SciCode | 66.9% | 43.8% |
| LMArena Coding | 1545 | 1486 |
| SWE-bench Verified | — | 74.2% |
| FrontierCode | 54.4% | — |
| CursorBench | 57.8% | — |
| FrontierSWE | 62.3% | — |
| WeirdML | — | 57.1% |
| MirrorCode | 77.4% | — |
| ALE-Bench | — | 887.1 |

## Agentic & Tool Use

- Claude Opus 5.5: 45.3 (#13)
- GLM-5.1: 24.8 (#106)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| APEX-Agents | 73.5% | 40.9% |
| ExploitBench | — | 18.1% |
| GBAEval | — | 0% |
| GDP.pdf | 30.6% | — |
| Vending-Bench 2 | — | 5,634 |

## Reasoning

- Claude Opus 5.5: 79.5 (#2)
- GLM-5.1: 38.2 (#57)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| NYT Connections (extended) | 88.5% | 77.7% |
| CritPt | 31.7% | 4.6% |
| LMArena Hard Prompts | 1545 | 1472 |
| ARC-AGI-2 | 92.5% | — |
| SimpleBench | — | 55.1% |
| ARC-AGI-1 | 97.5% | — |
| Chess Puzzles | — | 19% |
| Thematic Generalization | — | 69.8% |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| DTBench | 98.9% | — |
| LMCA | 68.2% | — |
| Epoch Capabilities Index | — | 149.86 |

## Math

- Claude Opus 5.5: 92.4 (#2)
- GLM-5.1: 49.0 (#48)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 91.2% | 36.8% |
| OTIS Mock AIME 2024-2025 | 100% | 93.3% |
| ProofBench | 100% | 22.2% |
| FrontierMath Tier 4 | 95% | — |
| MathArena Final-Answer Competitions | — | 67.1% |
| LMArena Math | — | 1472 |
| FrontierMath (Feb 2025 set) | — | 33.4% |
| FrontierMath Tier 4 (v1) | — | 12.5% |

## Knowledge

- Claude Opus 5.5: 66.6 (#9)
- GLM-5.1: 55.0 (#45)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| GPQA Diamond | 90.6% | 89.9% |
| SimpleQA Verified | 72.2% | 34% |
| LMArena Expert | 1564 | 1477 |

## Multimodal

- Claude Opus 5.5: 56.5 (#2)
- GLM-5.1: —

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| Furniture Assembly | 83.3% | — |

## Multilingual

- Claude Opus 5.5: 59.8 (#1)
- GLM-5.1: 55.2 (#34)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| LMArena Non-English | 1513 | 1448 |
| LMArena Chinese | 1572 | 1516 |
| LMArena Russian | 1532 | 1453 |
| LMArena French | — | 1478 |
| LMArena German | — | 1466 |
| LMArena Japanese | — | 1436 |
| LMArena Korean | — | 1423 |
| LMArena Spanish | — | 1467 |

## Instruction Following

- Claude Opus 5.5: 80.1 (#2)
- GLM-5.1: 76.5 (#41)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| LMArena Instruction Following | 1535 | 1451 |

## Long Context

- Claude Opus 5.5: 47.3 (#18)
- GLM-5.1: 44.9 (#51)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| LMArena Longer Query | 1540 | 1467 |

## Writing & Preference

- Claude Opus 5.5: 78.7 (#3)
- GLM-5.1: 67.2 (#29)

| Benchmark | Claude Opus 5.5 | GLM-5.1 |
|---|---|---|
| LMArena Text | 1518 | 1462 |
| LMArena Creative Writing | 1538 | 1454 |
| EQ-Bench Creative Writing | 2050 | 1592 |
| LMArena Multi-Turn | 1520 | 1473 |

## FAQ

### Is Claude Opus 5.5 better than GLM-5.1?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 47.6 on the Noometry Index. GLM-5.1 costs 3.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 5.5 or GLM-5.1?

GLM-5.1 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

### Is Claude Opus 5.5 or GLM-5.1 better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 48.5 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 200K.

### How many benchmarks do Claude Opus 5.5 and GLM-5.1 share?

22 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and GLM-5.1 has 41.