# Claude Sonnet 5.5 vs GLM-5.3-Flash

> Side-by-side benchmark comparison for Claude Sonnet 5.5 and GLM-5.3-Flash across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-5-vs-glm-5-3-flash
- Last updated: September 28, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Claude Sonnet 5.5 if you want the stronger benchmark profile. GLM-5.3-Flash only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 5.5 leads overall 80.49 to 60.62.
- The clearest category separation is in coding, where the averages are 79.6 for Claude Sonnet 5.5 and 52.4 for GLM-5.3-Flash.
- The biggest single benchmark swing is Chartography (tools) in Multimodal & Grounded, with scores of 90.2% and 78.0%.
- GLM-5.3-Flash is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Sonnet 5.5 | GLM-5.3-Flash |
|----------|----------|----------|
| Creator | Anthropic | Z.AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Overall Score | 80.49 | 60.62 |
| Benchmarks Covered | 47 | 19 |
| Pricing (input/output) | $2.00 / $10.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Claude Sonnet 5.5
- Claude Sonnet 5.5 public-lane score: 66.1 (Supported · #10/111)
- GLM-5.3-Flash public-lane score: 55.8 (Supported · #27/111)

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 70.60% | Coming soon | Coming soon |
| HLE w/ tools | 64.5% | 55.3% | Claude Sonnet 5.5 |
| DRACO | 87.0% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 59.9% | Coming soon | Coming soon |
| LAB all-pass (Harvey held-out) | 10.0% | Coming soon | Coming soon |
| LAB criterion-pass (Harvey held-out) | 93.1% | Coming soon | Coming soon |
| Toolathlon Verified Pass@3 | 85.2% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 68.5% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 31.6 turns | Coming soon | Coming soon |
| AutomationBench (Zapier 1.0.6) | 44.7% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | 78.4% | GLM-5.3-Flash |
| Terminal-Bench 2.1 | Coming soon | 84.3% | Coming soon |
| AutomationBench | Coming soon | 48.8% | Coming soon |
| Agents' Last Exam | Coming soon | 26.3% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 62.9% | Coming soon |

### Coding

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 79.6 (Estimated · #3/136)
- GLM-5.3-Flash public-lane score: 52.4 (Supported · #33/136)

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 46.2% | Coming soon | Coming soon |
| cursorBench40 | 55.5% | Coming soon | Coming soon |
| SWE-bench Pro | 81.3% | Coming soon | Coming soon |
| SWE Multilingual | 90.3% | Coming soon | Coming soon |
| SWE Multimodal | 54.3% | Coming soon | Coming soon |
| DeepSWE | 71.0% | 63.4% | Claude Sonnet 5.5 |
| FrontierCode 1.1 Extended | 59.1% | Coming soon | Coming soon |
| ProgramBench | 79.7% | Coming soon | Coming soon |
| FrontierSWE v2 | 61.9% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 84.3% | Coming soon |
| NL2Repo | Coming soon | 56.3% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 80.5% | Coming soon |
| SWE-bench (Vals) | Coming soon | 92.0% | Coming soon |
| OpenHarmony Bench | Coming soon | 57.3% | Coming soon |

### Reasoning

- Winner: Directional only
- Claude Sonnet 5.5 public-lane score: 79.2 (#7/27)
- GLM-5.3-Flash public-lane score: 77.3 (#10/27)

### Multimodal & Grounded

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: 83.3 (Unranked · 7 rankable rows)
- GLM-5.3-Flash public-lane score: 80.4 (#12/50)

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| Chartography (no tools) | 61.6% | Coming soon | Coming soon |
| Chartography (tools) | 90.2% | 78.0% | Claude Sonnet 5.5 |
| BenchCAD Vision2Code (no tools) | 0.747 | Coming soon | Coming soon |
| BenchCAD Vision2Code (tools) | 0.963 | Coming soon | Coming soon |
| Biomedical image analysis | 72.2% | Coming soon | Coming soon |
| OfficeQA | 76.9% | Coming soon | Coming soon |
| OfficeQA Pro | 65.6% | 62.4% | Claude Sonnet 5.5 |
| CharXiv | Coming soon | 89.4% | Coming soon |
| BabyVision | Coming soon | 53.4% | Coming soon |
| MMVU | Coming soon | 80.5% | Coming soon |

### Knowledge

- Winner: Claude Sonnet 5.5
- Claude Sonnet 5.5 public-lane score: 80.9 (Supported · #6/160)
- GLM-5.3-Flash public-lane score: 60.8 (Supported · #35/160)

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| HealthBench (raw) | 69.4% | Coming soon | Coming soon |
| HealthBench (length-adjusted) | 65.4% | Coming soon | Coming soon |
| HealthBench Professional (raw) | 77.1% | Coming soon | Coming soon |
| HealthBench Professional | 69.2% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 89.2% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 44.7% | Coming soon | Coming soon |
| SpatialBench Verified | 72.5% | Coming soon | Coming soon |
| SingleCellBench | 59.1% | Coming soon | Coming soon |
| Protein Design | 51.0% | Coming soon | Coming soon |
| Morphology-to-molecule matching | 25.0% | Coming soon | Coming soon |
| Medicinal chemistry | 65.3% | Coming soon | Coming soon |
| Protein Design library ranking | 54.8% | Coming soon | Coming soon |
| De novo protein-binder design | 82.3% | Coming soon | Coming soon |
| Protocols (troubleshooting) | 67.3% | Coming soon | Coming soon |
| Protocols (understanding) | 66.6% | Coming soon | Coming soon |
| HLE w/o tools | 56.9% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 86.4% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 86.1% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: Coming soon
- GLM-5.3-Flash public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | 92.1% | Coming soon | Coming soon |
| MILU | 91.6% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Sonnet 5.5 public-lane score: Coming soon
- GLM-5.3-Flash public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | GLM-5.3-Flash | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | 86.8% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (tools) | 95.2% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 5.5 or GLM-5.3-Flash?

Claude Sonnet 5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 5.5 and GLM-5.3-Flash?

The widest category gap is in coding, where the averages are 79.6 for Claude Sonnet 5.5 and 52.4 for GLM-5.3-Flash.

### How many benchmarks does Claude Sonnet 5.5 cover on BenchLM?

Claude Sonnet 5.5 currently has 47 sourced benchmark scores on BenchLM.

### How many benchmarks does GLM-5.3-Flash cover on BenchLM?

GLM-5.3-Flash currently has 19 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5.5 vs GLM-5.3](/compare/claude-sonnet-5-5-vs-glm-5-3)
- [GLM-5.3-Flash vs GLM-5.3](/compare/glm-5-3-vs-glm-5-3-flash)
- [Claude Sonnet 5.5 vs GLM-5.2](/compare/claude-sonnet-5-5-vs-glm-5-2)
- [GLM-5.3-Flash vs GLM-5.2](/compare/glm-5-2-vs-glm-5-3-flash)

## Explore More

- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [GLM-5.3-Flash profile](/models/glm-5-3-flash)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)