# Composer 2.5 vs GPT-5.5

> Side-by-side benchmark comparison for Composer 2.5 and GPT-5.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/composer-2-5-vs-gpt-5-5
- Last updated: October 2, 2026

- Shared sourced benchmarks: 6
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick GPT-5.5 if you want the stronger benchmark profile. Composer 2.5 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 69.4 to 61.
- The biggest single benchmark swing is Terminal-Bench 2.1 (Vals) in Agentic, with scores of 58.4% and 76.4%.
- Composer 2.5 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 | Composer 2.5 | GPT-5.5 |
|----------|----------|----------|
| Creator | Cursor | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 200K | 1M |
| Overall Score | null | 69.4 |
| Benchmarks Covered | 8 | 40 |
| Pricing (input/output) | $0.50 / $2.50 | $5.00 / $30.00 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 59.9 (Supported · #22/119)

| Benchmark | Composer 2.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 69.3% | 82% | GPT-5.5 |
| Terminal-Bench 2.1 (Vals) | 58.4% | 76.4% | GPT-5.5 |
| CyberGym | Coming soon | 81.8% | Coming soon |
| BrowseComp | Coming soon | 84.4% | Coming soon |
| OSWorld-Verified | Coming soon | 78.7% | Coming soon |
| MCP Atlas | Coming soon | 75.3% | Coming soon |
| Toolathlon | Coming soon | 55.6% | Coming soon |
| τ²-bench results | Coming soon | 98% | Coming soon |
| Gert Labs | Coming soon | 72.93% | Coming soon |
| ResearchClawBench | Coming soon | 17.0% | 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 |
| ApprenticeBench | Coming soon | 20% | Coming soon |

### Coding

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 62.7 (Supported · #13/144)

| Benchmark | Composer 2.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 69.3% | 82.0% | GPT-5.5 |
| SWE Multilingual | 79.8% | Coming soon | Coming soon |
| cursorBench31 | 63.2% | 59.2% | Composer 2.5 |
| CursorBench 3.2 | 56.1% | 58.4% | GPT-5.5 |
| SWE-bench (Vals) | 79.6% | 82.6% | GPT-5.5 |
| CursorBench 4.0 | 27.7% | Coming soon | Coming soon |
| SWE-bench Pro | Coming soon | 58.6% | Coming soon |
| Vibe Code Bench | Coming soon | 69.85% | Coming soon |
| React Native Evals | Coming soon | 84.7% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 43.0% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 85.3% | Coming soon |
| PostTrainBench v1.1 | Coming soon | 27.2% | Coming soon |

### Reasoning

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 66.2 (#17/27)

| Benchmark | Composer 2.5 | 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 |

### Multimodal & Grounded

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 71.4 (#19/49)

| Benchmark | Composer 2.5 | 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 |

### Knowledge

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 69.4 (Supported · #15/171)

| Benchmark | Composer 2.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | Coming soon | 93.6% | Coming soon |
| GPQA-D | Coming soon | 93.6% | Coming soon |
| HLE | Coming soon | 52.2% | Coming soon |
| HLE w/o tools | Coming soon | 41.4% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 93.2% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 88.1% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 91.9 (#7/125)

### Mathematics

- Winner: Not comparable
- Composer 2.5 public-lane score: Coming soon
- GPT-5.5 public-lane score: 69.4 (Unranked · 3 rankable rows)

| Benchmark | Composer 2.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | Coming soon | 51.7% | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 51.700% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 35.400% | Coming soon |

## FAQ

### Which is better overall, Composer 2.5 or GPT-5.5?

GPT-5.5 is ahead overall on BenchLM right now.

### How many benchmarks does Composer 2.5 cover on BenchLM?

Composer 2.5 currently has 8 sourced benchmark scores on BenchLM.

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

GPT-5.5 currently has 40 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Composer 2.5 vs Composer 2](/compare/composer-2-vs-composer-2-5)
- [GPT-5.5 vs Composer 2](/compare/composer-2-vs-gpt-5-5)
- [Composer 2.5 vs Composer 2 Fast](/compare/composer-2-5-vs-composer-2-fast)
- [GPT-5.5 vs Composer 2 Fast](/compare/composer-2-fast-vs-gpt-5-5)

## Explore More

- [Composer 2.5 profile](/models/composer-2-5)
- [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)