# GPT-5.5 Pro vs Hy4 preview

> Side-by-side benchmark comparison for GPT-5.5 Pro and Hy4 preview across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-pro-vs-hy4-preview
- Last updated: September 18, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.5 Pro and Hy4 preview share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Hy4 preview has the lower published output-token price.

## Model Snapshot

| Property | GPT-5.5 Pro | Hy4 preview |
|----------|----------|----------|
| Creator | OpenAI | Tencent |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Independent public score (not head-to-head) | 61.9 | 60.89 |
| Benchmarks Covered | 6 | 28 |
| Pricing (input/output) | $30.00 / $180.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 58.9 (Estimated · #28/154)
- Hy4 preview public-lane score: 58.6 (Estimated · #30/154)

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| BrowseComp | 90.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 85.4% | Coming soon |
| CyberGym | Coming soon | 78.4% | Coming soon |
| WideResearch | Coming soon | 83.9% | Coming soon |
| DRACO | Coming soon | 77.2% | Coming soon |
| MCP Atlas | Coming soon | 83.7% | Coming soon |
| Toolathlon-Verified | Coming soon | 74.1% | Coming soon |
| APEX-Agents | Coming soon | 37.1% | Coming soon |
| skillsBench | Coming soon | 62.9% | Coming soon |
| JobBench | Coming soon | 61.7% | Coming soon |
| Agents' Last Exam | Coming soon | 22.8% | Coming soon |
| AutomationBench | Coming soon | 32.1% | Coming soon |
| BankerToolBench | Coming soon | 78.6% | Coming soon |
| HLE w/ tools | Coming soon | 55.4% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Hy4 preview public-lane score: 59.4 (Estimated · #24/154)

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | Coming soon | 85.4% | Coming soon |
| SWE-bench Pro | Coming soon | 65.7% | Coming soon |
| SWE Multilingual | Coming soon | 82.9% | Coming soon |
| DeepSWE | Coming soon | 64.3% | Coming soon |
| NL2Repo | Coming soon | 58.9% | Coming soon |
| ProgramBench | Coming soon | 17.5% | Coming soon |
| PostTrain Bench | Coming soon | 35.6% | Coming soon |
| sweMarathon | Coming soon | 31.9% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Hy4 preview public-lane score: 84.9 (Unranked · 1 rankable row)

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | Coming soon | 66.2% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Hy4 preview public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| CritPt | Coming soon | 16.9% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 59.4 (Estimated · #38/184)
- Hy4 preview public-lane score: 56.8 (Estimated · #45/184)

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.2% | 55.4% | GPT-5.5 Pro |
| HLE w/o tools | 43.1% | 43.4% | Hy4 preview |
| GPQA | Coming soon | 92.3% | Coming soon |
| GPQA-D | Coming soon | 92.3% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 70.1 (Unranked · 3 rankable rows)
- Hy4 preview public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Hy4 preview | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 52.4% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 51.000% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 39.600% | Coming soon | Coming soon |
| Apex | Coming soon | 74.2% | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.5 Pro and Hy4 preview?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-5.5 Pro vs GPT-5.5](/compare/gpt-5-5-vs-gpt-5-5-pro)
- [Hy4 preview vs GPT-5.5](/compare/gpt-5-5-vs-hy4-preview)
- [GPT-5.5 Pro vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gpt-5-5-pro)
- [Hy4 preview vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-hy4-preview)

## Explore More

- [GPT-5.5 Pro profile](/models/gpt-5-5-pro)
- [Hy4 preview profile](/models/hy4-preview)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)