# GPT-5.5 Pro vs Grok 4.5

> Side-by-side benchmark comparison for GPT-5.5 Pro and Grok 4.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-pro-vs-grok-4-5
- Last updated: October 7, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.5 Pro and Grok 4.5 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.
- Grok 4.5 has the lower published output-token price.
- GPT-5.5 Pro has the larger published context window at 1M.

## Model Snapshot

| Property | GPT-5.5 Pro | Grok 4.5 |
|----------|----------|----------|
| Creator | OpenAI | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 500K |
| Independent public score (not head-to-head) | 72.9 | 63.97 |
| Benchmarks Covered | 8 | 17 |
| Pricing (input/output) | $30.00 / $180.00 | $2.00 / $6.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.5 public-lane score: 57.6 (Supported · #29/122)

| Benchmark | GPT-5.5 Pro | Grok 4.5 | Winner |
|-----------|-----------|-----------|--------|
| BrowseComp | 90.1% | Coming soon | Coming soon |
| Terminal-Bench 3.0 | Coming soon | 15.7% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 83.3% | Coming soon |
| deepSwe | Coming soon | 53% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 67.8% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.5 public-lane score: 57.7 (Supported · #27/146)

| Benchmark | GPT-5.5 Pro | Grok 4.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | Coming soon | 64.7% | Coming soon |
| SWE Multilingual | Coming soon | 78% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 83.3% | Coming soon |
| CursorBench 3.2 | Coming soon | 66.7% | Coming soon |
| VulcanBench v3 | Coming soon | 89.9% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 87.4% | Coming soon |
| SWE-bench (Vals) | Coming soon | 86.6% | Coming soon |
| PostTrainBench v1.1 | Coming soon | 23.4% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 75.1 (Unranked · 3 rankable rows)
- Grok 4.5 public-lane score: 50.4 (#28/28)

| Benchmark | GPT-5.5 Pro | Grok 4.5 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 95.00% | 85.67% | GPT-5.5 Pro |
| ARC-AGI-2 | 84.2% | 52.6% | GPT-5.5 Pro |
| ARC-AGI-3 | Coming soon | 0.3% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.5 public-lane score: 79.5 (Unranked · 1 rankable row)

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.5 public-lane score: 67 (Supported · #19/174)

| Benchmark | GPT-5.5 Pro | Grok 4.5 | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.2% | Coming soon | Coming soon |
| HLE w/o tools | 43.1% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 92.9% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 89.2% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 70.1 (Unranked · 3 rankable rows)
- Grok 4.5 public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Grok 4.5 | 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 |

## FAQ

### Is there enough evidence to pick between GPT-5.5 Pro and Grok 4.5?

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)
- [Grok 4.5 vs GPT-5.5](/compare/gpt-5-5-vs-grok-4-5)
- [GPT-5.5 Pro vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-5-5-pro)
- [Grok 4.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-grok-4-5)

## Explore More

- [GPT-5.5 Pro profile](/models/gpt-5-5-pro)
- [Grok 4.5 profile](/models/grok-4-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)