# GPT-5.5 Pro vs Grok 4.1 Fast

> Side-by-side benchmark comparison for GPT-5.5 Pro and Grok 4.1 Fast across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-pro-vs-grok-4-1-fast
- Last updated: September 4, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for GPT-5.5 Pro and Grok 4.1 Fast.

## Summary

- GPT-5.5 Pro and Grok 4.1 Fast do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | GPT-5.5 Pro | Grok 4.1 Fast |
|----------|----------|----------|
| Creator | OpenAI | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Non-Reasoning |
| Context | 1M | 1M |
| Independent public score (not head-to-head) | 63.07 | 49.8 |
| Benchmarks Covered | 6 | 1 |
| Pricing (input/output) | $30.00 / $180.00 | $0.20 / $0.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 60.6 (Estimated · #24/151)
- Grok 4.1 Fast public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Grok 4.1 Fast | Winner |
|-----------|-----------|-----------|--------|
| BrowseComp | 90.1% | Coming soon | Coming soon |
| Gert Labs | Coming soon | 47.32% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.1 Fast public-lane score: 47.5 (Estimated · #88/183)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.1 Fast public-lane score: 31.3 (Unranked · 1 rankable row)

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.1 Fast public-lane score: 41.7 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 61.1 (Estimated · #36/181)
- Grok 4.1 Fast public-lane score: 42.1 (Estimated · #130/181)

| Benchmark | GPT-5.5 Pro | Grok 4.1 Fast | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.2% | Coming soon | Coming soon |
| HLE w/o tools | 43.1% | Coming soon | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: Coming soon
- Grok 4.1 Fast public-lane score: 41.8 (#99/120)

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.5 Pro public-lane score: 70.2 (Unranked · 3 rankable rows)
- Grok 4.1 Fast public-lane score: Coming soon

| Benchmark | GPT-5.5 Pro | Grok 4.1 Fast | 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

### Can I compare GPT-5.5 Pro and Grok 4.1 Fast on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [GPT-5.5 Pro vs GPT-5.5](/compare/gpt-5-5-vs-gpt-5-5-pro)
- [Grok 4.1 Fast vs GPT-5.5](/compare/gpt-5-5-vs-grok-4-1-fast)
- [GPT-5.5 Pro vs Grok 4.1 Fast (Reasoning)](/compare/gpt-5-5-pro-vs-grok-4-1-fast-reasoning)
- [Grok 4.1 Fast vs Grok 4.1 Fast (Reasoning)](/compare/grok-4-1-fast-vs-grok-4-1-fast-reasoning)

## Explore More

- [GPT-5.5 Pro profile](/models/gpt-5-5-pro)
- [Grok 4.1 Fast profile](/models/grok-4-1-fast)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)