GPT-5.5 vs Grok 4.1 Fast
Head to head on 25 shared benchmarks, with price, context window, and release dates.
Benchmark scores
59evals · sort by any column, ⤢ to expand fullscreen
| Model | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.5 OpenAI | 68.4% | 1844elo | 78.2 | 76.8% | 13.7% | 46.1% | 84.7% | 82.5% | 81.1% | 73.0% | 87.7% | 96.3% | 87.7% | 92.8% | 49.1% | 86.9% | 88.6% | 68.8% | 50.0% | 51.5% | 47.3% | 75.0% | 49.2% | 69.8% | 69.3% | - | - | 86.2% | 54.2% | 12.9% | 36.2% | 86.0% | 90.0% | 100.0% | 1315elo | 34.0% | 51.8% | 5.7% | 51.7% | 44.8% | 24.9% | 1769elo | 15.1% | - | 51.8% | - | - | 2.1% | - | - | 78.7% | 45.3% | 100.0% | 4.2 | 58.6% | 75.7% | 83.4% | 57.4% | 68.1% | 61.9% |
| Grok 4.1 Fast xAI | 66.0% | 1324elo | 40.1 | 63.7% | 5.1% | 36.5% | 64.7% | 69.6% | 52.2% | 28.2% | 74.3% | 83.7% | 80.2% | 60.8% | 28.1% | 78.7% | 74.3% | 42.6% | 4.0% | 31.3% | 29.6% | 73.1% | 14.4% | 1.2% | 63.7% | 62.0% | 34.3% | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 11.8 | - | 35.0% | 80.2% | - | 39.9% | 100.0% | - | - | - | - | - | - | - | - | - | 51.0% |
2 / 2 models
| Attribute | GPT-5.5 OpenAI | Grok 4.1 Fast xAI |
|---|---|---|
| Description | GPT-5.5 is an AI model from OpenAI. | Grok 4.1 Fast is an AI model from xAI. |
| Family | GPT | Grok |
| Params | - | - |
| Open weights | closed | closed |
| License | proprietary | proprietary |
| Released | 23 Apr 2026 | 19 Nov 2025 |
| Context | 1,050,000 | - |
| Input $/1M | $5.00 | - |
| Output $/1M | $30.00 | - |
| Cache read $/1M | $0.500 | - |
| Cache write $/1M | - | - |
| Speed | 0 tok/s | 0 tok/s |
| Latency | 0.00 s | 0.00 s |
| Modalities | file, image, text | text |
| Providers | - | - |
| Publisher | OpenAI | xAI |
| Reported scores | GPQA Diamond76.8% (AA) Humanity's Last Exam (HLE)13.7% (AA) IFBench46.1% (AA) SciCode47.3% (AA) τ²-bench (Tau²-bench)69.3% (AA) | Infraresolutionbench80.2% (150 samples) Agent Diff Bench62.0% (179 samples) Medpt100.0% (15 samples) Hanabi11.8 (15 samples) SciCode29.6% (AA) |
FAQ
- Is GPT-5.5 or Grok 4.1 Fast better?
- Across the 25 benchmarks both models report on Sophon, GPT-5.5 leads on 25 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
- How do GPT-5.5 and Grok 4.1 Fast compare on GPQA Diamond?
- GPT-5.5 scores 76.8% and Grok 4.1 Fast scores 63.7% on GPQA Diamond.
- When were GPT-5.5 and Grok 4.1 Fast released?
- GPT-5.5 was released 23 Apr 2026 by OpenAI. Grok 4.1 Fast was released 19 Nov 2025 by xAI.
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