GPT-5.5 Pro vs Grok 4.6
GPT-5.5 Pro 
Grok 4.6 Verdict
- GPT-5.5 Pro (xhigh) and Grok 4.6 (medium) are level on quality (67.1 vs 66.2).
- GPT-5.5 Pro (xhigh) is stronger in maths, reasoning.
- Grok 4.6 (medium) is stronger in agents & tools, coding, composite, knowledge, long context.
- Grok 4.6 (medium) is 23× cheaper ($3.00 vs $67.50 per 1M blended).
- Grok 4.6 (medium) streams 14.2× faster (57 vs 4 tokens per second).
| Metric | GPT-5.5 Pro (xhigh) | Grok 4.6 (medium) |
|---|---|---|
| BenchLeader Index | 67.1 | 66.2 |
| Maths score | 74.5 | – |
| Reasoning score | 80.1 | 67.7 |
| Agents & tools score | – | 73.3 |
| Coding score | – | 64.1 |
| Composite score | – | 83.6 |
| Knowledge score | – | 77.6 |
| Long context score | – | 67.0 |
| Blended price $/M | $67.50 | $3.00 |
| Output speed | 4 tok/s | 57 tok/s |
| Time to first answer | 3.5 s | 34.1 s |
| Context window | 1.1M | 500k |
| FrontierMath Tiers 1–3 | 87.7% | – |
| FrontierMath Tier 4 | 78.0% | – |
| SciCode | – | 54.6% |
| AA Intelligence Index | – | 43.0 |
| AA-LCR | – | 81.0% |
| AA-Omniscience | – | 28 |
| GPQA Diamond (AA) | – | 93.5% |
| Humanity's Last Exam (AA) | – | 42.1% |
| SciCode (AA) | – | 55.9% |
| ARC-AGI-1 | 95.0% | 87.5% |
| ARC-AGI-2 | 84.2% | 61.3% |
| CritPt | 30.6% | 17.7% |
| GDPval (AA) | – | 57.1% |
| τ²-Bench Banking (AA) | – | 44.3% |
| DeepSWE | – | 67.5% |
| LMCA | 53.9% | – |
| DTBench | 96.0% | – |
| CursorBench | – | 67.1% |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
GPT-5.5 Pro vs Grok 4.6: questions
- Is GPT-5.5 Pro better than Grok 4.6?
- GPT-5.5 Pro (xhigh) and Grok 4.6 (medium) are level on quality (67.1 vs 66.2). The BenchLeader Index combines every independent quality benchmark; GPT-5.5 Pro (xhigh) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Which is cheaper, GPT-5.5 Pro or Grok 4.6?
- Grok 4.6 is cheaper: $3.00 against $67.50 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.5 Pro or Grok 4.6?
- Grok 4.6 streams faster: 57 against 4 output tokens per second.
- Which has the larger context window?
- GPT-5.5 Pro accepts more context: 1.1M against 500k tokens.