token.app › Compare › GPT-5.1 vs Grok 4.5
GPT-5.1 vs Grok 4.5
Grok 4.5 leads on 3 of 3 shared benchmarks. Grok 4.5 is 1.1× cheaper per token on a blended 3:1 basis. Grok 4.5 accepts the larger context window (500K).
Head to head
Blended price uses a 3:1 input:output mix
| GPT-5.1 | Grok 4.5 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Input $/1M | $1.25 | $2.00 |
| Output $/1M | $10.00 | $6.00 |
| Blended $/1M | $3.44 | $3.00 |
| Context window | 400K | 500K |
| Max output | 128K | — |
| Released | Nov 2025 | Jul 2026 |
| Licence | Proprietary | Proprietary |
| GPQA Diamond | 87.6% | 93.4% |
| SimpleQA Verified | 48.9% | 53.5% |
| OTIS Mock AIME | 88.6% | 97.8% |
Benchmark scores independently run and published by Epoch AI, 'AI Benchmarking Hub', used under CC BY 4.0. Only benchmarks with a score for BOTH models are compared.
Choose GPT-5.1 if…
- No clear advantage on the data we hold.
Choose Grok 4.5 if…
- Costs less per token — $3.00 vs $3.44 blended
- Higher GPQA Diamond (93.4% vs 87.6%)
- Higher SimpleQA Verified (53.5% vs 48.9%)
- Higher OTIS Mock AIME (97.8% vs 88.6%)
- Larger context window (500K)
- Newer model (released Jul 2026)
FAQ
Which is better, GPT-5.1 or Grok 4.5?
Across the 3 benchmarks both models have independently-run scores for, GPT-5.1 leads on 0 and Grok 4.5 leads on 3. Benchmarks are one input — price and context window are on this page too.
Is GPT-5.1 cheaper than Grok 4.5?
Grok 4.5 is cheaper: $3.00 versus $3.44 per million tokens blended at 3:1 input:output. Input alone: $1.25 vs $2.00. Output alone: $10.00 vs $6.00.
What context windows do GPT-5.1 and Grok 4.5 have?
GPT-5.1: 400,000 tokens. Grok 4.5: 500,000 tokens.
Who makes GPT-5.1 and Grok 4.5?
GPT-5.1 is made by OpenAI. Grok 4.5 is made by xAI.