token.app › Compare › GPT-5.5 vs Grok 4.5
GPT-5.5 vs Grok 4.5
GPT-5.5 and Grok 4.5 split the 4 shared benchmarks evenly. Grok 4.5 is 3.8× cheaper per token on a blended 3:1 basis. GPT-5.5 accepts the larger context window (1.1M).
Head to head
Blended price uses a 3:1 input:output mix
| GPT-5.5 | Grok 4.5 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Input $/1M | $5.00 | $2.00 |
| Output $/1M | $30.00 | $6.00 |
| Blended $/1M | $11.25 | $3.00 |
| Context window | 1.1M | 500K |
| Max output | 128K | — |
| Released | Apr 2026 | Jul 2026 |
| Licence | Proprietary | Proprietary |
| GPQA Diamond | 90.7% | 93.4% |
| FrontierMath T1–3 | 85.3% | 57.2% |
| FrontierMath T4 | 72.5% | 24.4% |
| OTIS Mock AIME | 84.4% | 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-5.5 if…
- Higher FrontierMath T1–3 (85.3% vs 57.2%)
- Higher FrontierMath T4 (72.5% vs 24.4%)
- Larger context window (1.1M)
Choose Grok 4.5 if…
- Costs less per token — $3.00 vs $11.25 blended
- Higher GPQA Diamond (93.4% vs 90.7%)
- Higher OTIS Mock AIME (97.8% vs 84.4%)
- Newer model (released Jul 2026)
FAQ
Which is better, GPT-5.5 or Grok 4.5?
Across the 4 benchmarks both models have independently-run scores for, GPT-5.5 leads on 2 and Grok 4.5 leads on 2. Benchmarks are one input — price and context window are on this page too.
Is GPT-5.5 cheaper than Grok 4.5?
Grok 4.5 is cheaper: $3.00 versus $11.25 per million tokens blended at 3:1 input:output. Input alone: $5.00 vs $2.00. Output alone: $30.00 vs $6.00.
What context windows do GPT-5.5 and Grok 4.5 have?
GPT-5.5: 1,050,000 tokens. Grok 4.5: 500,000 tokens.
Who makes GPT-5.5 and Grok 4.5?
GPT-5.5 is made by OpenAI. Grok 4.5 is made by xAI.