Head to head
GPT-5.6 Sol vs Grok 4.5
GPT-5.6 Sol (OpenAI) and Grok 4.5 (xAI) compared on intelligence, speed, context, and price — and which to choose. Both run on just4o.chat from one chat.
| Metric | GPT-5.6 Sol | Grok 4.5 |
|---|---|---|
| Intelligence (AA index) | — | — |
| Output speed (tokens/sec) | — | — |
| Context window | 1.1M ✓ | 500K |
| Max output | 128K | — |
| Input price / 1M | $5 | $2 ✓ |
| Output price / 1M | $30 | $6 ✓ |
| Released | 2026-07-09 | 2026-07-08 |
Choose GPT-5.6 Sol if you want…
- Larger context window (1.1M)
Choose Grok 4.5 if you want…
- Lower price ($3 / 1M blended)
FAQ
Which is better, GPT-5.6 Sol or Grok 4.5?
GPT-5.6 Sol leads on 1 of the headline metrics (larger context window (1.1m)), while Grok 4.5 wins on lower price ($3 / 1m blended). The right pick depends on whether you prioritise capability, speed, or cost.
Is GPT-5.6 Sol or Grok 4.5 cheaper?
Grok 4.5 is cheaper at $3 per 1M tokens (blended), versus $11.25.
Can I use both GPT-5.6 Sol and Grok 4.5?
Yes. Both are available on just4o.chat from a single chat — you can switch between them per message with no separate subscriptions.