Head to head
GPT-5.6 Sol vs Grok 4.3
GPT-5.6 Sol (OpenAI) and Grok 4.3 (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 4.3 |
|---|---|---|
| Intelligence (AA index) | — | 38 |
| Output speed (tokens/sec) | — | 129.3 |
| Context window | 1.1M ✓ | 1M |
| Max output | 128K | 1M ✓ |
| Input price / 1M | $5 | $1.25 ✓ |
| Output price / 1M | $30 | $2.5 ✓ |
| Released | 2026-07-09 | 2026-04 |
Choose GPT-5.6 Sol if you want…
- Larger context window (1.1M)
Choose Grok 4.3 if you want…
- Lower price ($1.56 / 1M blended)
Grok 4.3
Grok 4.3 made a deliberate trade: xAI stopped chasing frontier performance and built something more practical instead. The result is a model that earns its keep through native X/Twitter integration — pulling posts seconds old when news breaks — and a 1 million token context window that handles entire codebases or lengthy regulatory documents in a single pass. At $1.25 per million input tokens, it arrives 40-60% cheaper than its predecessor Grok-4, and users find real value in its DeepSearch mode, which combines live web data with X discussions in a way that rivals Perplexity for current-events research. Frontend developers report genuinely polished web UI output, moving past the "cheap AI demo" look. The honest trade-off: creative writers consistently find it too literal and verbose, and its 16-second time-to-first-token sits at the high end for reasoning models in this price range. If your work is anchored in real-time information or long-document analysis rather than narrative craft, Grok 4.3 offers a focused, cost-sensible tool.
Full Grok 4.3 details →FAQ
Which is better, GPT-5.6 Sol or Grok 4.3?
GPT-5.6 Sol leads on 1 of the headline metrics (larger context window (1.1m)), while Grok 4.3 wins on lower price ($1.56 / 1m blended). The right pick depends on whether you prioritise capability, speed, or cost.
Is GPT-5.6 Sol or Grok 4.3 cheaper?
Grok 4.3 is cheaper at $1.56 per 1M tokens (blended), versus $11.25.
Can I use both GPT-5.6 Sol and Grok 4.3?
Yes. Both are available on just4o.chat from a single chat — you can switch between them per message with no separate subscriptions.