GPT-5.6 Sol vs Grok 4.6
Both are Flagship-tier models, from OpenAI and xAI respectively. Grok 4.6 is the cheaper choice overall at a 4:1 input:output ratio.
Which is cheaper
Side by side
| Spec | GPT-5.6 Sol | Grok 4.6 |
|---|---|---|
| Provider | OpenAI | xAI |
| Tier | Flagship | Flagship |
| Context window | 1.05M | 500K |
| Max output | 128K | — |
| Input $/1M | $4.00 | $2.00 |
| Output $/1M | $20.00 | $6.00 |
| Cache read $/1M | $0.40 | $0.50 |
| Cache write $/1M | $5.00 | — |
| Modalities | text, image | text, image |
GPT-5.6 Sol. Short-context rate, for prompts up to 272K input tokens. Above 272K the rate is $8 input / $30 output, cache read $0.80, cache write $10 per 1M. Promotional pricing, stated to run at least through 21 November 2026.
Grok 4.6. Short-context rate, for prompts under 200K tokens. At 200K and above: $4 input / $12 output, cache read $1 per 1M. xAI's Priority Processing tier doubles every rate and applies to all models — it is not a separate model.
Sources
GPT-5.6 Sol — verified August 29, 2026
Grok 4.6 — verified August 29, 2026
Full GPT-5.6 Sol pricing page → · Full Grok 4.6 pricing page →