GPT-5.6 Terra vs Grok 4.5
GPT-5.6 Terra and Grok 4.5 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. GPT-5.6 Terra has a 1.1M context window — about 2× the 500k of Grok 4.5. GPT-5.6 Terra leads on long-context retrieval, multilingual, vision.
Specs side by side
| Metric | OpenAI GPT-5.6 Terra | xAI Grok 4.5 |
|---|---|---|
| Input price (per 1M) | $2.5 | $2 |
| Output price (per 1M) | $15 | $6 |
| Context window | 1.1M tokens | 500k tokens |
| Speed tier | balanced | balanced |
| Open weights | No | No |
| EU region | Yes | No |
| Free tier | No | No |
| Prompt caching | Yes | Yes |
| Vision input | Yes | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose GPT-5.6 Terra if…
- You need 1.1M context (2× more than Grok 4.5)
- EU data residency is required
- HIPAA eligibility is required
- Long-context retrieval is central to your workload
- Multilingual is central to your workload
Choose Grok 4.5 if…
- Cost is a priority ($2 / $6 per 1M vs $2.5 / $15 per 1M)
Benchmark delta
GPT-5.6 Terra leads on
- Long-context retrieval
- Multilingual
- Vision
Grok 4.5 leads on
Grok 4.5 has no meaningful benchmark lead in this pair.
FAQ — GPT-5.6 Terra vs Grok 4.5
GPT-5.6 Terra vs Grok 4.5 — which is better?
GPT-5.6 Terra and Grok 4.5 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. GPT-5.6 Terra has a 1.1M context window — about 2× the 500k of Grok 4.5. GPT-5.6 Terra leads on long-context retrieval, multilingual, vision. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does GPT-5.6 Terra pricing compare to Grok 4.5?
GPT-5.6 Terra costs $2.5 / $15 per 1M vs Grok 4.5 at $2 / $6 per 1M. Grok 4.5 is cheaper on output tokens by roughly 150%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does GPT-5.6 Terra or Grok 4.5 have the bigger context window?
GPT-5.6 Terra has a 1.1M-token context window — 2× the 500k context of Grok 4.5. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for GPT-5.6 Terra or Grok 4.5?
GPT-5.6 Terra: no — Free $5 credit for new accounts; paid thereafter. Grok 4.5: no — X Premium / SuperGrok includes Grok web chat; API is paid.
Which is better for coding — GPT-5.6 Terra or Grok 4.5?
Grok 4.5 leads on coding benchmarks (GPT-5.6 Terra: 93/100, Grok 4.5: 94/100). For production coding agents also weigh tool-use performance — GPT-5.6 Terra scores 93, Grok 4.5 scores 92.