GPT-5.6 Terra vs Grok 4.5
Pricing verdict: GPT-5.6 Terra vs Grok 4.5: Grok 4.5 is cheaper for input-heavy usage ($2.00/M vs $2.50/M input tokens), while GPT-5.6 Terra is better for long-context tasks (1,050,000 tokens).
Direct answer: choose Grok 4.5 for lower token spend and choose GPT-5.6 Terra when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.6 Terra
Grok 4.5
Cost Differences
Grok 4.5 costs less than GPT-5.6 Terra
Quick Recommendation
Winner for direct API pricing: Grok 4.5. At the default workload, Grok 4.5 saves about $15.00/month ($182.50/year) versus GPT-5.6 Terra.
Feature Comparison
| Feature | GPT-5.6 Terra | Grok 4.5 |
|---|---|---|
| Provider | OpenAI | xAI |
| Input Price | $2.50/1M tokens | $2.00/1M tokens |
| Output Price | $15.00/1M tokens | $6.00/1M tokens |
| Context Window | 1,050,000 tokens | 500,000 tokens |
| Max Output | 128,000 tokens | 131,072 tokens |
| Category | balanced | flagship |
| Capabilities | textvisioncodereasoning | textvisioncodereasoning |
| Release Date | 6/26/2026 | 7/8/2026 |
GPT-5.6 Terra vs Grok 4.5: Which Should You Choose?
Choosing between GPT-5.6 Terra and Grok 4.5 depends on your priorities: cost efficiency, context length, or raw capability. Grok 4.5 is the more affordable option at $2.00/1M input tokens — 20% cheaper than GPT-5.6 Terra. Meanwhile, GPT-5.6 Terra offers a significantly larger context window at 1,050,000 tokens vs 500,000 for Grok 4.5.
These models come from different providers — OpenAI and xAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to xAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: GPT-5.6 Terra is a balanced model while Grok 4.5 is flagship. This means they're optimized for different workloads. Grok 4.5 targets more demanding workloads, while GPT-5.6 Terra provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.6 Terra charges $15.00/1M output tokens vs $6.00 for Grok 4.5. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Grok 4.5 has the edge here at $6.00/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose GPT-5.6 Terra when:
- • You need a larger context window (1,050,000 tokens)
- • You're already using OpenAI's API ecosystem
Choose Grok 4.5 when:
- • Budget is a primary concern
- • You need longer outputs (up to 131,072 tokens)
- • You're already using xAI's API ecosystem
Pros and Caveats at a Glance
GPT-5.6 Terra
- • Input pricing: $2.50/M tokens
- • Output pricing: $15.00/M tokens
- • Context window: 1,050,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Higher input cost than Grok 4.5
- • Higher output cost than Grok 4.5
Grok 4.5
- • Input pricing: $2.00/M tokens
- • Output pricing: $6.00/M tokens
- • Context window: 500,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Smaller context window than GPT-5.6 Terra
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.6 Terra (OpenAI)
Grok 4.5 (xAI)
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Which is cheaper, GPT-5.6 Terra or Grok 4.5?▼
What is the context window difference between GPT-5.6 Terra and Grok 4.5?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare OpenAI and xAI API pricing beyond this model matchup?▼
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