GPT-5.6 Luna vs Grok 4.3
GPT-5.6 Luna is ~52% cheaper than Grok 4.3 on output tokens. Both are capability tier 5. GPT-5.6 Luna has the larger context window.
| GPT-5.6 Luna | Grok 4.3 | |
|---|---|---|
| Vendor | OpenAI | xAI |
| Capability tier | 5/8 | 5/8 |
| Size class | FAST | BALANCED |
| Parameters | — | — |
| Context window | 1,050,000 ✓ | 1,000,000 |
| Input $/M | $0.20 | $1.25 |
| Output $/M | $1.20 ✓ | $2.50 |
| Cached input $/M | $0.10 | $0.20 |
Which should you choose?
Both sit at capability tier 5, so GPT-5.6 Luna is usually the better value at ~52% lower output cost, and it also carries the larger 1,050,000-token context window. Because they're the same tier, benchmark both on your own prompts before committing — list price rarely predicts task quality.
FAQ
Is GPT-5.6 Luna cheaper than Grok 4.3?
GPT-5.6 Luna is the cheaper of the two on output tokens ($1.20/M vs $2.50/M), about 52% less.
GPT-5.6 Luna vs Grok 4.3: which has a bigger context window?
GPT-5.6 Luna has the larger context window (1,050,000 tokens).
Which is more capable, GPT-5.6 Luna or Grok 4.3?
Both sit at the same capability tier (5/8) — pick on price, context, or benchmark them on your prompts.
GPT-5.6 Luna or Grok 4.3: which should I use?
Both sit at capability tier 5, so GPT-5.6 Luna is usually the better value at ~52% lower output cost, and it also carries the larger 1,050,000-token context window. Because they're the same tier, benchmark both on your own prompts before committing — list price rarely predicts task quality.
How much more does GPT-5.6 Luna cost than Grok 4.3?
At 10M input + 10M output tokens per month, GPT-5.6 Luna runs about $14.00 and Grok 4.3 about $37.50 — a difference of $23.50 per month at that volume.
Settle it on your own prompts
List prices only go so far — benchmark GPT-5.6 Luna and Grok 4.3 on your actual workload for measured cost, latency and quality.
Pricing and specs maintained by Mintok's catalog watchers from public sources. Not investment advice. Methodology.