GPT-5.6 Luna vs Grok 4.3
GPT-5.6 Luna leads on 2 of 3 benchmarks where both are measured. Specs, per-token pricing, and live benchmark scores — refreshed daily from our benchmark database.
Specs & pricing
| GPT-5.6 Luna | Grok 4.3 | |
|---|---|---|
| Company | OpenAI | xAI |
| Released | Jul 2026 | Jul 2026 |
| Context window | 1.0M | 1.0M |
| Input /1M tokens | $1 | $1.25 |
| Output /1M tokens | $6 | $2.5 |
| Open weights | No | No |
Benchmarks
| Benchmark | GPT-5.6 Luna | Grok 4.3 |
|---|---|---|
| Arena Elo | — | 1442 Elo |
| GPQA | 91.1% | 90.1% |
| Hallucination Rate (lower is better) | 87.7% | 74.5% |
| SWE-bench Verified | 93.0% | — |
| Speed (tok/s) | 184 tok/s | 113 tok/s |
Scores come from published leaderboards and official model cards (sources listed on the benchmarks page) and refresh daily. Pricing via vendor pages and OpenRouter.