Compare / head-to-head
GPT-5.6 LunavsGrok 4.3
GPT-5.6 Luna leads 5 of 5 shared benchmarks. GPT-5.6 Luna is 2.7x cheaper per token. GPT-5.6 Luna has the larger context window (1.1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
5 – 0
GPT-5.6 Luna leads
Cheaper per token
GPT-5.6 Luna
2.7x cheaper, input + output
Larger context
GPT-5.6 Luna
1.1M tokens
Provider uptime (30d)
95.3216% · —
OpenAI · xAI
GPT-5.6 Luna
OpenAI · released 2026-07-09
textvision
Quality
Benchmark matrix
5 shared · 2 only GPT-5.6 Luna · 1 only Grok 4.3| Benchmark | GPT-5.6 Luna | Grok 4.3 | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 92.3% ↗ | 88.8% ↗epoch | +3.5 pt | GPT-5.6 Luna |
| FrontierMath Tier 4 v2 (Epoch AI run) | 61% ↗epoch | 14.6% ↗epoch | +46.4 pt | GPT-5.6 Luna |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 82.1% ↗epoch | 42.8% ↗epoch | +39.3 pt | GPT-5.6 Luna |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.3% ↗epoch | 93.3% ↗epoch | +5 pt | GPT-5.6 Luna |
| SimpleQA Verified | 41% ↗epoch | 33.2% ↗epoch | +7.8 pt | GPT-5.6 Luna |
| Only GPT-5.6 Luna reports · 2 | ||||
| DeepSWE v1.1 | 67.2% ↗ | not reported | — | — |
| SWE-Bench Pro | 62.7% ↗ | not reported | — | — |
| Only Grok 4.3 reports · 1 | ||||
| LMArena Elo | not reported | 1397.7 ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is GPT-5.6 Luna minus Grok 4.3 in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | GPT-5.6 Luna | Grok 4.3 | Edge |
|---|---|---|---|
| Context window | 1.1M tokens | 1M tokens | GPT-5.6 Luna |
| Max output | 128K tokens | — | — |
| Input price / 1M | $0.2 ↗ | $1.25 ↗ | GPT-5.6 Luna |
| Output price / 1M | $1.2 ↗ | $2.5 ↗ | GPT-5.6 Luna |
| Cached input / 1M | $0.02 ↗ | $0.2 ↗ | GPT-5.6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $1.4 | $3.75 | GPT-5.6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-07-09 | — | — |
| Cited benchmark scores | 8 | 6 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GPT-5.6 Luna vs …
Models sharing the most benchmarksMore matchups
Grok 4.3 vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GPT-5.6 Luna and Grok 4.3 on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.