Compare / head-to-head
GPT-5.6 LunavsGPT-6 Astra
GPT-6 Astra leads 5 of 5 shared benchmarks. GPT-5.6 Luna is 42.9x cheaper per token. Both offer a 1.1M-token context window.
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 5
GPT-6 Astra leads
Cheaper per token
GPT-5.6 Luna
42.9x cheaper, input + output
Larger context
Tie
both 1.1M tokens
Provider uptime (30d)
95.2096%
OpenAI
GPT-5.6 Luna
OpenAI · released 2026-07-09
textvision
GPT-6 Astra
OpenAI · released 2026-09-03
textvision
Quality
Benchmark matrix
5 shared · 2 only GPT-5.6 Luna · 2 only GPT-6 Astra| Benchmark | GPT-5.6 Luna | GPT-6 Astra | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 92.3% ↗ | 96% ↗ | -3.7 pt | GPT-6 Astra |
| FrontierMath Tier 4 v2 (Epoch AI run) | 61% ↗epoch | 97.6% ↗epoch | -36.6 pt | GPT-6 Astra |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 82.1% ↗epoch | 93.7% ↗epoch | -11.6 pt | GPT-6 Astra |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.3% ↗epoch | 100% ↗epoch | -1.7 pt | GPT-6 Astra |
| SimpleQA Verified | 41% ↗epoch | 75.6% ↗epoch | -34.6 pt | GPT-6 Astra |
| Only GPT-5.6 Luna reports · 2 | ||||
| DeepSWE v1.1 | 67.2% ↗ | not reported | — | — |
| SWE-Bench Pro | 62.7% ↗ | not reported | — | — |
| Only GPT-6 Astra reports · 2 | ||||
| AutomationBench | not reported | 41.4% ↗ | — | — |
| Terminal-Bench Science 0.1 | not reported | 64.6% ↗ | — | — |
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 GPT-6 Astra 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 | GPT-6 Astra | Edge |
|---|---|---|---|
| Context window | 1.1M tokens | 1.1M tokens | Tie |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $0.2 ↗ | $10 ↗ | GPT-5.6 Luna |
| Output price / 1M | $1.2 ↗ | $50 ↗ | GPT-5.6 Luna |
| Cached input / 1M | $0.02 ↗ | $1 ↗ | GPT-5.6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $1.4 | $60 | GPT-5.6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-07-09 | 2026-09-03 | — |
| Cited benchmark scores | 8 | 8 | — |
Reliability
OpenAI status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GPT-5.6 Luna vs …
Models sharing the most benchmarksMore matchups
GPT-6 Astra 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 GPT-6 Astra on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.