Compare / head-to-head
GPT-5vsGPT-5.6 Luna
GPT-5.6 Luna leads 4 of 5 shared benchmarks. GPT-5.6 Luna is 8x 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
1 – 4
GPT-5.6 Luna leads
Cheaper per token
GPT-5.6 Luna
8x cheaper, input + output
Larger context
GPT-5.6 Luna
1.1M tokens
Provider uptime (30d)
95.107%
OpenAI
GPT-5
OpenAI · released 2025-08-07
textvision
GPT-5.6 Luna
OpenAI · released 2026-07-09
textvision
Quality
Benchmark matrix
5 shared · 3 only GPT-5 · 2 only GPT-5.6 Luna| Benchmark | GPT-5 | GPT-5.6 Luna | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 86.2% ↗epoch | 92.3% ↗ | -6.1 pt | GPT-5.6 Luna |
| FrontierMath Tier 4 v2 (Epoch AI run) | 22% ↗epoch | 61% ↗epoch | -39 pt | GPT-5.6 Luna |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 55.4% ↗epoch | 82.1% ↗epoch | -26.7 pt | GPT-5.6 Luna |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 91.4% ↗epoch | 98.3% ↗epoch | -6.9 pt | GPT-5.6 Luna |
| SimpleQA Verified | 50.1% ↗epoch | 41% ↗epoch | +9.1 pt | GPT-5 |
| Only GPT-5 reports · 3 | ||||
| SWE-bench Verified | 74.9% ↗ | not reported | — | — |
| AIME 2025 | 94.6% ↗ | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 73.6% ↗epoch | not reported | — | — |
| Only GPT-5.6 Luna reports · 2 | ||||
| DeepSWE v1.1 | not reported | 67.2% ↗ | — | — |
| SWE-Bench Pro | not reported | 62.7% ↗ | — | — |
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 minus GPT-5.6 Luna 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 | GPT-5.6 Luna | Edge |
|---|---|---|---|
| Context window | 400K tokens | 1.1M tokens | GPT-5.6 Luna |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $1.25 ↗ | $0.2 ↗ | GPT-5.6 Luna |
| Output price / 1M | $10 ↗ | $1.2 ↗ | GPT-5.6 Luna |
| Cached input / 1M | $0.125 ↗ | $0.02 ↗ | GPT-5.6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $11.25 | $1.4 | GPT-5.6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2025-08-07 | 2026-07-09 | — |
| Cited benchmark scores | 9 | 8 | — |
Reliability
OpenAI status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GPT-5 vs …
Models sharing the most benchmarksMore matchups
GPT-5.6 Luna vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GPT-5 and GPT-5.6 Luna on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.