Compare / head-to-head
GPT-5.4vsGPT-5.6 Luna
GPT-5.6 Luna leads 4 of 6 shared benchmarks. GPT-5.6 Luna is 12.5x 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
2 – 4
GPT-5.6 Luna leads
Cheaper per token
GPT-5.6 Luna
12.5x cheaper, input + output
Larger context
Tie
both 1.1M tokens
Provider uptime (30d)
95.092%
OpenAI
GPT-5.4
OpenAI · released 2026-03-05
textvision
GPT-5.6 Luna
OpenAI · released 2026-07-09
textvision
Quality
Benchmark matrix
6 shared · 14 only GPT-5.4 · 1 only GPT-5.6 Luna| Benchmark | GPT-5.4 | GPT-5.6 Luna | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 6 | ||||
| GPQA Diamond | 92.8% ↗ | 92.3% ↗ | +0.5 pt | GPT-5.4 |
| FrontierMath Tier 4 v2 (Epoch AI run) | 49% ↗epoch | 61% ↗epoch | -12 pt | GPT-5.6 Luna |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 78.6% ↗epoch | 82.1% ↗epoch | -3.5 pt | GPT-5.6 Luna |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 97.8% ↗epoch | 98.3% ↗epoch | -0.5 pt | GPT-5.6 Luna |
| SimpleQA Verified | 45.1% ↗epoch | 41% ↗epoch | +4.1 pt | GPT-5.4 |
| SWE-Bench Pro | 57.7% ↗ | 62.7% ↗ | -5 pt | GPT-5.6 Luna |
| Only GPT-5.4 reports · 14 | ||||
| AIME 2026 | 99.2% ↗matharena ⚠ | not reported | — | — |
| Humanity's Last Exam (no tools) | 39.8% ↗ | not reported | — | — |
| LMArena Elo | 1452.6 ↗ | not reported | — | — |
| BrowseComp | 82.7% ↗ | not reported | — | — |
| GDPval (wins or ties) | 83% ↗ | not reported | — | — |
| Humanity's Last Exam (with tools) | 52.1% ↗ | not reported | — | — |
| MCP Atlas | 67.2% ↗ | not reported | — | — |
| MMMU-Pro (no tools) | 81.2% ↗ | not reported | — | — |
| MMMU-Pro (with tools) | 82.1% ↗ | not reported | — | — |
| OSWorld-Verified | 75% ↗ | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 76.9% ↗epoch | not reported | — | — |
| Tau2-bench Telecom | 98.9% ↗ | not reported | — | — |
| Terminal-Bench 2.0 | 75.1% ↗ | not reported | — | — |
| Toolathlon | 54.6% ↗ | not reported | — | — |
| Only GPT-5.6 Luna reports · 1 | ||||
| DeepSWE v1.1 | not reported | 67.2% ↗ | — | — |
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-5.4 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-5.4 | GPT-5.6 Luna | Edge |
|---|---|---|---|
| Context window | 1.1M tokens | 1.1M tokens | Tie |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $2.5 ↗ | $0.2 ↗ | GPT-5.6 Luna |
| Output price / 1M | $15 ↗ | $1.2 ↗ | GPT-5.6 Luna |
| Cached input / 1M | $0.25 ↗ | $0.02 ↗ | GPT-5.6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $17.5 | $1.4 | GPT-5.6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-03-05 | 2026-07-09 | — |
| Cited benchmark scores | 21 | 8 | — |
Reliability
OpenAI status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GPT-5.4 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-5.4 and GPT-5.6 Luna on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.