Compare / head-to-head
GPT-5.6 TerravsGPT-6 Luna
GPT-5.6 Terra leads 1 of 1 shared benchmark. GPT-6 Luna is 23.3x 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
1 – 0
GPT-5.6 Terra leads
Cheaper per token
GPT-6 Luna
23.3x cheaper, input + output
Larger context
Tie
both 1.1M tokens
Providers
OpenAI
same provider
GPT-5.6 Terra
OpenAI · released 2026-07-09
textvision
GPT-6 Luna
OpenAI · released 2026-09-22
textvision
Quality
Benchmark matrix
1 shared · 6 only GPT-5.6 Terra · 0 only GPT-6 Luna| Benchmark | GPT-5.6 Terra | GPT-6 Luna | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 1 | ||||
| DeepSWE v1.1 | 69.6% ↗ | 66.6% ↗ | +3 pt | GPT-5.6 Terra |
| Only GPT-5.6 Terra reports · 6 | ||||
| GPQA Diamond | 92.9% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 70.7% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 86% ↗epoch | not reported | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 99.7% ↗epoch | not reported | — | — |
| SimpleQA Verified | 43.2% ↗epoch | not reported | — | — |
| SWE-Bench Pro | 63.4% ↗ | not reported | — | — |
| Only GPT-6 Luna reports · 0 | ||||
| GPT-6 Luna reports nothing GPT-5.6 Terra does not. | ||||
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 Terra minus GPT-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-5.6 Terra | GPT-6 Luna | Edge |
|---|---|---|---|
| Context window | 1.1M tokens | 1.1M tokens | Tie |
| Max output | 128K tokens | 128K tokens | Tie |
| Input price / 1M | $2 ↗ | $0.1 ↗ | GPT-6 Luna |
| Output price / 1M | $12 ↗ | $0.5 ↗ | GPT-6 Luna |
| Cached input / 1M | $0.2 ↗ | $0.01 ↗ | GPT-6 Luna |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $14 | $0.6 | GPT-6 Luna |
| Modalities | text · vision | text · vision | Tie |
| Released | 2026-07-09 | 2026-09-22 | — |
| Cited benchmark scores | 8 | 1 | — |
Reliability
OpenAI status
Live from /statusMore matchups
GPT-5.6 Terra vs …
Models sharing the most benchmarksMore matchups
GPT-6 Luna vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GPT-5.6 Terra and GPT-6 Luna on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.