OpenAI
GPT-5.6 Luna
GPT-5.6 Luna is a OpenAI model with 1.05M context, $0.20 in / $1.20 out per million tokens, last verified October 1, 2026. Open weights: no. Status: Superseded since September 22, 2026; the current pick is GPT-6 Luna. Public-board scores are linked to the publisher; vendor-only figures stay in the watch-out, not on the board.
OpenAI’s GPT-5.6 budget tier, succeeded by GPT-6 Luna on September 22. The newer model halves input pricing ($0.20→$0.10) and lowers output pricing from $1.20 to $0.50.
Recorded profile verification October 1, 2026Individual provider fields may change
| Specification | GPT-5.6 Luna |
|---|---|
| Provider | OpenAI |
| Tier | Budget |
| Context window | 1.05M |
| Max output | 128K |
| Input / 1M tokens | $0.20 |
| Output / 1M tokens | $1.20 |
| Weights | Closed |
| Parameters | Not verifiedUnverified |
| Reasoning levels | none, low, medium, high, xhigh, max |
| Modalities | text, image |
| API model id | gpt-5.6-luna |
| Released | July 9, 2026 |
Pricing tiers: Launch $1/$6, reduced to $0.20/$1.20 on July 30. Above 272K input the full request bills $0.40/$1.80. Cached input $0.02; cache writes $0.25 at short context. Batch $0.10/$0.60 at short context. Regional/FedRAMP processing adds 10% where eligible.
Publisher evidence
Published benchmark results
Each result keeps its source date visible. Dates refer to source publication or capture unless the source explicitly states when it measured the result. A missing benchmark is not treated as a zero.
| Benchmark | Score | Source date | Source |
|---|---|---|---|
| Terminal-Bench 2.1Vendor launch table; complete common run settings unverifiedCross-model comparability not verified | 84.7% | 2026-07-09 | OpenAI GPT-5.6 launch table (vendor-reported; effort and experiment date unspecified) · View source |
| LiveBench | 73.6% | 2026-09-05 | LiveBench official leaderboard (benchmark-owned), max effort · View source |
Best for
- Classification
- High-volume chat
- Latency-sensitive pipelines
Watch out
History
GPT-5.6 Luna timeline
Release and status events for this model that passed two-source verification — dated, sourced, and linked.
- GPT-5.6 LunaGeneral availabilityJuly 9, 2026
General availability began after the limited preview.
OpenAI API changelog (Jul 9 2026) - GPT-5.6 LunaLimited previewJune 26, 2026
Fast, lower-cost GPT-5.6 tier included in the initial limited preview.
OpenAI preview announcement
Source receipts
Catalog figures for this model were checked against the following sources.
- OpenAI model card — whole-profile source check October 1 (accessed 2026-10-01)
- OpenAI current API pricing and processing tiers (accessed 2026-10-01)
- OpenAI — GPT-5.6 (accessed 2026-08-29)
- OpenAI API pricing (gpt-5.6-luna $0.20/$1.20) (accessed 2026-08-29)
- OpenAI — Introducing GPT-6 Sol and Luna (GPT-5.6 Luna successor) (accessed 2026-09-26)
Common questions
GPT-5.6 Luna
Answered from the verified figures on this page rather than general guidance.