When was GPT-5.6 Luna released?

GPT-5.6 Luna was released by OpenAI on Friday, Jun 26 2026.

Who made GPT-5.6 Luna?

GPT-5.6 Luna was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

How much does GPT-5.6 Luna cost?

GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens through the OpenAI API. Cached input is $0.02 per million tokens. Those are the rates for the “Up to 272K input tokens” tier; 1 other pricing tier is published for this model. Rates are pay-as-you-go API prices verified against OpenAI's published pricing on August 18, 2026.

What benchmark scores did GPT-5.6 Luna get?

GPT-5.6 Luna reports 13 tracked benchmark scores — BullshitBench v2: 41%; Gray Swan IPI (k = 1): 8.3%; Gray Swan IPI (k = 10): 38.6%; Gray Swan IPI (k = 15): 43.9%; CursorBench 4.0: 35.9%; Supabase Evals (with skills): 63.8%; Supabase Evals (no skills): 42%; Frontier-Bench v0.1: 14.3%; Terminal-Bench 4.0: 17.27%; Terminal-Bench 2.1: 82.5%; BrowseComp: 83.3%; ARC-AGI-2: 59.54%; threejseval: 1274. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.

Is GPT-5.6 Luna open source?

No. GPT-5.6 Luna is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

What came before and after GPT-5.6 Luna?

OpenAI's previous tracked release was GPT-5.6 Terra on Jun 26 2026. It was followed by GPT-5.6-Cyber on Aug 10 2026.

GPT-5.6 Luna

Released Jun 26 2026

GPT-5.6 Luna is an AI model released by OpenAI on Friday, Jun 26 2026, the same day as GPT-5.6 Terra. Benchmark results (shown below) cover BullshitBench v2, Gray Swan IPI, CursorBench 4.0, Supabase Evals, Frontier-Bench v0.1, Terminal-Bench 4.0, and 4 more.

API pricing

Up to 272K input tokens

Input: $0.20
Cached input: $0.02
Cache write: $0.25
Output: $1.20

Over 272K input tokens

Input: $0.40
Cached input: $0.04
Cache write: $0.50
Output: $1.80

Reasoning or thinking is supported.

USD per 1M tokensModel mapping

Available from


OpenAI	—	flex	$0.10	$0.60	1M
OpenAI	—	—	$0.20	$1.20	1M
Azure	—	—	$0.20	$1.20	1M
Azure	eu	—	$0.22	$1.32	1M
Azure	us	—	$0.22	$1.32	1M
Amazon Bedrock	us-east-1	—	$0.22	$1.32	1M
OpenAI	—	fast	$0.40	$2.40	1M

USD per 1M tokens

Benchmarks

Coding

CursorBench 4.0via CursorBench

35.9%

#11 of 13

Supabase Evals

63.8%with skills

42%no skills

with skills

#11 of 11

no skills

#11 of 11

Terminal & CLI

Frontier-Bench v0.1

14.3%

#8 of 9

Terminal-Bench 4.0via Terminal-Bench

17.27%

#18 of 21

Terminal-Bench 2.1

82.5%

#17 of 32

Agentic & tool use

BrowseCompvia BenchLM

83.3%

#17 of 28

Reasoning & science

ARC-AGI-2via BenchLM

59.54%

#23 of 34

Robustness

BullshitBench v2

41%

#42 of 84

Gray Swan IPI

8.3%k = 1

38.6%k = 10

43.9%k = 15

k = 1

#10 of 13

k = 10

#10 of 13

k = 15

#11 of 14

Community preference

threejseval

1274

#16 of 18

Source: CursorBench, retrieved 28 September 2026 · Source: BenchLM, retrieved 31 August 2026 · Source: Terminal-Bench, retrieved 30 August 2026. Other sources are identified on the linked benchmark pages.

Compare GPT-5.6 Luna with

GPT-5.6 Luna

Suggested comparisons

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Frequently asked questions

: GPT-5.6 Luna was released by OpenAI on Friday, Jun 26 2026.
: GPT-5.6 Luna was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.
: GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens through the OpenAI API. Cached input is $0.02 per million tokens. Those are the rates for the “Up to 272K input tokens” tier; 1 other pricing tier is published for this model. Rates are pay-as-you-go API prices verified against OpenAI's published pricing on August 18, 2026.
: GPT-5.6 Luna reports 13 tracked benchmark scores — BullshitBench v2: 41%; Gray Swan IPI (k = 1): 8.3%; Gray Swan IPI (k = 10): 38.6%; Gray Swan IPI (k = 15): 43.9%; CursorBench 4.0: 35.9%; Supabase Evals (with skills): 63.8%; Supabase Evals (no skills): 42%; Frontier-Bench v0.1: 14.3%; Terminal-Bench 4.0: 17.27%; Terminal-Bench 2.1: 82.5%; BrowseComp: 83.3%; ARC-AGI-2: 59.54%; threejseval: 1274. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.
: No. GPT-5.6 Luna is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
: OpenAI's previous tracked release was GPT-5.6 Terra on Jun 26 2026. It was followed by GPT-5.6-Cyber on Aug 10 2026.