GPT-6 Luna is a member of OpenAI's GPT-6 family positioned for high-volume, low-cost, well‑defined tasks (e.g., summarization, extraction, quick Q&A). It was announced in late September 2026 and is offered via API, Amazon Bedrock, ChatGPT (various channels) and the ChatGPT desktop app.
CURRENT SNAPSHOT4/5 DIMENSIONS WITH DATA
The dimensions that change the decision.
PRICING
Pricing and cost relative to predecessorAnnounced at roughly half the token price of the GPT-5.6 Sol/Luna predecessors. Reporting gives Luna's list prices as $0.10 per million input tokens and $0.50 per million output tokens. OpenAI attributes lower API prices to caching and inference improvements; articles also report a broader 50% price cut vs the 5.6 series and additional prompt-caching discounts for GPT-6.
Price change versus previous generationReportedly priced at about half the token price of the GPT-5.6 Sol and Luna models (≈50% reduction reported).
CONTEXT WINDOW
Not established from the available sources.
MODALITIES
Supported modalities / runtime usageReportedly used to run ChatGPT Voice: OpenAI's voice feature runs on GPT-6 Astra, Sol, and Luna and can access plugins like email, calendar, and Slack (i.e., Luna is used for voice interactions in ChatGPT's feature set).
BENCHMARKS
Reported benchmark/performance change versus predecessorOne report states Luna 'improves on its predecessor by 5.4 percentage points while costing 58 percent less' on the evaluations referenced by that coverage; the excerpt does not name the specific benchmark.
AVAILABILITY
Availability and distribution channelsReportedly available on Amazon Bedrock (generally available). Also offered in ChatGPT Work and Codex for paid accounts; Luna is available in the ChatGPT desktop app and for Free and Go users; offered via the API as gpt-6-luna, with rollout in the ChatGPT app described as gradual.
Availability in ChatGPT clientsAt launch, Luna is reported to be available in the ChatGPT desktop app and to Free and Go users; broader ChatGPT availability was described as rolling out gradually.
OTHER · Primary intended tasks (examples)DEVELOPER CLAIM
Described as suited to clerical, high-volume tasks with clear goals — e.g., summarizing documents, extracting information, and answering quick questions.
OTHER · Role in high-volume workloadsDEVELOPER CLAIM
Positioned to make focused, repeatable tasks practical at high volume, where small differences in latency and cost multiply across requests.
AVAILABILITY · Availability and distribution channelsDEVELOPER CLAIM
Reportedly available on Amazon Bedrock (generally available). Also offered in ChatGPT Work and Codex for paid accounts; Luna is available in the ChatGPT desktop app and for Free and Go users; offered via the API as gpt-6-luna, with rollout in the ChatGPT app described as gradual.
AVAILABILITY · Availability in ChatGPT clientsDEVELOPER CLAIM
At launch, Luna is reported to be available in the ChatGPT desktop app and to Free and Go users; broader ChatGPT availability was described as rolling out gradually.
OTHER · API identifierDEVELOPER CLAIM
Provided in the API under the name gpt-6-luna.
PRICING · Pricing and cost relative to predecessorDEVELOPER CLAIM
Announced at roughly half the token price of the GPT-5.6 Sol/Luna predecessors. Reporting gives Luna's list prices as $0.10 per million input tokens and $0.50 per million output tokens. OpenAI attributes lower API prices to caching and inference improvements; articles also report a broader 50% price cut vs the 5.6 series and additional prompt-caching discounts for GPT-6.
PRICING · Price change versus previous generationDEVELOPER CLAIM
Reportedly priced at about half the token price of the GPT-5.6 Sol and Luna models (≈50% reduction reported).
Positioned for high-volume, well-defined, repeatable tasks — examples given include summarizing documents, extracting information, and answering short questions. Coverage describes Luna as making focused, repeatable tasks practical at high volume where small differences in latency and cost matter.
Reportedly used to run ChatGPT Voice: OpenAI's voice feature runs on GPT-6 Astra, Sol, and Luna and can access plugins like email, calendar, and Slack (i.e., Luna is used for voice interactions in ChatGPT's feature set).
BENCHMARKS · Reported benchmark/performance change versus predecessorDEVELOPER CLAIM
One report states Luna 'improves on its predecessor by 5.4 percentage points while costing 58 percent less' on the evaluations referenced by that coverage; the excerpt does not name the specific benchmark.
CAPABILITIES · Used as foundation for Decisions APIDEVELOPER CLAIM
Reportedly the Decisions API is built on GPT-6 Luna for fast, single decisions and classification tasks (i.e., Luna is used as the model for that API).
LIMITATIONS · Performance note / limitation reported by coverageDEVELOPER CLAIM
Some coverage characterizes Sol and Luna as largely matching their predecessors' performance while delivering significant price reductions (phrases used include 'barely move the needle on performance'), indicating that the primary change in these releases was cost efficiency rather than large capability gains.
WHAT CHANGED
Stored passport versions, without reconstructed history.
Passport updated13 facts
AVAILABILITY · Availability on Amazon Bedrock− Reportedly generally available on Amazon Bedrock.
RELEASE · Release / announcement dateIntroduced alongside GPT-6 Sol as part of the GPT-6 family on 2026-09-22.→Announced/launched on September 22, 2026.
OTHER · API identifierProvided in the API under the name gpt-6-luna.→Provided in the API under the name gpt-6-luna.
AVAILABILITY · Availability in ChatGPT clientsAt launch, Luna is reported to be available in the ChatGPT desktop app and to Free and Go users; broader ChatGPT availability was described as rolling out gradually.→At launch, Luna is reported to be available in the ChatGPT desktop app and to Free and Go users; broader ChatGPT availability was described as rolling out gradually.
CAPABILITIES · Used as foundation for Decisions API+ Reportedly the Decisions API is built on GPT-6 Luna for fast, single decisions and classification tasks (i.e., Luna is used as the model for that API).
AVAILABILITY · Availability and distribution channels+ Reportedly available on Amazon Bedrock (generally available). Also offered in ChatGPT Work and Codex for paid accounts; Luna is available in the ChatGPT desktop app and for Free and Go users; offered via the API as gpt-6-luna, with rollout in the ChatGPT app described as gradual.
OTHER · Role in high-volume workloadsPositioned to make focused, repeatable tasks practical at high volume, where small differences in latency and cost multiply across requests.→Positioned to make focused, repeatable tasks practical at high volume, where small differences in latency and cost multiply across requests.
CAPABILITIES · Intended use-cases / capabilities+ Positioned for high-volume, well-defined, repeatable tasks — examples given include summarizing documents, extracting information, and answering short questions. Coverage describes Luna as making focused, repeatable tasks practical at high volume where small differences in latency and cost matter.
PRICING · Published token pricing (reported)− Reported pricing: $0.10 per million input tokens and $0.50 per million output tokens for GPT-6 Luna.
LIMITATIONS · Performance note / limitation reported by coverage+ Some coverage characterizes Sol and Luna as largely matching their predecessors' performance while delivering significant price reductions (phrases used include 'barely move the needle on performance'), indicating that the primary change in these releases was cost efficiency rather than large capability gains.
PRICING · Price change versus previous generationReportedly priced at about half the token price of the GPT-5.6 Sol and Luna models (≈50% reduction reported).→Reportedly priced at about half the token price of the GPT-5.6 Sol and Luna models (≈50% reduction reported).
BENCHMARKS · Reported benchmark/performance change versus predecessor+ One report states Luna 'improves on its predecessor by 5.4 percentage points while costing 58 percent less' on the evaluations referenced by that coverage; the excerpt does not name the specific benchmark.
OTHER · Primary intended tasks (examples)Described as suited to clerical, high-volume tasks with clear goals — e.g., summarizing documents, extracting information, and answering quick questions.→Described as suited to clerical, high-volume tasks with clear goals — e.g., summarizing documents, extracting information, and answering quick questions.
PRICING · Pricing and cost relative to predecessor+ Announced at roughly half the token price of the GPT-5.6 Sol/Luna predecessors. Reporting gives Luna's list prices as $0.10 per million input tokens and $0.50 per million output tokens. OpenAI attributes lower API prices to caching and inference improvements; articles also report a broader 50% price cut vs the 5.6 series and additional prompt-caching discounts for GPT-6.
MODALITIES · Supported modalities / runtime usage+ Reportedly used to run ChatGPT Voice: OpenAI's voice feature runs on GPT-6 Astra, Sol, and Luna and can access plugins like email, calendar, and Slack (i.e., Luna is used for voice interactions in ChatGPT's feature set).
Passport created8 facts
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