OpenAI / generation

GPT-5.6 family

Sol, Terra and Luna are distinct named model rows. Pro reasoning mode and reasoning effort are separate controls; a marketplace suffix is not automatically a direct API model ID.

Family research reviewed · Official source notes below

Standard models
6
Independently rated
3 / 6
Known token rates
6 / 6
Global balanced frontier
0

Before you choose

Model, mode and effort

OpenAI documents Sol as the successor to the earlier unsuffixed tier. The direct API treats Pro mode and reasoning effort as separate controls. Confirm the endpoint syntax rather than copying a marketplace slug.

Compare exact catalogue rows

USD per 1M tokens. In / out are listed base rates; expand billing conditions before planning a request. LMArena scores measure the general preference board, not success on your engineering task. Unknown stays unknown.

Pro-labelled catalogue rows

ModelLMArenaInput / output $/MContext / max outputCapabilities & conditions
GPT-5.6 Luna Proopenai/gpt-5.6-luna-proUnrated$0.200 / $1.20Context tiers apply
Billing details
Cached input
$0.020
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $0.400 in / $1.80 out; cached $0.040.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesWeights unknownReleased 2026-07-09
GPT-5.6 Terra Proopenai/gpt-5.6-terra-proUnrated$2.00 / $12.00Context tiers apply
Billing details
Cached input
$0.200
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $4.00 in / $18.00 out; cached $0.400.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesWeights unknownReleased 2026-07-09
GPT-5.6 Sol Proopenai/gpt-5.6-sol-proUnrated$2.00 / $10.00Context tiers apply
Billing details
Cached input
$0.200
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $4.00 in / $15.00 out; cached $0.400.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesWeights unknownReleased 2026-07-09

Other generation members

ModelLMArenaInput / output $/MContext / max outputCapabilities & conditions
GPT-5.6 Lunaopenai/gpt-5.6-luna1429.9±4.8 interval half-widthEffort: xhigh$0.200 / $1.20Context tiers apply
Billing details
Cached input
$0.020
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $0.400 in / $1.80 out; cached $0.040.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesClosed weightsReleased 2026-07-09
GPT-5.6 Terraopenai/gpt-5.6-terra1446.2±4.8 interval half-widthEffort: xhigh$2.00 / $12.00Context tiers apply
Billing details
Cached input
$0.200
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $4.00 in / $18.00 out; cached $0.400.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesClosed weightsReleased 2026-07-09
GPT-5.6 Solopenai/gpt-5.6-sol1455.1±4.9 interval half-widthEffort: xhigh$2.00 / $10.00Context tiers apply
Billing details
Cached input
$0.200
Separate reasoning
Not separately listed
  • Above 272,000 input tokens: $4.00 in / $15.00 out; cached $0.400.

Tool, media, cache-write and service-tier charges may add dimensions. Read the full model evidence.

1,050,000Output 128,000file · image · textTools yes · reasoning yesClosed weightsReleased 2026-07-09

Free and batch variants

These rows have different access or processing conditions. They are excluded from the standard-row counts above. A variant without a standard base remains a separately named variant.

Sources and scope

  • GPT-5.6 Sol ↗

    Exact named models on the vendor platform; not a promise about every reseller

    Checked 2026-09-22 · official document opened and inspected
  • OpenAI reasoning guide ↗

    Exact named models on the vendor platform; not a promise about every reseller

    Checked 2026-09-22 · web opened; full official Markdown fetched with HTTP 200 and inspected

Source review does not refresh a price or transplant a benchmark score. Read the method and correction policy.

Questions this page answers

Are the GPT-5.6 family models interchangeable?

No. These are exact catalogue rows with separate capability, pricing and rating evidence. Compare the checkpoint, serving endpoint, reasoning settings and required input types. A family name does not establish equivalent behaviour.

How many OpenAI rows are compared here?

6 standard rows, of which 3 have an accepted LMArena general score and 6 have known input and output token rates. 6 related free or batch variants are listed separately.

What do the prices and frontier counts mean?

Prices below are listed US dollars per million input or output tokens, before request-specific context tiers and other billing dimensions. The frontier count comes from the global balanced view. Neither a family price range nor a benchmark difference proves your task will be cheaper or more successful.

How current are the official notes?

The linked family research was reviewed 2026-09-22. That date is separate from each accepted catalogue observation and each vendor’s effective date. An official note applies to its named platform, not automatically to every reseller.

Evidence & Ask