AI Model Profile
GPT-5.6 Luna
GPT-5.6 Luna is the cost-optimised tier of the GPT-5.6 family, retaining the full 1,050,000-token context window and reasoning-token support.
Before you buy
Best for: Cost-sensitive workloads that still need a very large context window and reasoning support.
Price: USD API: US$0.20 input / US$1.20 output per 1M tokens
Included: GPT-5.6 Luna is the cost-optimised tier of the GPT-5.6 family, retaining the full 1,050,000-token context window and reasoning-token support.
Main limits: Reasoning tier is high rather than highest. Output is text only. Standard list rates; cache writes, tools, long-context premiums, regional processing and other service tiers can change the bill.
What Kingy showed: Related coverage: Best AI Model API in 2026: A Use-Case and Routing Guide. This review does not treat that article as a new test of this exact model, plan or current release.
Buying details checked 2026-10-23 with region and currency stated above. Historical demonstrations and the broader fact ledger keep their own dates.
Check official plans · See the demonstration and disclosure · Compare these workflows
- Family
- GPT-5
- Release date
- Unknown
- Status
- Current
- Context window
- 1,050,000 tokens
- Output limit
- 128,000 tokens
- API
- yes
- Open weights
- no
- Local/self-hosted
- no
- Pricing
- OpenAI API pricing checked September 21, 2026: Standard requests with up to 272K input tokens cost $0.20 per million input tokens, $0.02 cached input and $1.20 output. Batch input/cached input/output: $0.10/$0.01/$0.60. Longer prompts, cache writes, processing tier and eligible regional processing affect the charge.
- Evidence state
- Recheck due
Benchmark Caveat
Benchmarks and provider capability notes are directional, not universal rankings. Results can shift with prompts, tool use, latency targets, pricing tier, safety filters, context length, and the workload mix a real team runs.
See the linked official model, docs, model-card, or pricing source for provider-published capability notes.
Best for
Cost-sensitive workloads that still need a very large context window and reasoning support.
Skip if
Skip if the workload needs the highest reasoning tier available in the family.
Strengths
OpenAI lists Luna with the same 1,050,000-token context window and 128,000 max output tokens as Sol and Terra, at the lowest price in the family, with a high reasoning tier, reasoning-token support, text and image input, and supported function calling.
Weaknesses
Reasoning tier is high rather than highest. Output is text only.
Agent suitability
Useful for agent workflows when the provider supports tool use, long context, structured outputs, or workflow-specific APIs.
Kingy AI take
Use this as a source-backed shortlist candidate, not a universal ranking. Re-check official provider docs and run a task-specific trial before production adoption.
Kingy AI Product Facts
GPT-5.6 Luna
Current statusUnknown
- Company
- Not yet reviewed
- Primary job
- Not yet reviewed
- Audience
- Not yet reviewed
- Evidence
- Source-backed; coverage expanding
- Latest source check
- October 29, 2026
See all tracked product factsPricing, platforms, dependencies, data claims, regions, and timeline
Sources and checks
- Coverage
- 4 of 88 tracked fields currently verified
- Sources
- 1
Source-check dates apply to the tracked facts. Editorial updates elsewhere on this page may have a different date.
Plans and pricing units
Not yet structured in this Kingy record.
Where it runs
- Availability
- Not yet reviewed
Stack and integrations
- Model / provider dependencies
- Not yet reviewed
- Integrations
- Not yet reviewed
Data and regions
- Vendor data-use claim
- Not yet reviewed
- Vendor retention claim
- Not yet reviewed
- Regions
- Not yet reviewed
Launch and latest material update
- Launch
- Not yet reviewed
- Latest material update
- Not yet reviewed
Full Model Notes
Who should consider it
Cost-sensitive workloads that still need a very large context window and reasoning support. GPT-5.6 Luna is the cost-optimised tier of the GPT-5.6 family, retaining the full 1,050,000-token context window and reasoning-token support.
Plan, price and billing scope
USD API: US$0.20 input / US$1.20 output per 1M tokens. GPT-5.6 Luna is the cost-optimised tier of the GPT-5.6 family, retaining the full 1,050,000-token context window and reasoning-token support. Prices use the currency and billing term stated here. Where a numeric rate, region or current entitlement could not be verified, it remains explicit; no checkout was completed.
Limits that affect the decision
Reasoning tier is high rather than highest. Output is text only. Standard list rates; cache writes, tools, long-context premiums, regional processing and other service tiers can change the bill.
What the existing evidence shows
Related coverage: Best AI Model API in 2026: A Use-Case and Routing Guide. This review does not treat that article as a new test of this exact model, plan or current release. Related workflow reading; not a demonstration of this exact product. Read the related article.
Sources and buying-review date
Buying review completed October 23, 2026. This is a source-based buying assessment. No paid product test, new generation, checkout or performance benchmark was performed. Vendor descriptions and historical examples remain distinct from independently measured results. The date does not renew the broader canonical fact ledger.
- Official source: developers.openai.com
- Official source: developers.openai.com
- Official source: chatgpt.com
- Official source: developers.openai.com
- Related Kingy coverage
Check the official offer · Compare related options
Earlier profile, sources and dates
This older record retains its original scope. Current buying qualifications above take precedence where terms have changed.
The Kingy Brief
Get The Kingy Brief.
AI changes, original tests and one practical thing to try. Fridays at 09:00 Vancouver time.
Free · Double opt-in · Unsubscribe anytime
Sign up for The Kingy Brief on Beehiiv.
Signup help and newsletter schedule
Signup form provided by Beehiiv. After submitting, check your inbox for "Confirm your subscription to The Kingy Brief" and open its confirmation link. Check Spam or Promotions if you cannot find it.
Fridays at 09:00 Vancouver time: source-checked AI changes, original tests and one practical thing to try. We skip a week when there is not enough verified material. Free. Unsubscribe anytime.
Coding notes
Use official docs and live evals before selecting this model for production coding workflows.
Reasoning notes
Provider capability notes are useful but should be validated on representative prompts and tools.
Creative notes
Use a small creative test set before standardizing outputs for brand, media, or customer-facing work.
Research notes
Track release notes and model lifecycle notices because availability and aliases can change.
API pricing notes
Pricing rechecked September 21, 2026. Amounts use the dollar notation displayed in OpenAI’s official API pricing table, per million tokens. For up to 272K input tokens, rates in input / cached input / cache write / output order are: Standard $0.20 / $0.02 / $0.25 / $1.20; Batch and Flex $0.10 / $0.01 / $0.125 / $0.60; Fast $0.40 / $0.04 / $0.50 / $2.40. Above 272K input tokens, the full request uses 2× these input, cached-input and cache-write rates and 1.5× the output rate. Fast replaces Priority processing. Eligible regional-processing endpoints add 10%; tool charges may be additional. These are API token rates, not ChatGPT or Codex subscription allowances. No paid API call or billing test was performed.
License notes
Commercial/API terms apply unless the linked official source states otherwise.
Hardware requirements
Cloud/API model; local hardware requirements are not published as a self-hosted path.
Official Model Links
Kingy coverage
Kingy AI articles that cover GPT-5.6 Luna, newest first.
Model Intelligence Research Map
Use these internal paths to move from this model profile into provider pages, static comparison pages, related Kingy records, and the broader AI launch graph. These are research paths, not rankings.