GPT-6 Guide: Astra, Sol, Luna, Prices & How to Use It
Understand GPT-6, compare Astra, GPT-6.1 Sol and Luna, check API prices, and find the right official ChatGPT, Work or developer entry point.
Last updated: 2026-10-25
GPT-6 is OpenAI’s model family. For demanding reasoning, evaluate Astra; for complex work where cost matters, consider GPT-6.1 Sol; for focused, repeatable tasks, consider Luna. If you simply want to chat, start at official ChatGPT. This independent guide explains the choices; it does not provide GPT-6 access.
What is GPT-6, and is it available?
GPT-6 is available, rather than an upcoming release rumor. OpenAI’s current API model catalog lists GPT-6 Astra, GPT-6.1 Sol and GPT-6 Luna. GPT-6.1 Sol and the earlier GPT-6 Sol are different versions: check the exact name when comparing a review, price or model selector.
ChatGPT’s everyday Chat experience is a separate product surface. OpenAI’s October 7 announcement introduced GPT-6 with Intelligent UI: answers can include visuals, controls and interactive explanations. It described a rollout to paid plans, followed by Free and Go, with access subject to rollout and workspace settings. That announcement did not change the models used by Work or Codex.
Astra vs Sol vs Luna: which should you choose?
| Model | Consider it for | Check before adopting it |
|---|---|---|
| GPT-6 Astra | Ambiguous research, difficult coding and demanding workflows | Whether better results reduce corrections enough to justify the cost |
| GPT-6.1 Sol | Complex coding, research and documents with a tighter budget | Missed constraints, retries and the final result you can accept |
| GPT-6 Luna | Extraction, classification and focused, repeated tasks | Accuracy on exceptions and when to escalate a failed task |
These are starting recommendations, not a benchmark ranking. The official selection guide recommends testing with the same inputs and keeping the lightest model and effort that meets your quality bar. A higher version number alone does not make Sol the strongest model in the family.
For example, label a batch of short support messages with Luna, evaluate Sol for a code change with clear acceptance checks, and compare Astra when an unfamiliar system or conflicting evidence repeatedly trips up the other model. Define success before comparing cost.
GPT-6 API prices
On a small screen, scroll the price table sideways.
| Exact API model ID | Uncached input | Cached input | Output |
|---|---|---|---|
| gpt-6-astra | $10.00 | $1.00 | $50.00 |
| gpt-6.1-sol | $2.00 | $0.10 | $10.00 |
| gpt-6-luna | $0.10 | $0.01 | $0.50 |
Source: OpenAI API pricing. These are usage rates, not monthly ChatGPT subscription prices. Cache writes, tools, retries, regional processing and other service tiers can add or change charges.
For 20,000 uncached input tokens + 5,000 billable output tokens, one Standard request costs $0.45 on Astra, $0.09 on Sol, or $0.0045 on Luna. This arithmetic excludes the extras above. More attempts or a longer answer can change the cost per successful task.
The individual Astra, Sol and Luna model pages specify a long-context threshold: above 272,000 input tokens, 2× input/cache rates and 1.5× output rates apply to the entire request. Their listed context window is 1,050,000 tokens and maximum output is 128,000 tokens; these limits do not guarantee every request will fit or every product offers that context.
Need to compare the two larger models in detail? See our Sol vs Astra comparison, published benchmark evidence and cost calculator.
How to use GPT-6
1. For everyday chat
Open chatgpt.com and use the account and controls available to you. The October announcement described the everyday Chat experience as using a tuned Sol model for paid plans and Luna for Free/Go. That does not mean every account can manually select every named model. Follow the controls and limits shown in your account.
Try a task with a clear outcome: “Compare these three options against my budget and constraints. Cite the facts you use and explain which assumptions could change the choice.” See our beginner’s guide for the first conversation.
2. For Work or Codex
In a supported client, choose an available model and reasoning effort using the model control. Higher effort can take longer and consume more usage. Availability depends on your product, plan, account and client. The official models documentation describes the controls; product pricing and usage explains allowances. API token prices cannot predict a fixed number of subscription tasks.
3. For an application using the API
Follow the official GPT-6 API guide, use an exact model ID from the table, and set up a Responses API request. Keep API credentials on your server. Astra and GPT-6.1 Sol support low through max reasoning effort but not none; Luna also supports none. Check tool and parameter compatibility before changing an existing integration.
Is GPT-6 free? Do I need to download it?
Free ChatGPT access and a paid API are different offers. Do not assume a Free account includes a particular GPT-6 model: the October 7 announcement included Free/Go in its rollout plan, while the current Help Center availability guide still describes older default models for those plans. Check the model shown in your account. Free access does not imply unlimited Astra use or free API credit.
For browser use, start on the official ChatGPT website. A third-party “GPT-6 download” or a registration on this guide does not grant OpenAI access. This website’s prompt builder only organizes your task brief locally; you paste the result into your chosen assistant.
What about benchmarks, speed and competing models?
We have not run an independent GPT-6 benchmark. A score from one coding test, a game or a different reasoning setting cannot establish the best model for every task. Our detailed comparison separates evaluator measurements, vendor evidence and practical recommendations.
When comparing GPT-6 with another provider, record the exact versions, tools, effort, total elapsed time, all attempts’ charges and human correction time. Use the same task and acceptance checks. Compare total charges divided by accepted results, and report failure when no result passes. Token throughput alone does not measure time to a usable deliverable.
Sources and updates
Model specifications and prices were checked on October 25, 2026. Official documentation and your account’s current access take precedence as products change. Sources are linked beside the claims they support. For a clearer task brief, continue with our prompt-writing guide; for access issues, use troubleshooting. Corrections: jimmysenior360@gmail.com.