For the complete documentation index, see llms.txt. Markdown versions of documentation pages are available by appending .md to the page URL.
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Model selection

Find the right model for your use case

Meet the models

Astra

State-of-the-art intelligence

Ambiguous problems, deep analysis, and ambitious deliverables.

Sol

Great everyday driver

Writing, coding, and work that needs judgment.

Luna

Smart and efficient

Scoped tasks, triage, and frequent automations

Availability, tools, reasoning settings, and usage limits differ by product and model version. Check the models available in ChatGPT or the API model catalog.

Find the right model for your workflow

Choose your work and task and get a recommendation.

What type of work are you doing?

How to think about models and reasoning effort

Luna is the most cost-efficient model, while Astra is our state-of-the-art, most powerful model. If cost and latency aren’t a concern, you can default to Astra. To reduce costs or latency, use the guidance below to choose a model and reasoning effort for your needs.

Luna is our most efficient model, while Astra is our state-of-the-art, most powerful model. If you don’t need to think about usage or how long it takes to complete a task, you can default to Astra. To optimize usage, use the guidance below to choose a model and reasoning effort for your needs.

Model and reasoning effort

  1. Luna · Low

    Fine-grained edits, well-scoped problem-solving, and simple data extraction.

  2. Luna · Medium

    Creating from clear briefs and making coordinated updates to existing work.

  3. Luna · Extra high

    Finding current context across multiple apps, prioritizing work, and solving problems with clear constraints.

  4. Sol · Low

    Focused writing and editing, fact-checking, and straightforward work in apps.

  5. Sol · Medium

    Everyday coding, research, and workflows that need judgment and completeness.

  6. Sol · Extra high

    Deeper analysis, thorough verification, and careful review of documents, data, and code.

  7. Astra · Low

    Concise writing and content adaptation that preserve facts and nuance.

  8. Astra · Medium

    Ambitious projects that need broad context, reliable interactions, and complete results.

  9. Astra · Extra high

    Demanding analysis and complex deliverables with exacting requirements.

Model strengths
3D and design Software Data and analysis Documents and slides Computer use Research and planning

Experiment

Treat the guidance on this page as a starting point. The best way to find the right model for your workflow is to experiment with different models and reasoning settings to see what works.

Start by considering:

  • How often does your workflow run? A frequent automation makes usage and cost add up faster than an occasional project.
  • How quickly do you need the result? A task you’re waiting on may need a faster setting than one that runs overnight.
  • How will you use the output? A draft for your review may need less polish than something you’ll share externally.
  • How important is the quality of the result? Depending on your use case or industry, you might want to use a stronger model to put an emphasis on quality.

If you can, experiment using the same inputs to compare results and keep the lightest setting that meets your quality bar.