GPT-6 Luna

SyncDev model directory · Profile updated Oct 13, 2026

Compare with another model

GPT-6 Luna is OpenAI's lower-cost GPT-6 option for text and image tasks that return text.

Key specifications

Specification score
75.8
Context window
1.05M
Max output
128K
Input / 1M tokens
$0.10
Output / 1M tokens
$0.50
License
Provider terms

The specification score summarizes recorded features and limits. It is not a benchmark result.

Inputs and outputs

Recorded modality support shows what this model can accept and produce. An undocumented modality is shown as unknown rather than assumed to be unsupported.

Accepts

  • Text input
  • Image input

Produces

  • Text output

Capabilities

ReasoningFunction callingVisionStreamingJSON mode

What is GPT-6 Luna?

GPT-6 Luna is OpenAI's lower-cost GPT-6 option for text and image tasks that return text.

Where it fits

Luna is worth testing for frequent, bounded work such as classifying a request, extracting fields or drafting a short response. Build a test set with ambiguous inputs and cases where the correct answer is to leave a field unknown. The important measure is the share of outputs your application can accept without repair.

API integration

The Responses API provides tool workflows. Chat Completions function calling requires reasoning_effort set to none. Reasoning effort affects both response time and the amount of generated work, so keep it fixed when measuring an alternative.

Limits and pricing

The documented context allowance is 1,050,000 tokens, with up to 128,000 output tokens. Standard rates for prompts up to 272,000 input tokens are $0.1 input and $0.5 output per million tokens. Longer prompts use higher rates across the request; cache writes, processing tiers and regional options can also change the bill.

A practical evaluation

Keep representative tasks, expected outcomes and failure cases together. Measure total cost to an accepted result, time to completion and the work a person must redo. Compare a smaller route before assigning every request to the same model. Explore OpenAI models or compare two candidates.

How to evaluate GPT-6 Luna

Compare the model on the work you need to complete.

Tasks and inputs

GPT-6 Luna is listed for Image-text-to-text, Text generation. It accepts text, image and produces text. Use the publisher’s input format and preprocessing for your chosen deployment.

Capacity and cost

Documented limits: 1.05M context and 128K maximum output. The listed route charges $0.10 input and $0.50 output per million tokens. Measure a completed task using the prompts, documents and tools your application will use. Include reasoning and retries in the result.

Choosing a deployment

Use the model identifier and account requirements for the selected API route. Confirm its request limits and output format with one complete task before connecting a larger workflow.

Frequently asked questions

Check the publisher documentation, exact model or checkpoint ID, runtime compatibility and current access terms. Test representative inputs and record failures, latency and total cost before changing a production route.

These records share a directory category. Check the source card, output type and deployment requirements before treating a model as a replacement.

Anthropic

Claude Haiku 5.5

Claude’s small model for high-volume extraction, classification and routing, with adaptive thinking and a 1M-token context window.

1M contextCompare

Mistral AI

Mistral Large 4

Mistral Large 4 is an open-weight multimodal model released in public preview on the publisher’s announced release, for general reasoning, coding and agent applications.

1M context

OpenAI

GPT-6.1 Sol

GPT-6.1 Sol is OpenAI's updated Sol model for coding and professional tasks. It accepts text and images and returns text.

1.05M contextCompare

inclusionAI

Ling 3.1 Flash

Ling 3.1 Flash is inclusionAI’s hybrid reasoning model for coding and tool agents, available through a hosted AI Gateway route.

262.14K context

Anthropic

Claude Sonnet 5.5

Claude Sonnet 5.5 is an Anthropic language model that accepts text and images and returns text.

1M context

MiniMax

MiniMax M3.1 Flash Preview

MiniMax M3.1 Flash Preview is a multimodal reasoning model for code and agent workflows, accessed through eligible MiniMax plans and tools.

1M context