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GPT-6 Luna vs SAM 3

Compare GPT-6 Luna and SAM 3 side-by-side. See how these vision models stack up in Object Detection and Segmentation.

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OpenAIGPT-6 Luna
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MetaSAM 3
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Models in this comparison

Meta

GPT-6 Luna vs SAM 3 Comparison Table

Evals updated October 8, 2026Pricing updated October 9, 2026

PropertyGPT-6 LunaSAM 3
OrganizationOpenAIMeta
Categoryclosedopen
Modalitymultimodalmultimodal
Release DateSep 2026Nov 2025
Context Window1.1M—
ParametersUnknownUnknown
LicenseProprietaryCustom
Pricing per 1M tokens
Input $/1M$0.100No published price
Output $/1M$0.500No published price
Vision Tasks
Object DetectionDemoDemo
Promptable Concept SegmentationDemoDemo
CaptioningDemoNot listed
Chart Question AnsweringSupportedNot listed
ClassificationDemoNot listed
Document Question AnsweringSupportedNot listed
Image TaggingSupportedNot listed
Instance SegmentationNot listedSupported
Multi-Label ClassificationSupportedNot listed
OCRDemoNot listed
Open Vocabulary Object DetectionNot listedSupported
Video Object TrackingNot listedSupported
Vision LanguageSupportedNot listed
Visual Question AnsweringDemoNot listed
Zero Shot SegmentationNot listedSupported
Model Features
Foundation VisionSupportedSupported
Multimodal VisionSupportedSupported
LLMs with Vision CapabilitiesSupportedNot listed
Zero-shot DetectionNot listedSupported
Vision Evalsground-truth scores across 5 vision tasks, pooled at low effort
Overall
69.7%
Not evaluated
Avg cost / sample$0.0004–
Avg speed / sample10.21s–
By task
Object Detection (low)
65.5%
±0.4, Mean of 3 runs, range 65.2 to 66.0
$0.0006
–
Object Detection (high)
68.0%
±0.7, Mean of 3 runs, range 67.3 to 68.6
$0.0014
–
Counting (low)
71.6%
±0.0, Mean of 3 runs, range 71.6 to 71.6
$0.0002
–
Counting (high)
72.1%
±0.7, Mean of 3 runs, range 71.6 to 73.0
$0.0004
–
Identification (low)
87.5%
±3.1, Mean of 3 runs, range 84.4 to 90.6
$0.0002
–
Identification (high)
87.5%
±3.1, Mean of 3 runs, range 84.4 to 90.6
$0.0002
–
OCR (low)
59.8%
$0.0004
–
by category
Single value
41.7%
Transcription
80.0%
Structured JSON
78.2%
Text localization
47.4%
OCR (high)
62.5%
$0.0013
–
by category
Single value
44.4%
Transcription
84.0%
Structured JSON
81.0%
Text localization
50.0%
Reasoning (low)
64.2%
±3.0, Mean of 3 runs, range 60.3 to 66.2
$0.0003
–
Reasoning (high)
71.1%
±2.3, Mean of 3 runs, range 68.2 to 72.8
$0.0004
–

GPT-6 Luna vs SAM 3: Overview

GPT-6 Luna

GPT-6 Luna is the fast, cost-efficient tier of OpenAI's GPT-6 model family, sitting below GPT-6 Sol and the larger GPT-6 Astra model that opened the generation. It is a proprietary multimodal transformer that accepts text and image input and returns text, and it exposes an adjustable reasoning effort setting so the same model can run in a low-latency mode or spend additional inference compute on harder problems. OpenAI positions it for high-volume and latency-sensitive workloads such as conversational assistants, classification, and lightweight agentic pipelines, while noting that at higher reasoning effort it handles software engineering and computer-use tasks that previously required a Sol-tier model.

The model supports a context window of roughly 1,050,000 input tokens with a maximum output of 128,000 tokens, which allows long documents, extended agent traces, and large code repositories to be processed in a single request. OpenAI describes the GPT-6 generation as improving factual reliability and adopting a more concise communication style relative to the GPT-5.6 series, and attributes the efficiency of the Sol and Luna tiers to gains in caching and inference rather than to reduced capability. Architecture details, parameter counts, and training data are not published.

SAM 3

Released on November 19th, 2025, Segment Anything 3 (SAM 3) is a zero-shot image segmentation model that “detects, segments, and tracks objects in images and videos based on concept prompts.” This model was developed by Meta as the third model in the Segment Anything series.

Unlike its previous SAM models (Segment Anything and Segment Anything 2), you can provide SAM 3 with the prompt “shipping container” and it will generate precise segmentation masks for all shipping containers in an image. SAM 3 generates segmentation masks that correspond to the location of the objects found with a text prompt.

Frequently Asked Questions

SAM 3 has not yet been evaluated on Roboflow's current Vision Evals, so this comparison shows specs, licensing, and pricing rather than benchmark scores.

GPT-6 Luna is released under Proprietary, while SAM 3 uses Custom. Licensing often matters more than raw accuracy for commercial deployments, so check the terms against how you plan to ship.

Yes. The comparison demo on this page runs both models on the same image side by side for object detection and segmentation in the free Roboflow Playground. You can try it instantly, and a free account unlocks unlimited runs.