Model Comparison

GPT-5.6 Luna vs Grok-1.5VWhich is better in 2026?

Comparing GPT-5.6 Luna and Grok-1.5V across benchmarks, pricing, and capabilities.

Verdict: GPT-5.6 Luna vs Grok-1.5V — which is better?

GPT-5.6 Luna (by OpenAI) and Grok-1.5V (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Choose GPT-5.6 Luna if…

  • you want the most recent training data — it shipped Jul 2026

Choose Grok-1.5V if…

  • you are already invested in the xAI ecosystem

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.6 Luna and Grok-1.5Vdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-5.6 Luna specifies input context (1,050,000 tokens). Only GPT-5.6 Luna specifies output context (128,000 tokens).

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
xAI
Grok-1.5V
Input- tokens
Output- tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.6 Luna and Grok-1.5V support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.6 Luna

Text
Images
Audio
Video

Grok-1.5V

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.6 Luna

Proprietary

Closed source

Grok-1.5V

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while Grok-1.5V was released on 2024-04-12.

GPT-5.6 Luna is 27 months newer than Grok-1.5V.

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

2.2yr newer
Grok-1.5V

Apr 12, 2024

2.3 years ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Grok-1.5V's cutoff date is not specified.

We can confirm GPT-5.6 Luna's training data extends to 2026-02-16, but cannot make a direct comparison without Grok-1.5V's cutoff date.

GPT-5.6 Luna

Feb 2026

Grok-1.5V

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
xAI

No standout differentiators in the data we have for this pair.

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.6 Luna and Grok-1.5V side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
Grok-1.5V
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Luna
xAI
Grok-1.5V

FAQ

Common questions about GPT-5.6 Luna vs Grok-1.5V.

Which is better, GPT-5.6 Luna or Grok-1.5V?

GPT-5.6 Luna (OpenAI) and Grok-1.5V (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5.6 Luna compare to Grok-1.5V in benchmarks?

GPT-5.6 Luna scores Connectors: 99.9%, HealthBench Consensus: 95.1%, GPQA: 92.3%, Search and Function-Calling: 89.7%, Capture-the-Flag Challenges (Internal): 85.2%. Grok-1.5V scores AI2D: 88.3%, DocVQA: 85.6%, TextVQA: 78.1%, ChartQA: 76.1%, RealWorldQA: 68.7%.

What are the context window sizes for GPT-5.6 Luna and Grok-1.5V?

GPT-5.6 Luna supports 1.1M tokens and Grok-1.5V supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes GPT-5.6 Luna and Grok-1.5V?

GPT-5.6 Luna is developed by OpenAI and Grok-1.5V is developed by xAI.

Related comparisons