Head-to-head · OpenAI vs xAI

GPT-6 Luna vs Grok 4.7

GL
GPT-6 Luna
OpenAI · API: $0.10 in / $0.50 out per M tokens
vs
G4
Grok 4.7
xAI · API: $2 to $4 in / $6 to $12 out per M tokens

Quick answer: GPT-6 Luna stands out for extremely cheap for bulk processing. Grok 4.7 stands out for large context window at a moderate price. Reviewed September 2026.

Overview

GPT-6 Luna: GPT-6 Luna, launched on 22 September 2026, is the small, low-cost member of the GPT-6 family at $0.10 and $0.50 per million tokens. It targets high-volume tasks where cost and speed matter most.

Grok 4.7: Grok 4.7 is xAI's latest flagship model for coding, agentic tasks and knowledge work. It has a 500,000-token context window, accepts text and image input, and supports adjustable reasoning levels.

At a glance

DimensionGPT-6 LunaGrok 4.7
VendorOpenAIxAI
Starting priceAPI: $0.10 in / $0.50 out per M tokensAPI: $2 to $4 in / $6 to $12 out per M tokens
Pricing model Paid Paid
Free tier No No
CategoryGenerative AIGenerative AI

Strengths and limits

GPT-6 Luna

  • Extremely cheap for bulk processing
  • Fast responses
  • Good fit for classification and extraction

Watch out for

  • Not suited to the hardest reasoning tasks
  • Newest release with limited track record
  • Quality varies by task, so test on your own data

Grok 4.7

  • Large context window at a moderate price
  • Strong on coding and agent tasks
  • Real-time knowledge through the xAI ecosystem

Watch out for

  • Smaller enterprise ecosystem than OpenAI, Anthropic or Google
  • Price steps up for prompts over 200,000 tokens
  • Fewer professional integrations

Key features

GPT-6 Luna

  • Very low per-token pricing
  • Built for high-volume and latency-sensitive work
  • Shares GPT-6 family technology
  • Available through the OpenAI API

Grok 4.7

  • 500,000-token context window
  • Text and image input
  • Flexible reasoning levels
  • Available through the xAI API

Pricing compared

GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Grok 4.7 is priced by usage rather than by seat: API: $2 to $4 in / $6 to $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Frequently asked questions

Which is better, GPT-6 Luna or Grok 4.7?

It depends on the work. GPT-6 Luna stands out for extremely cheap for bulk processing. Grok 4.7 stands out for large context window at a moderate price.

How do GPT-6 Luna and Grok 4.7 compare on price?

GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. Grok 4.7 is priced by usage rather than by seat: API: $2 to $4 in / $6 to $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.

Is there a free option between GPT-6 Luna and Grok 4.7?

Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.

Read the full reviews