GPT-6 Luna Pro vs Grok 4.20

Price, context window & benchmark comparison

O

GPT-6 Luna Pro

OpenAI
$0.10 / $0.50
Input / Output · per 1M tokens
VS
X

Grok 4.20

xAI
$1.25 / $2.50
Input / Output · per 1M tokens
Compare different models
O
X
Verdict: GPT-6 Luna Pro is 7.8× cheaper than Grok 4.20 on a typical 3:1 input/output mix. Grok 4.20 has the larger context window (2M vs 1.1M).
GPT-6 Luna ProGrok 4.20
Input price / 1M$0.10$1.25
Output price / 1M$0.50$2.50
Blended price (3:1)$0.20$1.56
Cached input / 1M$0.01$0.20
Context window1.1M2M
Max output128K1.8M
Intelligence index——
Coding index——
Providers6—
Best provider uptime (30m)100.0%—
Vision inputYesYes
ReasoningYesYes
Tool callingYesYes
Released2026-09-222026-03-31
Retirement——

Cost calculator

FAQ

Which is cheaper, GPT-6 Luna Pro or Grok 4.20?

GPT-6 Luna Pro is 7.8× cheaper than Grok 4.20 on a typical 3:1 input/output mix.

GPT-6 Luna Pro vs Grok 4.20: which has a bigger context window?

GPT-6 Luna Pro: 1,050,000 tokens. Grok 4.20: 2,000,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GPT-6 Luna Pro ≈ $450.00, Grok 4.20 ≈ $3,750.

More comparisons

GPT-6 Luna Pro vs GLM 5.3 PrimeGPT-6 Luna Pro vs Qwen3.8 Max PrimeGPT-6 Luna Pro vs Command A+GPT-6 Luna Pro vs GPT-6 LunaGPT-6 Luna Pro vs GPT-6 Sol ProGPT-6 Luna Pro vs GPT-6 SolGPT-6 Luna Pro vs Claude Opus 5.5GPT-6 Luna Pro vs MiMo-V2.6-Pro-UltraSpeedGPT-6 Luna Pro vs MiMo-V2.6-FlashGPT-6 Luna Pro vs Grok 4.7GPT-6 Luna Pro vs Qwen3.8 Omni FlashGPT-6 Luna Pro vs GLM 5.3 FlashXGPT-6 Luna Pro vs DeepSeek V4.1 FlashGPT-6 Luna Pro vs GPT-6 AstraGPT-6 Luna Pro vs GPT-6 Astra ProGPT-6 Luna Pro vs Qwen3.8 Max (0902)Grok 4.20 vs GLM 5.3 PrimeGrok 4.20 vs Qwen3.8 Max PrimeGrok 4.20 vs Command A+Grok 4.20 vs GPT-6 LunaGrok 4.20 vs GPT-6 Sol ProGrok 4.20 vs GPT-6 SolGrok 4.20 vs Claude Opus 5.5Grok 4.20 vs MiMo-V2.6-Pro-UltraSpeed