GPT-5.6 Luna vs Grok 4.20
Rank, tier, score and price side by side, from our weekly rankings. Scores are editorial opinion based on public sources.
A
GPT-5.6 Luna
B
Grok 4.20
- ProviderOpenAIxAI
- Rank#39Higher rank#56
- TierAA
- Score81.4Higher score75.4
- Price$0.20 per 1M input tokens, $1.20 per 1M output tokensAPI $1.25 input / $2.50 output per 1M tokens (prompts under 200K; $2.50 / $5 above); also via Grok app subscriptions
- TaglineOpenAI's cost-optimized GPT-5.6 tier, repriced 80% lower in July 2026 for high-volume production workloads.A model with native tool use and real-time search integration that is designed for rapid learning and weekly improvement.
| Attribute | GPT-5.6 Luna | Grok 4.20 |
|---|---|---|
| Provider | OpenAI | xAI |
| Rank | #39Higher rank | #56 |
| Tier | A | A |
| Score | 81.4Higher score | 75.4 |
| Price | $0.20 per 1M input tokens, $1.20 per 1M output tokens | API $1.25 input / $2.50 output per 1M tokens (prompts under 200K; $2.50 / $5 above); also via Grok app subscriptions |
| Tagline | OpenAI's cost-optimized GPT-5.6 tier, repriced 80% lower in July 2026 for high-volume production workloads. | A model with native tool use and real-time search integration that is designed for rapid learning and weekly improvement. |