text model comparison
GPT-5.6 Luna vs Grok 4.6
GPT-5.6 Luna and Grok 4.6 are both current text models, from OpenAI and xAI. GPT-5.6 Luna is 90% cheaper per 1M input tokens than Grok 4.6, $0.20 vs $2. On Arena Text, GPT-5.6 Luna scores 1452 Elo and Grok 4.6 1454 Elo (Arena, measured October 8, 2026). GPT-5.6 Luna has the larger context window, 1,050,000 vs 500,000 tokens.
- Higher Arena Text
- Grok 4.61454 Elo against 1452 Elo
- Lower price per 1M input tokens
- GPT-5.6 Luna$0.20 against $2
- Longer context window
- GPT-5.6 Luna1.05M tokens against 500K tokens
- Newer release
- Grok 4.6Aug 2026 against Jul 2026
Data verified October 12, 2026 · Dataset 2026-10-28
Side by side
GPT-5.6 Luna and Grok 4.6, line by line
Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.
| Fact | GPT-5.6 Luna | Grok 4.6 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $0.20 (better) | $2 |
| Price per 1M output tokens | $1.20 (better) | $6 |
| Independent benchmarks | ||
| Arena Text | 1452 Elo (#34 of 49) | 1454 Elo (#33 of 49) (better) |
| GPQA Diamond | 91.6% (#20 of 40) | 94% (#9 of 40) (better) |
| FrontierMath Tiers 1-3 (v2) | 82.1% (#12 of 40) (better) | 66% (#24 of 40) |
| SimpleQA Verified | 41% (#27 of 36) | 49.3% (#20 of 36) (better) |
| Specs | ||
| Provider | OpenAI | xAI |
| Release date | July 9, 2026 | August 12, 2026 |
| Access | API only | API only |
| Context window | 1,050,000 tokens | 500,000 tokens |
| Max output | 128,000 tokens | Not reported |
| Input | text, image | text, image |
| Output | text | text |
Charts
Against every current text model
Where GPT-5.6 Luna and Grok 4.6 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
On Arena Text, GPT-5.6 Luna ranks #34 and Grok 4.6 #33 of 49 current models. Each bar is the share of current models it beats: on score, price and context.
Independent benchmarks
Arena Text
GPT-5.6 Luna:#34of 49
1,452 Elo · ahead of 31%
Grok 4.6:#33of 49
1,454 Elo · ahead of 33%
GPQA Diamond
GPT-5.6 Luna:#20of 40
91.6% · ahead of 51%
Grok 4.6:#9of 40
94% · ahead of 79%
FrontierMath Tiers 1-3 (v2)
GPT-5.6 Luna:#12of 40
82.1% · ahead of 72%
Grok 4.6:#24of 40
66% · ahead of 41%
SimpleQA Verified
GPT-5.6 Luna:#27of 36
41% · ahead of 23%
Grok 4.6:#20of 36
49.3% · ahead of 46%
Price and context
Price per 1M input tokens
GPT-5.6 Luna:#7of 51
$0.20 · cheaper than 84%
Grok 4.6:#28of 51
$2 · cheaper than 24%
Price per 1M output tokens
GPT-5.6 Luna:#10of 51
$1.20 · cheaper than 78%
Grok 4.6:#27of 51
$6 · cheaper than 42%
Context window
GPT-5.6 Luna:#1of 66
1.05M tokens · longer than 86%
Grok 4.6:#54of 66
500K tokens · longer than 15%
Quality against price
GPT-5.6 Luna scores 1,452 at $0.45; Grok 4.6 scores 1,454 at $3 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.
Quality against price: the data
| Model | Provider | Blended price per 1M tokens | Arena Text (Elo) |
|---|---|---|---|
| Gemini 4 Argon | $4 | 1,525 | |
| Claude Opus 5.5 | Anthropic | $8 | 1,507 |
| Claude Fable 5 | Anthropic | $20 | 1,504 |
| Claude Fable 5.1 | Anthropic | $20 | 1,501 |
| Gemini 3.8 Flash | $1.50 | 1,497 | |
| Muse Spark 1.3 | Meta | $2 | 1,494 |
| Claude Opus 5 | Anthropic | $10 | 1,490 |
| Kimi K3 | Moonshot Kimi | $6 | 1,488 |
| Gemini 3.7 Flash | $1.50 | 1,486 | |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| GPT-6.1 Sol | OpenAI | $4 | 1,484 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,483 |
| GPT-5.5 | OpenAI | $11 | 1,482 |
| Gemini 3.6 Flash | $3 | 1,482 | |
| Claude Opus 4.8 | Anthropic | $10 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| GLM-5.3 | Z.ai | $2.15 | 1,478 |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,476 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| GPT-6 Astra | OpenAI | $20 | 1,475 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,475 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,475 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,466 |
| Grok 4.5 | xAI | $3 | 1,466 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,465 |
| Claude Sonnet 5 | Anthropic | $4 | 1,461 |
| GPT-6 Sol | OpenAI | $4 | 1,456 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,455 | |
| Grok 4.6 | xAI | $3 | 1,454 |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,452 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,451 |
| GPT-6 Luna | OpenAI | $0.20 | 1,443 |
| Grok 4.7 | xAI | $3 | 1,443 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| Mistral Large 4 | Mistral AI | $2.06 | 1,429 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Solar Pro 4 | Upstage | $0.52 | 1,386 |
| GPT-4.1 mini | OpenAI | $0.70 | 1,383 |
| GPT-4.1 nano | OpenAI | $0.18 | 1,322 |
Cost
What each costs
Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.
The same work, priced
For 10M input and 2M output tokens, Grok 4.6 costs 7.3 times as much as GPT-5.6 Luna, at each provider's listed rates.
10M input and 2M output tokens
Grok 4.6 costs 7.3× as much
- GPT-5.6 Luna
- $4.40
- Grok 4.6
- $32
The same, with 9M of the input tokens cached
Grok 4.6 costs 6.7× as much
- GPT-5.6 Luna
- $2.78
- Grok 4.6
- $18.50
| Workload or rate | GPT-5.6 Luna | Grok 4.6 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $4.40 (better) | $32 |
| The same, with 9M of the input tokens cached | $2.78 (better) | $18.50 |
| Other listed rates | ||
| 1M input tokens, cached | $0.02 (better) | $0.50 |
Verdict
When to choose each
GPT-5.6 Luna
Where it leads
- Lower input and output prices, $0.20 and $1.20 vs $2 and $6 per 1M tokens
- Higher FrontierMath Tiers 1-3 (v2) score, 82.1% vs 66%
- Larger context window 1,050,000 vs 500,000 tokens
- Cheaper cached input, $0.02 vs $0.50 per 1M tokens
Best for
- High-volume API evaluation with published low token prices
- Subagents and batch reasoning where cost per call dominates
Watch out for
- Not in the pinned LiveBench snapshot; its independent scores here come from Epoch AI's own GPQA Diamond, FrontierMath and SimpleQA Verified runs
Grok 4.6
Where it leads
- Higher Arena Text score, 1454 Elo vs 1452 Elo
- Higher GPQA Diamond score, 94% vs 91.6%
- Higher SimpleQA Verified score, 49.3% vs 41%
Best for
- Coding, agentic, and knowledge-work API evaluations with controlled long-context cost
Watch out for
- Published token rates increase for all tokens in a request once its prompt reaches xAI's 200,000-token long-context threshold
From benchmark to production
Building on GPT-5.6 Luna or Grok 4.6?
Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.
FAQ
GPT-5.6 Luna vs Grok 4.6 FAQ
Which is cheaper, GPT-5.6 Luna or Grok 4.6?
GPT-5.6 Luna is 90% cheaper per 1M input tokens than Grok 4.6, $0.20 vs $2. For 10M input and 2M output tokens, GPT-5.6 Luna costs $4.40 and Grok 4.6 $32 at standard rates.
Which is cheaper with prompt caching, GPT-5.6 Luna or Grok 4.6?
GPT-5.6 Luna charges $0.02 per 1M cached input tokens, 90% below its standard input rate, and Grok 4.6 $0.50, 75% below. With 9M of 10M input tokens cached and 2M output tokens, GPT-5.6 Luna costs $2.78 and Grok 4.6 $18.50.
Which scores higher on independent benchmarks, GPT-5.6 Luna or Grok 4.6?
Grok 4.6 leads on Arena Text, 1454 Elo to 1452 Elo; Grok 4.6 leads on GPQA Diamond, 94% to 91.6%; GPT-5.6 Luna leads on FrontierMath Tiers 1-3 (v2), 82.1% to 66%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, GPT-5.6 Luna or Grok 4.6?
GPT-5.6 Luna has the larger context window, 1,050,000 vs 500,000 tokens.
Further reading
More on GPT-5.6 Luna and Grok 4.6
Articles on GPT-5.6 Luna and Grok 4.6
- Grok 4.7: Same Price as Grok 4.6, but Check Cost per TaskSeptember 22, 2026
- Grok 4.6 and Persistent VM AgentsAugust 13, 2026
- GPT-5.6 on Azure Databricks: Production Guide for AI TeamsJuly 11, 2026
- GPT-5.6 In Microsoft 365 Copilot: What Production Teams Should KnowJuly 10, 2026
- Unverified GPT-5.6 soft launch reports and what they mean for AI-assisted software engineering: what is confirmed?June 21, 2026
Related comparisons
- GPT-5.6 Luna vs GPT-6 Luna
- Claude Sonnet 5.5 vs Grok 4.6
- GPT-5.6 Luna vs GPT-6 Sol
- Grok 4.6 vs Grok 4.7
- Claude Opus 5 vs GPT-5.6 Luna
- Claude Sonnet 5 vs Grok 4.6
- Gemini 3.6 Flash vs GPT-5.6 Luna
- GPT-4.1 vs Grok 4.6
- GPT-5.6 Luna vs GPT-5.6 Sol
- Grok 4.20 vs Grok 4.6
- GPT-5.6 Luna vs GPT-5.6 Terra
- Grok 4.3 vs Grok 4.6
Production evaluation
Choosing between GPT-5.6 Luna and Grok 4.6?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty
