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Gemini 4 Carbon vs GPT-5.6 Luna

Gemini 4 Carbon leads the LLM Stats Score 59.0 to 43.9.

Google · OpenAI · Updated for 2026

Which is better?

Gemini 4 Carbon leads the overall LLM Stats Score 59.0 to 43.9, ranking #2 overall.

In the 4 individual benchmarks reported for both models, Gemini 4 Carbon wins 4; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Gemini 4 Carbon

  • overall performance matters — it scores 59.0 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 4 of 4 exact shared results
  • you want the most recent training data — it shipped Oct 2026

Choose GPT-5.6 Luna

  • you want predictable pricing at $0.20/M input and $1.20/M output

At a glance

The differences that matter most.

Gemini 4 Carbon
Google
GPT-5.6 Luna
OpenAI
Core performance indexes
LLM Stats Score
59.0
#2
43.9
#54
Reasoning
54.9
#5
42.5
#58
Coding
48.1
#3
34.0
#42
Agents
46.0
#2
30.1
#52
Cost, coverage & limits
Benchmark wins
4 of 4
0 of 4
Input price
— / M
$0.20 / M
Output price
— / M
$1.20 / M
Context window
—
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

4 shared
Index
Gemini 4 Carbon
GPT-5.6 Luna
Vision
36.0#12
24.0#72
Tool use
35.8#3
23.4#51
Multimodal
38.0#6
24.4#69
Safety
33.0#1
15.8#14
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

16 reported for Gemini 4 Carbon · 45 for GPT-5.6 Luna

4 shared

Gemini 4 Carbon outperforms in 4 benchmarks (AutomationBench, ExploitGym, Graphwalks BFS >128k, SEC-bench Pro), while GPT-5.6 Luna is better at 0 benchmarks.

Gemini 4 Carbon significantly outperforms across most benchmarks.

Fri Oct 30 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

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).

Google
Gemini 4 Carbon
Input- tokens
Output- tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Fri Oct 30 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 4 Carbon and GPT-5.6 Luna support multimodal inputs.

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

Gemini 4 Carbon

Text
Images
Audio
Video

GPT-5.6 Luna

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.

Gemini 4 Carbon

Proprietary

Closed source

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 4 Carbon was released on 2026-10-28, while GPT-5.6 Luna was released on 2026-07-09.

Gemini 4 Carbon is 4 months newer than GPT-5.6 Luna.

Gemini 4 Carbon

Oct 28, 2026

1 days ago

3mo newer
GPT-5.6 Luna

Jul 9, 2026

3 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Gemini 4 Carbon'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 Gemini 4 Carbon's cutoff date.

Gemini 4 Carbon

—

GPT-5.6 Luna

Feb 2026

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Gemini 4 Carbon and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

Gemini 4 Carbon
✓ Preferred
GPT-5.6 Luna
Open in Playground

FAQ

Common questions about Gemini 4 Carbon vs GPT-5.6 Luna.

Which is better, Gemini 4 Carbon or GPT-5.6 Luna?

Gemini 4 Carbon leads the LLM Stats Score 59.0 to 43.9. Gemini 4 Carbon is made by Google and GPT-5.6 Luna is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 4 Carbon compare to GPT-5.6 Luna in benchmarks?

Gemini 4 Carbon scores Gray Swan IPI Benchmark: 100.0%, Vending-Bench 2: 100.0%, Graphwalks BFS >128k: 96.2%, WebDev Arena: 88.4%, SEC-bench Pro: 88.2%. 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%.

What are the context window sizes for Gemini 4 Carbon and GPT-5.6 Luna?

Gemini 4 Carbon supports an unknown number of tokens and GPT-5.6 Luna supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 4 Carbon and GPT-5.6 Luna?

Key differences include LLM Stats Score (59.0 vs 43.9). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 4 Carbon and GPT-5.6 Luna?

Gemini 4 Carbon is developed by Google and GPT-5.6 Luna is developed by OpenAI.

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