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GPT-6 Luna vs Kimi K2.5

GPT-6 Luna leads the LLM Stats Score 44.5 to 38.8. GPT-6 Luna is 6.0x cheaper per token.

OpenAI · Moonshot AI · Updated for 2026

Which is better?

GPT-6 Luna leads the overall LLM Stats Score 44.5 to 38.8, ranking #41 overall.

On price, GPT-6 Luna is roughly 6.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-6 Luna also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose GPT-6 Luna

  • overall performance matters — it scores 44.5 and ranks #41 on LLM Stats
  • your work emphasizes coding and agents — it leads those capability indexes
  • cost matters — it's about 6.0x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose Kimi K2.5

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

GPT-6 Luna
OpenAI
Kimi K2.5
Moonshot AI
Core performance indexes
LLM Stats Score
44.5
#41
38.8
#67
Reasoning
40.0
#58
38.6
#65
Coding
31.4
#47
25.0
#77
Agents
31.8
#30
18.1
#75
Cost, coverage & limits
Benchmark wins
—
—
Input price
$0.10 / M
$0.60 / M
Output price
$0.50 / M
$3.00 / M
Context window
1,050,000
262,100

Individual benchmarks

5 reported for GPT-6 Luna · 40 for Kimi K2.5

No common benchmarks found

GPT-6 Luna and Kimi K2.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-6 Luna costs less

For input processing, GPT-6 Luna ($0.10/1M tokens) is 6.0x cheaper than Kimi K2.5 ($0.60/1M tokens).

For output processing, GPT-6 Luna ($0.50/1M tokens) is 6.0x cheaper than Kimi K2.5 ($3.00/1M tokens).

In conclusion, Kimi K2.5 is more expensive than GPT-6 Luna.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Sep 23 2026 • llm-stats.com
OpenAI
GPT-6 Luna
Input tokens$0.10
Output tokens$0.50
Best providerOpenAI
Moonshot AI
Kimi K2.5
Input tokens$0.60
Output tokens$3.00
Best providerFireworks
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-6 Luna accepts 1,050,000 input tokens compared to Kimi K2.5's 262,100 tokens. Kimi K2.5 can generate longer responses up to 262,100 tokens, while GPT-6 Luna is limited to 128,000 tokens.

OpenAI
GPT-6 Luna
Input1,050,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2.5
Input262,100 tokens
Output262,100 tokens
Wed Sep 23 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-6 Luna and Kimi K2.5 support multimodal inputs.

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

GPT-6 Luna

Text
Images
Audio
Video

Kimi K2.5

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-6 Luna is licensed under a proprietary license, while Kimi K2.5 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-6 Luna

Proprietary

Closed source

Kimi K2.5

MIT

Open weights

Release Timeline

When each model was launched

GPT-6 Luna was released on 2026-09-22, while Kimi K2.5 was released on 2026-01-27.

GPT-6 Luna is 8 months newer than Kimi K2.5.

GPT-6 Luna

Sep 22, 2026

0 days ago

7mo newer
Kimi K2.5

Jan 27, 2026

7 months ago

Knowledge Cutoff

When training data ends

GPT-6 Luna has a documented knowledge cutoff of 2026-05-18, while Kimi K2.5's cutoff date is not specified.

We can confirm GPT-6 Luna's training data extends to 2026-05-18, but cannot make a direct comparison without Kimi K2.5's cutoff date.

GPT-6 Luna

May 2026

Kimi K2.5

—

Provider Availability

GPT-6 Luna is available from OpenAI. Kimi K2.5 is available from Fireworks, Moonshot AI.

GPT-6 Luna

openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M

Kimi K2.5

fireworks logo
Fireworks
Input Price:Input: $0.60/1MOutput Price:Output: $3.00/1M
moonshot logo
Unknown Organization
Input Price:Input: $0.60/1MOutput Price:Output: $3.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against GPT-6 Luna and Kimi K2.5 side-by-side, then vote on the output you prefer.

GPT-6 Luna
✓ Preferred
Kimi K2.5
Open in Playground

FAQ

Common questions about GPT-6 Luna vs Kimi K2.5.

Which is better, GPT-6 Luna or Kimi K2.5?

GPT-6 Luna leads the LLM Stats Score 44.5 to 38.8. GPT-6 Luna is made by OpenAI and Kimi K2.5 is made by Moonshot AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-6 Luna compare to Kimi K2.5 in benchmarks?

GPT-6 Luna scores DeepSWE 1.1: 66.6%, OSWorld 2.0: 52.7%, Agents' Last Exam: 50.9%, FrontierCode 1.1: 42.4%, AutomationBench v1.0.6: 20.7%. Kimi K2.5 scores AIME 2025: 96.1%, HMMT 2025: 95.4%, InfoVQAtest: 92.6%, OCRBench: 92.3%, MathVista-Mini: 90.1%.

Is GPT-6 Luna cheaper than Kimi K2.5?

GPT-6 Luna is 6.0x cheaper for input tokens. GPT-6 Luna costs $0.10/M input and $0.50/M output via openai. Kimi K2.5 costs $0.60/M input and $3.00/M output via fireworks.

What are the context window sizes for GPT-6 Luna and Kimi K2.5?

GPT-6 Luna supports 1.1M tokens and Kimi K2.5 supports 262K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-6 Luna and Kimi K2.5?

Key differences include LLM Stats Score (44.5 vs 38.8), context window (1.1M vs 262K), input pricing ($0.10 vs $0.60/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-6 Luna and Kimi K2.5?

GPT-6 Luna is developed by OpenAI and Kimi K2.5 is developed by Moonshot AI.

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