GPT-5.6 Luna vs Kimi K3.1 Pro
Kimi K3.1 Pro leads the LLM Stats Score 55.5 to 43.9. GPT-5.6 Luna is 8.9x cheaper per token.
OpenAI · Moonshot AI · Updated for 2026
Which is better?
Kimi K3.1 Pro leads the overall LLM Stats Score 55.5 to 43.9, ranking #5 overall.
In the 12 individual benchmarks reported for both models, Kimi K3.1 Pro wins 11; this is a narrower head-to-head signal than the composite indexes.
On price, GPT-5.6 Luna is roughly 8.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 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-5.6 Luna
- cost matters — it's about 8.9x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
Choose Kimi K3.1 Pro
- overall performance matters — it scores 55.5 and ranks #5 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 11 of 12 exact shared results
- you want the most recent training data — it shipped Oct 2026
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
45 reported for GPT-5.6 Luna · 30 for Kimi K3.1 Pro
GPT-5.6 Luna outperforms in 1 benchmarks (Agents' Last Exam), while Kimi K3.1 Pro is better at 11 benchmarks (BenchCAD, BenchCAD (with Python tool), BrowseComp, DeepSWE, ExploitBench, ExploitGym, GDP.pdf, GPQA, MMMU-Pro, MMMU-Pro (with tools), Terminal-Bench 4.0).
Kimi K3.1 Pro significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Luna ($0.20/1M tokens) is 10.0x cheaper than Kimi K3.1 Pro ($2.00/1M tokens).
For output processing, GPT-5.6 Luna ($1.20/1M tokens) is 8.3x cheaper than Kimi K3.1 Pro ($10.00/1M tokens).
In conclusion, Kimi K3.1 Pro is more expensive than GPT-5.6 Luna.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Luna accepts 1,050,000 input tokens compared to Kimi K3.1 Pro's 1,048,576 tokens. Kimi K3.1 Pro can generate longer responses up to 1,048,576 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.6 Luna and Kimi K3.1 Pro support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Luna
Kimi K3.1 Pro
Release Timeline
When each model was launched
GPT-5.6 Luna was released on 2026-07-09, while Kimi K3.1 Pro was released on 2026-10-23.
Kimi K3.1 Pro is 4 months newer than GPT-5.6 Luna.
Jul 9, 2026
3 months ago
Oct 23, 2026
6 days ago
3mo newerKnowledge Cutoff
When training data ends
GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Kimi K3.1 Pro'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 Kimi K3.1 Pro's cutoff date.
Feb 2026
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Provider Availability
GPT-5.6 Luna is available from OpenAI. Kimi K3.1 Pro is available from Moonshot AI.
GPT-5.6 Luna
Kimi K3.1 Pro
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Luna and Kimi K3.1 Pro side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Luna vs Kimi K3.1 Pro.