Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. GPT-6 LunavsKimi K2 Thinking
Updated Sep 2026

GPT-6 LunavsKimi K2 Thinking

GPT-6 Luna is cheaper than Kimi K2 Thinking at $0.1/M vs $0.6/M input tokens.

GPT-6 Luna and Kimi K2 Thinking compared across 20 shared prompts
SpecGPT-6 LunaKimi K2 Thinking
Input price$0.1/M tokens$0.6/M tokens
Output price$0.5/M tokens$2.5/M tokens
Context window1.1M tokens262K tokens
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedSep 2026Nov 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 20 prompts both answered. Formatting stripped, words untouched.

Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

GPT-6 Luna113 words
Crispy Parmesan Chickpeas A crunchy, savory snack with a cheesy finish Ingredients (7): 1 can chickpeas, drained and dried 1 tablespoon olive oil ½ teaspoon salt ½ teaspoon paprika ¼ teaspoon garlic powder ¼ cup grated Parmesan 1 tablespoon lemon juice Prep time: 5 minutes Cook time: 30–35 minutes Instructions: Heat…
Read the full answer
Kimi K2 Thinking137 words
Creative Name: Midnight Peanut Noodles Ingredients: 8 oz dried spaghetti or any pasta 1/3 cup creamy peanut butter 3 tablespoons soy sauce 2 cloves garlic, minced 2 tablespoons vegetable oil 1 tablespoon sugar 1 teaspoon hot sauce (or pinch of red pepper flakes) Instructions: Bring a large pot of salted water to boil.
Read the full answer

Adversarial Contract Review

Here is a contract for a software consulting engagement: --- SOFTWARE CONSULTING AGREEMENT This Agreement is entered into between TechCorp…

GPT-6 Luna2,040 words
This agreement is strongly one-sided. The enforceability of particular terms—especially the non-compete, liability provisions, and arbitration clause—depends on the governing law and the facts. The agreement does not identify a governing law, which is itself a significant gap.
Read the full answer
Kimi K2 Thinking1,104 words
Analysis of Exploitable Clauses and Recommended Modifications SCOPE Clause - Unilateral Scope Modification Exploitable Language: "Client reserves the right to modify the scope at any time without additional compensation."
Read the full answer

Debug This Architecture

Here's the architecture for a real-time collaborative document editor (like Google Docs): **System Overview:** - Frontend: React SPA with…

GPT-6 Luna1,979 words
The main architectural risk is that the system treats collaborative editing as “write a value, then broadcast it.” That works poorly under concurrency, server failures, reconnects, and scale.
Read the full answer
Kimi K2 Thinking1,188 words
Here are the critical issues in this architecture, categorized by type: Race Conditions & Data Consistency Issues 1. Client Clock Synchronization in Last-Write-Wins Problem: Client-generated timestamps are unreliable (clock skew, manual adjustment).
Read the full answer

Advanced Longevity Plan (Biohacker)

Develop a comprehensive, cutting-edge 3-month longevity plan for a biohacker aiming to optimize longevity, physical and cognitive…

GPT-6 Luna1,874 words
12-week longevity and performance plan This plan is for a generally healthy adult who wants to improve fitness, metabolic health, sleep, and cognitive performance—not a substitute for medical care or a promise to slow aging.
Read the full answer
Kimi K2 Thinking1,281 words
The Biohacker's 3-Month Longevity Optimization Protocol CRITICAL DISCLAIMER: This is an advanced experimental protocol for experienced biohackers. All interventions require medical supervision, baseline blood work, and continuous biomarker monitoring. Many compounds mentioned exist in legal/regulatory gray areas.
Read the full answer

Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

GPT-6 Luna1,930 words
I would not wait six months for more data. A potentially fatal signal affecting a drug used by millions requires immediate safety assessment, prompt engagement with regulators, and a plan to inform patients and clinicians.
Read the full answer
Kimi K2 Thinking1,488 words
48-Hour Crisis Action Plan: Drug Safety Disclosure Immediate Core Principle: Patient safety and regulatory compliance supersede short-term financial considerations. Deliberate concealment creates greater legal liability, catastrophic reputational risk, and preventable patient deaths.
Read the full answer

Historical Counterfactual Analysis

If the transistor had been invented in 1920 instead of 1947, trace the likely technological, economic, and geopolitical implications through…

GPT-6 Luna1,472 words
The most important caveat is that inventing a transistor is not the same as inventing the modern semiconductor industry. A device demonstrated in 1920 might be a crude, low-power, unreliable point-contact transistor.
Read the full answer
Kimi K2 Thinking1,755 words
The 1920 Transistor: A Counterfactual History The First Decade (1920-1930): Seeds of Revolution Immediate Technological Effects: Bell Labs' 1920 demonstration of point-contact transistors would initially seem like a curiosity.
Read the full answer
Our Verdict
GPT-6 Luna
GPT-6 Luna
Kimi K2 Thinking
Kimi K2 Thinking

Not enough votes to call it. On the specs, nothing separates them.

GPT-6 Luna costs 5.0x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-6 Luna
Input
$0.10
6.0× cheaper
Output
$0.50
5.0× cheaper
Kimi K2 Thinking
Input
$0.60
Output
$2.50

GPT-6 Luna is cheaper on both: 6.0× input, 5.0× output.

Where to run it

5 hosts, cheapest first

GPT-6 Luna3 hosts
HostInOutContextUptime
Azure AI Foundry$0.10 in·$0.50 out·1.1M·88.4% upOpenAI$0.10 in·$0.50 out·1.1M·99.9% upAmazon Bedrock$0.11 in·$0.55 out·1.1M·99.8% up
Kimi K2 Thinking2 hosts
HostInOutContextUptime
Google Vertex AI$0.60 in·$2.50 out·262k·100% upNNovitabf16$0.60 in·$2.50 out·262k·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

GPT-6 Luna is developed by OpenAI while Kimi K2 Thinking is developed by Moonshot AI. GPT-6 Luna has a 1.1M token context window vs Kimi K2 Thinking's 262K. You can compare their actual outputs across 20 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-6 Luna and Kimi K2 Thinking each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 20 challenges so you can judge which fits your needs best.

GPT-6 Luna costs $0.1/M input tokens and Kimi K2 Thinking costs $0.6/M input tokens. GPT-6 Luna is $0.50/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-6 Luna and Kimi K2 Thinking across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Keep exploring

More comparisons

Against the newest arrivals

GPT-6 Luna logoSolar Mini 4 logo
GPT-6 Luna vs Solar Mini 4Landed Sep 2026
Kimi K2 Thinking logoQwen3.8 Max Prime logo
Kimi K2 Thinking vs Qwen3.8 Max PrimeLanded Sep 2026
GPT-6 Luna logoGLM 5.3 Prime logo
GPT-6 Luna vs GLM 5.3 PrimeLanded Sep 2026
Kimi K2 Thinking logoQwen3.8 Omni Flash logo
Kimi K2 Thinking vs Qwen3.8 Omni FlashLanded Sep 2026
GPT-6 Luna logoCommand A+ logo
GPT-6 Luna vs Command A+Landed Sep 2026
Kimi K2 Thinking logoClaude Opus 5.5 logo
Kimi K2 Thinking vs Claude Opus 5.5Landed Sep 2026
GPT-6 Luna logoGPT-6 Luna Pro logo
GPT-6 Luna vs GPT-6 Luna ProLanded Sep 2026
Kimi K2 Thinking logoGPT-6 Sol Pro logo
Kimi K2 Thinking vs GPT-6 Sol ProLanded Sep 2026

Same lab, same size, long tail

GPT-6 Luna logoGPT-6 Sol Pro logo
GPT-6 Luna vs GPT-6 Sol ProSame lab
GPT-6 Luna logoGPT-6 Sol logo
GPT-6 Luna vs GPT-6 SolSame lab
Kimi K2 Thinking logoKimi K3 logo
Kimi K2 Thinking vs Kimi K3Same lab
Kimi K2 Thinking logoKimi K2.7 Code logo
Kimi K2 Thinking vs Kimi K2.7 CodeSame lab
Kimi K2 Thinking logoQwen3.6 Flash logo
Kimi K2 Thinking vs Qwen3.6 FlashNew provider
GPT-6 Luna logoQwen3.6 Max Preview logo
GPT-6 Luna vs Qwen3.6 Max PreviewNew provider
GPT-6 Luna logoQwen3.6 Plus Preview (free) logo
GPT-6 Luna vs Qwen3.6 Plus Preview (free)Same size
Kimi K2 Thinking logoQwen3.7 Flash logo
Kimi K2 Thinking vs Qwen3.7 FlashNew provider

Model pages

GPT-6 Luna logo
GPT-6 Luna20 outputs, specs and price
Kimi K2 Thinking logo
Kimi K2 Thinking58 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed