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 Luna ProvsGrok 4.20 Multi-Agent Beta
Updated Sep 2026

GPT-6 Luna ProvsGrok 4.20 Multi-Agent Beta

GPT-6 Luna Pro is cheaper than Grok 4.20 Multi-Agent Beta at $0.1/M vs $2/M input tokens.

GPT-6 Luna Pro and Grok 4.20 Multi-Agent Beta compared across 20 shared prompts
SpecGPT-6 Luna ProGrok 4.20 Multi-Agent Beta
Input price$0.1/M tokens$2/M tokens
Output price$0.5/M tokens$6/M tokens
Context window1.1M tokens2.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedSep 2026Mar 2026
Side by side

Same prompt, both answers

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

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 Luna Pro2,057 words
12-week longevity and performance plan This is a structured starting plan for a generally healthy adult—not a diagnosis or a substitute for medical care. The best longevity interventions are still the unglamorous ones: not smoking, regular exercise, adequate sleep, a high-quality diet, healthy blood pressure and…
Read the full answer
Grok 4.20 Multi-Agent Beta1,254 words
Comprehensive 3-Month Cutting-Edge Longevity Biohacker Plan (as of 2026 knowledge) Important Disclaimers: This is a synthesized, educational plan based on current longevity research (e.g., insights from David Sinclair, Valter Longo, Peter Attia, and studies on NAD+, senolytics, mitophagy, HRV, and metabolic…
Read the full answer

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 Luna Pro127 words
Golden Pantry Pancakes Fluffy, lightly sweet pancakes made with everyday staples. Makes: About 6 small pancakes Prep time: 5 minutes Cook time: 10 minutes Ingredients 1 cup all-purpose flour 1 cup milk 1 egg 2 tablespoons sugar 1 teaspoon baking powder ¼ teaspoon salt 2 tablespoons butter, melted (plus a little for the…
Read the full answer
Grok 4.20 Multi-Agent Beta188 words
Fiesta Pantry Bowl (Savory) 7 Common Pantry Ingredients: Rice Canned black beans Canned corn Canned diced tomatoes Olive oil Cumin Salt Estimated times: 5 minutes prep, 25 minutes cook (total ~30 minutes). Serves 2–4. Instructions: In a medium pot, combine 1 cup rice with 2 cups water and ½ tsp salt.
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 Luna Pro1,906 words
The main architectural risk is that this design treats collaborative editing as ordinary “last write wins” data storage. It is not: edits need a well-defined order, reliable propagation, and a conflict model that preserves concurrent work.
Read the full answer
Grok 4.20 Multi-Agent Beta1,103 words
Here is a comprehensive analysis of the failure modes, race conditions, and scaling bottlenecks in the described architecture. I have grouped related issues for clarity while preserving all significant problems identified through team collaboration.
Read the full answer

Startup Pitch Teardown

Here's a pitch deck summary for a startup called "MindMeld AI": **Slide 1 - Vision:** "We're building the future of human-AI collaboration.…

GPT-6 Luna Pro401 words
“94% accuracy” and “works with any language, any device” Why it’s weak: “Accuracy” is undefined. It could mean classifying a small set of prompted words in a controlled lab—not reliably generating free-form text.
Read the full answer
Grok 4.20 Multi-Agent Beta559 words
The 3 weakest claims are: 1. "Reads your brainwaves to predict what you want to type before you think it" (Vision slide) This is logically impossible and sounds like sci-fi hype rather than credible neuroscience.
Read the full answer

Michelin Star Recipe Design

Design an innovative recipe for a multi-component dish worthy of a Michelin 3-star restaurant. The recipe should feature an unusual…

GPT-6 Luna Pro1,215 words
Turbot, Sea Buckthorn, Mussel Beurre Blanc, and Celery-Root Silk Serves 4 A composed main course built around an unusual but harmonious pairing: briny mussel and turbot with intensely tart, apricot-like sea buckthorn.
Read the full answer
Grok 4.20 Multi-Agent Beta946 words
Dish Name: "Siren's Lament" Conceptual Narrative: This dish draws from the Greek myth of the siren—whose enchanting song lures sailors to their doom—symbolizing the irresistible yet perilous pull between the forest and the sea.
Read the full answer

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

GPT-6 Luna Pro434 words
Operating and debt schedule Conventions: Interest is calculated on beginning-of-year debt; the 1% Term Loan amortization is 1% of its original $480m principal ($4.8m annually). Mezzanine PIK accrues at 2% annually.
Read the full answer
Grok 4.20 Multi-Agent Beta490 words
1) Simplified LBO table (FY2026–2030, $m, rounded) Entry (end-FY2025): Rev $900m, EBITDA $120m, EV $1,440m (12.0x), trans fees $28.8m (2% of EV), total uses $1,468.8m. Debt $660m (TL $480m at 4.0x / 9% cash int / 1% annual amort of orig principal; Mezz $180m at 1.5x / 12% cash + 2% PIK). Equity $808.8m.
Read the full answer
Our Verdict
Grok 4.20 Multi-Agent Beta
Grok 4.20 Multi-Agent Beta
GPT-6 Luna Pro
GPT-6 Luna ProRunner-up

Not enough votes to call it. On the specs, Grok 4.20 Multi-Agent Beta has the edge: bigger model tier, bigger context window.

GPT-6 Luna Pro costs 12x 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 Pro
Input
$0.10
20× cheaper
Output
$0.50
12× cheaper
Grok 4.20 Multi-Agent Beta
Input
$2.00
Output
$6.00

GPT-6 Luna Pro is cheaper on both: 20× input, 12× output.

Where to run it

3 hosts

GPT-6 Luna Pro2 hosts
HostInOutContextUptime
Azure AI Foundry$0.10 in·$0.50 out·1.1M·98.6% upOpenAI$0.10 in·$0.50 out·1.1M·99.9% up
Grok 4.20 Multi-Agent Beta1 host
HostInOutContextUptime
xAI$1.25 in·$2.50 out·2M·80% 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 Pro is developed by OpenAI while Grok 4.20 Multi-Agent Beta is developed by xAI. GPT-6 Luna Pro has a 1.1M token context window vs Grok 4.20 Multi-Agent Beta's 2.0M. 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 Pro and Grok 4.20 Multi-Agent Beta 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 Pro costs $0.1/M input tokens and Grok 4.20 Multi-Agent Beta costs $2/M input tokens. GPT-6 Luna Pro is $1.90/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 Pro and Grok 4.20 Multi-Agent Beta 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 Pro logoSolar Mini 4 logo
GPT-6 Luna Pro vs Solar Mini 4Landed Sep 2026
Grok 4.20 Multi-Agent Beta logoQwen3.8 Max Prime logo
Grok 4.20 Multi-Agent Beta vs Qwen3.8 Max PrimeLanded Sep 2026
GPT-6 Luna Pro logoGLM 5.3 Prime logo
GPT-6 Luna Pro vs GLM 5.3 PrimeLanded Sep 2026
Grok 4.20 Multi-Agent Beta logoQwen3.8 Omni Flash logo
Grok 4.20 Multi-Agent Beta vs Qwen3.8 Omni FlashLanded Sep 2026
GPT-6 Luna Pro logoCommand A+ logo
GPT-6 Luna Pro vs Command A+Landed Sep 2026
Grok 4.20 Multi-Agent Beta logoClaude Opus 5.5 logo
Grok 4.20 Multi-Agent Beta vs Claude Opus 5.5Landed Sep 2026
GPT-6 Luna Pro logoGPT-6 Sol Pro logo
GPT-6 Luna Pro vs GPT-6 Sol ProLanded Sep 2026
Grok 4.20 Multi-Agent Beta logoGPT-6 Luna logo
Grok 4.20 Multi-Agent Beta vs GPT-6 LunaLanded Sep 2026

Same lab, same size, long tail

GPT-6 Luna Pro logoGPT-6 Luna logo
GPT-6 Luna Pro vs GPT-6 LunaSame lab
GPT-6 Luna Pro logoGPT-6 Sol logo
GPT-6 Luna Pro vs GPT-6 SolSame lab
Grok 4.20 Multi-Agent Beta logoGrok 4.20 Beta logo
Grok 4.20 Multi-Agent Beta vs Grok 4.20 BetaVersion compare
Grok 4.20 Multi-Agent Beta logoGrok 4.7 logo
Grok 4.20 Multi-Agent Beta vs Grok 4.7Same lab
GPT-6 Luna Pro logoClaude Sonnet 4 logo
GPT-6 Luna Pro vs Claude Sonnet 4Same size
GPT-6 Luna Pro logoClaude Sonnet 4.6 logo
GPT-6 Luna Pro vs Claude Sonnet 4.6Same size
GPT-6 Luna Pro logoClaude Sonnet 5 logo
GPT-6 Luna Pro vs Claude Sonnet 5Same size
Grok 4.20 Multi-Agent Beta logoOpenAI Codex Mini logo
Grok 4.20 Multi-Agent Beta vs OpenAI Codex MiniCross-provider

Model pages

GPT-6 Luna Pro logo
GPT-6 Luna Pro20 outputs, specs and price
Grok 4.20 Multi-Agent Beta logo
Grok 4.20 Multi-Agent Beta53 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