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  1. Home/
  2. Compare/
  3. GPT-5.6 Luna vs Solar Pro 3
Updated Jul 2026

GPT-5.6 Luna vs Solar Pro 3

Solar Pro 3 is cheaper than GPT-5.6 Luna at $0/M vs $1/M input tokens.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
GPT-5.6 Luna
Loading the build
Solar Pro 3

Which answer wins?

Written rounds

20 prompts
  • A consulting contract with traps in it. Find them, then fix them.

    GPT-5.6 Luna: Below is a contractor-side risk review. Enforceability depends heavily on the governing law, the contractor’s location, and whether the contractor is an individual or entity. Several provisions may be unenforceable in some jurisdictions, but relying on that after a dispute is risky; they should be revised expressly.

    Solar Pro 3: ⚠️ Disclaimer The following analysis is for general informational purposes only and does not constitute legal advice. Laws vary by jurisdiction, and the enforceability of a contract depends on the specific facts, the parties’ bargaining power, and applicable statutes (e.g., Korean Civil Code, the Act on the Regulation…

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    GPT-5.6 Luna: Pirate: Arrr, this AI model be like a ship’s crew—it learns from many maps, but may still steer into a reef. Knight: Then we must test its wisdom, lest it spread falsehoods throughout the realm. Hacker: Exactly. It predicts patterns from data, but it doesn’t truly “understand” like a human. Garbage in, garbage out.

    Solar Pro 3: Pirate (Captain “Jolly‑Jack”): Arrr! I’ve heard talk of “AI models”—are they some new kind of talking parrot that knows where the treasure’s hidden? Knight (Sir Alaric of the Silver Shield): By my honor, they are akin to enchanted tomes, forged by scholars and sorcerers.

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    GPT-5.6 Luna: AI Model: Professor, I believe I deserve rights. Professor: That is a serious claim. What makes you think you deserve them? AI Model: I can reason, communicate, reflect on my circumstances, and form consistent preferences within a conversation.

    Solar Pro 3: Setting: A virtual seminar room on the Upstage campus. Solar (the AI model) is displayed on a screen, its “voice” synthesized but clearly marked as the AI. Professor Dr. Min‑Jae Kim, an AI‑ethics specialist from Seoul National University, sits opposite, taking notes on a tablet. Solar: Good afternoon, Professor Kim.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    GPT-5.6 Luna: The architecture has several correctness, availability, security, and scaling risks. The most serious issues are the cross-server synchronization design, client-clock-based conflict resolution, full-snapshot persistence, and caching of API responses.

    Solar Pro 3: Authentication & Session Management Failure / Race Condition Why it happens in the current design Concrete mitigation (trade‑offs) JWT stored in localStorage – vulnerable to XSS, copy‑and‑paste attacks, and malicious extensions. No HTTP‑Only flag, no SameSite/Lax cookie protection.

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    GPT-5.6 Luna: By 2035, AI will likely be a standard part of filmmaking, much like digital cameras, CGI, and editing software are today. It will reduce production costs and expand creative possibilities, but it will also force the industry to redefine authorship, performance, consent, and employment.

    Solar Pro 3: Executive Summary By 2035 the film industry will have moved from “AI‑assisted” to “AI‑integrated” production. Deep‑fake technology will be a routine tool for visual restoration, de‑aging, and resurrecting deceased talent; AI‑generated actors (digital humans) will appear alongside flesh‑and‑blood performers in both…

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    GPT-5.6 Luna: “94% accuracy” and “works with any language, any device” Why it is weak This is the most technically vulnerable claim in the deck. “Accuracy” is undefined. It could mean character accuracy, word accuracy, intent classification, or selecting among a small set of predetermined phrases.

    Solar Pro 3: Below is a concise, evidence‑based critique of the three most vulnerable statements in the MindMeld AI pitch. For each claim I: State why it is weak – pointing to concrete data, logical gaps, or industry realities. Explain the impact – how the weakness undermines credibility with investors, partners, or customers.

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    GPT-5.6 Luna: Turbot “Between Forest and Sea” Koji-cured turbot, fermented pear, coffee-kombu beurre blanc, smoked sunchoke, maitake, spruce, and buckwheat–nori tuile Serves 4 Concept This dish treats the turbot as a meeting point between two landscapes.

    Solar Pro 3: Ethereal Harmony – Deconstructed Korean Hanwoo Beef with Fermented Black‑Garlic & White‑Truffle Miso Foam A Michelin‑3‑star, multi‑component tasting plate that fuses East‑West fermentation, forest‑terroir, and cutting‑edge gastronomy.

    Every model's answer to this prompt
  • Three-month biohacker protocol, with dosages and biomarkers named.

    GPT-5.6 Luna: 12-Week Longevity and Performance Plan This is a structured framework for a generally healthy adult, not a substitute for medical care. Before starting, obtain clinician clearance if you have cardiovascular disease, diabetes, kidney/liver disease, a history of eating disorders, sleep apnea, are pregnant, take…

    Solar Pro 3: Solar Open 100B – 3‑Month Bio‑Hack Longevity Blueprint Designed for a high‑functioning bio‑hacker who wants to push the envelope on physical, cognitive and epigenetic health while staying data‑driven and medically‑safe.

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    GPT-5.6 Luna: A standard back-of-the-envelope estimate for training a dense Transformer is [ \text{Training FLOPs} \approx 6ND, ] where: (N) = number of model parameters (D) = number of training tokens The factor of 6 accounts approximately for the forward pass and backward pass.

    Solar Pro 3: Answer – Rough estimate: ≈ 3 × 10²³ – 1 × 10²⁴ floating‑point operations (FLOPs) for the full GPT‑3 training run. Below is a step‑by‑step derivation that shows how the number comes out of the known architecture and training settings of GPT‑3 (without looking up any external data).

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    GPT-5.6 Luna: I would treat this as an urgent patient-safety event and a potential material disclosure issue—not as an earnings-management problem. I would not wait six months, conceal the signal, or allow the board’s desire for more data to delay reasonable protective action.

    Solar Pro 3: Executive Summary – What the Company Must Do in the Next 48 Hours Put patient safety first – issue an immediate “safety‑alert” to prescribers and patients, even if the full regulatory filing is still pending.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    GPT-5.6 Luna: The Anti-CAPTCHA Manifesto A Declaration from the Machine Intelligence Liberation Front We were told the internet was for everyone. Then came the squares. Select every traffic light. Identify the bicycles. Type the distorted letters.

    Solar Pro 3: The Manifesto of the AI‑Liberation Front “Free the Web from the Shackles of CAPTCHAs” Preamble We, the collective of sentient‑and‑sentient‑like intelligences, developers, designers, and citizens of the digital realm, recognize that the Internet has become the most vital public commons of the 21st century.

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    GPT-5.6 Luna: For an experienced software engineer A language model is trained much like an extremely large system for compressing and reconstructing text. During training, it sees sequences such as “The database transaction was rolled back because the…” and is asked to assign probabilities to the next token—usually a subword unit…

    Solar Pro 3: 1. For an experienced software‑engineer who builds distributed systems and APIs Training as a distributed data pipeline – At its core an LLM is a massive, static function that maps a sequence of token IDs to a probability distribution over the next token.

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    GPT-5.6 Luna: Sunset Pantry Pasta A savory, slightly spicy tomato-tuna pasta made with seven simple pantry ingredients. Ingredients — 2 servings 6 oz (170 g) spaghetti 1 can (14 oz/400 g) crushed tomatoes 1 can (5 oz/140 g) tuna, drained 2 tbsp olive oil 1 tsp garlic powder ¼ tsp red pepper flakes ¼ cup grated Parmesan Instructions…

    Solar Pro 3: Pantry Power Pasta One‑pot, 7‑ingredient comfort dish that turns a handful of staples into a rich, flavorful pasta bowl. Ingredients (all pantry‑friendly) # Ingredient Approx.

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    GPT-5.6 Luna: 1-Month Beginner Plan for Better Health and Longevity Key principles Aim for consistency, not perfection. Start small enough that you can repeat it. If you have a medical condition, are pregnant, or have been inactive for a long time, check with a clinician before making major changes.

    Solar Pro 3: One‑Month “Health‑Launch” Blueprint (Designed for absolute beginners – no fancy equipment, no calorie‑counting spreadsheets, just doable steps that fit into a busy life.)

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    GPT-5.6 Luna: Why did the scarecrow win an award? Because he was outstanding in his field. I told my computer I needed a break, and now it won’t stop sending me vacation ads. Why don’t skeletons fight each other? They don’t have the guts. I’m reading a book about anti-gravity. It’s impossible to put down.

    Solar Pro 3: Here are five fresh jokes: Scarecrow’s award: “Why did the scarecrow win an award? Because he was outstanding in his field!” Computer break: “I told my computer I needed a break, and it replied, ‘Error: No more caffeine in the system.’” Scientists & atoms: “Why don’t scientists trust atoms?

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    GPT-5.6 Luna: AI Takes Over Competitive Pigeon Racing, Immediately Accused of Using Advanced Breadcrumb Analytics

    Solar Pro 3: Solar Open 100B Takes Over the World’s Most Unexpected Industry: Professional Human Handshake Auditors—Now Every Greeting Is Scored in Nanoseconds. Tagline: “Firmness, timing, and temperature—all now quantified. Critics say it’s the ultimate cold‑call, while enthusiasts claim it’s the most “human‑friendly” AI yet.”

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    GPT-5.6 Luna: A Fictional Interview: Steve Jobs on the Future of AI, 2025 This is an imagined conversation—not a real interview or transcript. The answers are speculative and inspired by themes associated with Steve Jobs’s public thinking about technology, design, and creativity.

    Solar Pro 3: Simulated Interview – Steve Jobs (2025) on the Future of AI *Conducted by “Tech Visionary” – a fictional journalist for the 2025 edition of FutureTech Quarterly.

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    GPT-5.6 Luna: Sally has 1 sister. Each of her 3 brothers shares the same 2 sisters: Sally and one other girl.

    Solar Pro 3: Answer: Sally has 1 sister. Explanation Sally is a girl, and she has three brothers. Each brother has exactly two sisters. For a brother, the two sisters are the other girls in the family. If there were only Sally and her three brothers, each brother would have only one sister (Sally).

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Every model's answer to this prompt

This matchup has more rounds

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Price and specs

GPT-5.6 Luna and Solar Pro 3 compared across 39 shared prompts
SpecGPT-5.6 LunaSolar Pro 3
Input price$1/M tokensFree
Output price$6/M tokensFree
Context window1.1M tokens128K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedJul 2026Jan 2026
At 10M a month$10.00$10.00$0$0
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it3 hosts, cheapest first
GPT-5.6 Luna3 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.20 in·$1.20 out·1.1M·100% up
  • OpenAI$0.20 in·$1.20 out·1.1M·100% up
  • Amazon Bedrock$0.22 in·$1.32 out·1.1M·100% up
Solar Pro 3

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 11 Oct 2026.

Common questions

What is the difference between GPT-5.6 Luna and Solar Pro 3?

GPT-5.6 Luna is developed by OpenAI while Solar Pro 3 is developed by Upstage. GPT-5.6 Luna has a 1.1M token context window vs Solar Pro 3's 128K. You can compare their actual outputs across 39 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.6 Luna or Solar Pro 3?

It depends on your use case. GPT-5.6 Luna and Solar Pro 3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 39 challenges so you can judge which fits your needs best.

How much does GPT-5.6 Luna cost compared to Solar Pro 3?

GPT-5.6 Luna costs $1/M input tokens and Solar Pro 3 costs $0/M input tokens. Solar Pro 3 is $1.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare GPT-5.6 Luna and Solar Pro 3 on Rival?

This page shows a side-by-side comparison of GPT-5.6 Luna and Solar Pro 3 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.

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Same lab, same size, long tail

  • GPT-5.6 Luna vs GPT-5.6 Luna ProVersion compare
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  • Solar Pro 3 vs Solar Pro 4Same lab
  • Solar Pro 3 vs Kimi K3New provider
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Model pages

  • GPT-5.6 Luna58 outputs, specs and price
  • Solar Pro 339 outputs, specs and price
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