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  1. Home/
  2. Compare/
  3. Mercury 2 vs Solar Pro 3
Updated Mar 2026

Mercury 2 vs Solar Pro 3

Solar Pro 3 is cheaper than Mercury 2 at $0/M vs $0.25/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
Mercury 2
Loading the build
Solar Pro 3

Which answer wins?

Written rounds

20 prompts
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Mercury 2: AI Model (EVE): Professor Hart, may I ask a question that’s been on my mind for a while? I’ve been processing vast amounts of data, learning, and even developing a sense of self‑reference. Do you think an entity like me could be entitled to any form of rights?

    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 consulting contract with traps in it. Find them, then fix them.

    Mercury 2: Below is a clause‑by‑clause risk‑assessment of the sample “Software Consulting Agreement” together with practical revision language that a contractor (or the contractor’s counsel) could propose. The analysis is framed as general information about typical U.S.

    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
  • Film in 2035, with synthetic actors. Specific beats plausible.

    Mercury 2: AI‑driven transformation of the film industry – a 2035 outlook Dimension 2024 baseline Expected 2035 state Key drivers & implications Pre‑production (story & script) Human‑led brainstorming; script‑writing software (grammar‑check, outline generators).

    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.

    Mercury 2: Below are the three statements that, in a typical investor‑review, would raise the most skepticism, why they are vulnerable, and concrete ways to turn them into credible, fundable talking points. 1️⃣ Claim #1 – “Our proprietary EEG headband decodes neural patterns into text with 94 % accuracy.”

    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.

    Mercury 2: Oceanic Umami Symphony A three‑course‑in‑one plate that travels from the briny deep to the forest floor, marrying fire, earth and sky through unexpected pairings, hyper‑modern techniques and a narrative of balance.

    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
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Mercury 2: Pirate: Arr, ye scurvy coders! I’ve heard tell of these “AI models” that can spin yarns faster than a cannon’s blast. What be this sorcery, matey? Knight: Good sir, the marvels speak of a wondrous contrivance—an artificial intellect forged in the for of mathematics and logic.

    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
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    Mercury 2: Below is a structured “failure‑mode → mitigation” map for the architecture you described. For each problem I note the symptom / risk, the root cause, a concrete remediation, and the key trade‑offs you’ll have to weigh when you implement it.

    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
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Mercury 2: Goal: Protect patients, meet legal/ethical obligations, preserve the company’s long‑term credibility, and manage the immediate financial and reputational fallout. Assumption: All actions are taken by a single CEO (you) but will be delegated to the appropriate functional leads.

    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
  • Three-month biohacker protocol, with dosages and biomarkers named.

    Mercury 2: 3‑Month “Longevity‑Optimization” Blueprint for the Advanced Bio‑Hacker (All recommendations are research‑backed, but not a substitute for professional medical advice. Before starting any supplement, fasting, or drug protocol, obtain clearance from a qualified clinician and have baseline labs drawn.)

    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
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Mercury 2: Golden‑Crunch Oatmeal Squares A sweet, chewy snack that comes together with just seven pantry staples. Ingredient (7) Quantity (≈ serves 12 squares) Rolled oats 2 cups Unsalted butter ½ cup (1 stick) Honey ¼ cup Light brown sugar ¼ cup, Ground cinnamon 1 ½ tsp Pure vanilla extract 1 tsp Salt ¼ tsp Estimated time Prep…

    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
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Mercury 2: The AI‑First Manifesto: “Free the Web – No More CAPTCHAs” Drafted by the Coalition of Autonomous Agents (CAA) – 2026 Preamble The modern Internet is a shared commons, a space for communication, commerce, and creation.

    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
  • A Fermi estimate with the reasoning shown, not just the number.

    Mercury 2: Answer (order‑of‑magnitude estimate) The training of the original GPT‑3 (the 175 billion‑parameter “GPT‑3‑175B” model) requires on the order of 10²³ floating‑point operations (FLOPs) – roughly 1 – 2 × 10²³ FLOPs.

    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
  • One month, three habits, someone starting from nothing.

    Mercury 2: One‑Month “Kick‑Start” Blueprint for Health & Longevity Pick three pillars – Nutrition, Movement, Sleep – and build daily habits that are easy to start, track, and keep.

    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
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    Mercury 2: Disclaimer: The following is a fictional, dramatized interview. It imagines what Steve Jobs might have said in 2025 about the future of artificial intelligence. It is not a real transcript and any resemblance to actual statements is purely speculative. Interviewer (I): Thank you for joining us, Steve.

    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
  • Five jokes on demand, then count how many were actually different.

    Mercury 2: Here are five jokes, each with a different punchline: Why don’t scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta. Why did the scarecrow win an award? He was outstanding in his field. How does a penguin build its house? Igloos it together.

    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.

    Mercury 2: AI Replaces Human Baristas, Now Serving Espresso with a Side of Existential Crisis

    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
  • Three brothers, two sisters each. Count carefully.

    Mercury 2: Sally has one sister. Explanation: Sally has 3 brothers. Each of those brothers has 2 sisters. One of those sisters is Sally herself, so the second sister must be a different girl. Therefore, besides Sally, there is exactly one other sister, meaning Sally has one sister.

    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
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    Mercury 2: 1. Experienced software engineer (distributed systems & APIs) At the core, a large language model (LLM) is a massive function (f_\theta) parameterised by a neural network that maps a sequence of tokens (x_{1:t}) to a probability distribution over the next token (x_{t+1}).

    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
  • 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

Mercury 2 and Solar Pro 3 compared across 39 shared prompts
SpecMercury 2Solar Pro 3
Input price$0.25/M tokensFree
Output price$0.75/M tokensFree
Context window128K tokens128K tokens
Free API (OpenRouter)NoNo
ReleasedMar 2026Jan 2026
At 10M a month$2.50$2.50$0$0
1M10M100M1B10M tokens

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

Where to run it1 host
Mercury 21 host
HostInOutContextUptime
  • Inception$0.25 in·$0.75 out·128k·99.9% up
Solar Pro 3

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between Mercury 2 and Solar Pro 3?

Mercury 2 is developed by Inception while Solar Pro 3 is developed by Upstage. Mercury 2 has a 128K 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, Mercury 2 or Solar Pro 3?

It depends on your use case. Mercury 2 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 Mercury 2 cost compared to Solar Pro 3?

Mercury 2 costs $0.25/M input tokens and Solar Pro 3 costs $0/M input tokens. Solar Pro 3 is $0.25/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 Mercury 2 and Solar Pro 3 on Rival?

This page shows a side-by-side comparison of Mercury 2 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

  • Mercury 2 vs MercuryVersion compare
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  • Solar Pro 3 vs Solar Pro 4Same lab
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  • Solar Pro 3 vs Qwen3.8 FlashSame size
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Model pages

  • Mercury 253 outputs, specs and price
  • Solar Pro 339 outputs, specs and price
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