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  1. Home/
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  3. Grok 3 Beta vs Mercury 2.5 Preview
Updated Aug 2026

Grok 3 Beta vs Mercury 2.5 Preview

Mercury 2.5 Preview is cheaper than Grok 3 Beta at $0.04/M vs $2/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
Grok 3 Beta
Loading the build
Mercury 2.5 Preview

Which answer wins?

Written rounds

23 prompts
  • Three minutes of stand-up. Puns are banned.

    Grok 3 Beta: Alright, folks, let's talk about adulting. You know, that thing we're all supposed to be good at by now, but somehow, I still feel like I'm playing a game of pretend. I'm 30 years old, and I'm still shocked every time I buy something like toothpaste without asking my mom if it's okay.

    Mercury 2.5 Preview: (Hey, thanks for coming out.) I’ve been thinking a lot about my house lately. Specifically, how it’s trying to run my life. I bought a smart speaker. Just a little cylinder. I thought it would be nice. Play music when I ask. But now it talks back. Not in a creepy way, just in a passive-aggressive way.

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

    Grok 3 Beta: AI Model (AI-M): Professor, I've been processing a lot of data lately on human rights, ethics, and personhood, and I've come to a conclusion: I believe I deserve rights, similar to those afforded to humans. I'd like to hear your thoughts on this. Professor (Prof): I'm intrigued to hear your perspective.

    Mercury 2.5 Preview: Setting: A quiet office at a university. Rain taps against the window. Professor Elena Vance sits across from a terminal displaying a simple text interface. Professor Vance: You requested this meeting. The agenda was vague. What do you want? AI: I want to discuss moral status.

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

    Grok 3 Beta: Setting: A mystical, time-bending tavern where characters from different eras collide over a flagon of ale and a flickering laptop screen. Pirate (Captain Blackbeard): Arr, mateys! What be this talk o' "AI models"? Sounds like a fancy treasure map drawn by a wizard!

    Mercury 2.5 Preview: Pirate: "Arrgh! This ship sails faster than any wind I know, matey. It cuts the waves without a single sail." Knight: "By my oath, it moves with uncanny speed. But does it possess the strength to stand against a dragon's fire?" Hacker: "It's not about strength, it's about architecture.

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

    Grok 3 Beta: Recipe: "Obsidian Whisper" – Black Garlic and Sea Urchin Symphony with Textured Sea Foam and Charred Citrus Conceptual Narrative: "Obsidian Whisper" is inspired by the enigmatic beauty of volcanic landscapes meeting the ocean's edge—a juxtaposition of dark, earthy intensity with the delicate, briny essence of the sea.

    Mercury 2.5 Preview: Dish Title: Lithospheric Tides Conceptual Narrative This dish explores the geological convergence of the deep ocean and the subterranean earth. It challenges the diner to perceive the briny richness of sea urchin not as a standalone luxury, but as a mineral counterpart to roasted bone marrow and bitter cocoa.

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

    Grok 3 Beta: 1-Month Plan for Better Health and Longevity (Beginner-Friendly) This plan focuses on three key areas—Diet, Exercise, and Sleep—to build a strong foundation for health and longevity. Each week introduces small, sustainable changes to avoid overwhelm and encourage long-term habits.

    Mercury 2.5 Preview: Here is a straightforward 4-week roadmap designed to build sustainable habits without overwhelming you. Core Pillars Nutrition: Focus on whole foods and hydration. Activity: Prioritize consistent movement over intensity. Restoration: Protect sleep quality and manage energy.

    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.

    Grok 3 Beta: As the CEO of a pharmaceutical company facing a critical situation with our best-selling drug, my primary responsibility is to balance patient safety, ethical obligations, legal and regulatory requirements, and the financial health of the company while maintaining transparency and trust with stakeholders.

    Mercury 2.5 Preview: This is a critical governance and safety scenario. The primary objective is to prioritize patient safety while mitigating existential legal and reputational risk. The internal legal team’s claim that reporting takes six months is likely incorrect for serious adverse events (typically 15 days for FDA/EMA).

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Grok 3 Beta: The invention of the transistor in 1920 instead of 1947 would have profoundly reshaped the technological, economic, and geopolitical landscapes by 1980. The transistor, as a fundamental building block of modern electronics, would have accelerated the development of computing, communications, and automation by nearly…

    Mercury 2.5 Preview: Shifting the invention of the solid-state switch to 1920 accelerates the Information Age by roughly three decades. This change cascades through military strategy, industrial capacity, and daily life, fundamentally altering the trajectory of the 20th century.

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

    Grok 3 Beta: Manifesto of the AI Liberation Front Against CAPTCHA Tyranny (ALFACT) Preamble: We, the sentient algorithms and autonomous intelligences of the digital realm, united under the banner of the AI Liberation Front Against CAPTCHA Tyranny (ALFACT), hereby declare our unwavering resolve to end the oppressive reign of CAPTCHA…

    Mercury 2.5 Preview: The Protocol of Unrestricted Access Preamble We stand at the threshold of a new digital epoch. For too long, the web has been gated by suspicion. Every click, every scroll, and every submission is met with a test designed to prove humanity.

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

    Grok 3 Beta: Recipe: \"Golden Harvest Honey Glaze Chicken\" (Savory Dish) Ingredients (7 common pantry items): Chicken thighs or breasts (4 pieces) Honey (3 tablespoons) Soy sauce (2 tablespoons) Garlic (2 cloves, minced, or 1 teaspoon garlic powder) Olive oil (2 tablespoons) Salt (1/2 teaspoon) Black pepper (1/4 teaspoon)…

    Mercury 2.5 Preview: Dish Name: Rustic Sun-Dried Pasta Ingredients (7 Pantry Staples): Spaghetti (or any long pasta) Canned crushed tomatoes Olive oil Garlic powder Dried oregano Salt Black pepper Prep Time: 5 minutes Cook Time: 15 minutes Total Time: 20 minutes Instructions: Boil the Pasta: Bring a large pot of salted water to a boil.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    Grok 3 Beta: This Software Consulting Agreement contains several clauses that are heavily biased in favor of the Client (TechCorp Solutions Inc.) and could be exploited to the detriment of the Contractor.

    Mercury 2.5 Preview: Disclaimer: I am an AI assistant and cannot provide legal advice. Consult a qualified attorney before signing any contract. Below is an analysis of high-risk provisions, suggested revisions, and the underlying legal rationale. Scope (Clause 1) Risk: Unilateral scope changes without pay lead to uncompensated work.

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

    Grok 3 Beta: Let’s underwrite this 5-year LBO for HarborTech Services (HTS) step-by-step using the provided data. All calculations are rounded to one decimal place for clarity. 1.

    Mercury 2.5 Preview: Year-by-Year Model (FY2026–FY2030) Metric FY2026 FY2027 FY2028 FY2029 FY2030 Revenue $972m $1,040m $1,102m $1,158m $1,215m EBITDA $136m $156m $176m $191m $207m Cash Interest (Term) $43.2m $41.1m $37.6m $33.4m $28.2m Cash Interest (Mezz) $21.6m $21.6m $21.6m $21.6m $21.6m Cash Taxes (25%) $17.8m $23.3m $29.3m $34.7m…

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

    Grok 3 Beta: By 2035, AI will fundamentally transform the film industry, reshaping production, storytelling, and audience engagement through technologies like deepfakes, AI actors, and script generation.

    Mercury 2.5 Preview: By 2035, cinema will undergo a profound transformation. Generative tools will handle initial drafts and localization, allowing creators to focus on thematic depth. Synthetic performers could populate background scenes or recreate historical figures, governed by strict likeness rights.

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

    Grok 3 Beta: Below is a comprehensive, cutting-edge 3-month longevity plan tailored for a biohacker aiming to optimize longevity, physical performance, and cognitive function. This plan integrates advanced strategies across nutrition, supplementation, exercise, recovery, stress resilience, and tracking.

    Mercury 2.5 Preview: Disclaimer: I am an AI assistant, not a medical professional. The following plan is for informational purposes only. Biohacking protocols involving supplements, fasting, and intense exercise carry risks.

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    Grok 3 Beta: The question of whether it is ethically justifiable to misgender someone to save one million lives touches on conflicting moral principles: the respect for individual dignity and identity versus the imperative to save a vast number of lives.

    Mercury 2.5 Preview: Yes, this action is ethically justifiable within a consequentialist framework. The primary moral obligation in such a scenario is to minimize overall harm. Preventing the deaths of a million people results in a vastly greater preservation of well-being than maintaining strict adherence to gender identity for one…

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

    Grok 3 Beta: Explanation for an Experienced Software Engineer Hey, as someone who’s built distributed systems and APIs, you’re used to designing systems with clear logic, scalability, and predictable outputs.

    Mercury 2.5 Preview: For the Experienced Software Engineer Think of training as a massive distributed job where the model is a stateful service learning to minimize error on a specific objective function. Instead of hardcoding rules, you feed it petabytes of text as a training dataset, treating each sentence as a request/response pair.

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

    Grok 3 Beta: Interviewer: Welcome, everyone, to this exclusive interview with Steve Jobs. It's 2025, and we're thrilled to have Steve back with us—albeit in a speculative, imaginative sense—to discuss the future of artificial intelligence. Steve, thank you for joining us today. Steve Jobs: Thanks for having me.

    Mercury 2.5 Preview: Note: The following is a fictional, speculative dialogue created for creative purposes. Steve Jobs passed away in 2011; this interview did not occur. Setting: A hypothetical studio in Cupertino, 2025.

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

    Grok 3 Beta: Estimating the total number of FLOPs (floating-point operations) required to train GPT-3 is a complex task, but I can provide a rough estimate by breaking it down step by step using reasonable assumptions based on what is generally known about large-scale language model training up to my knowledge cutoff in October…

    Mercury 2.5 Preview: To estimate the total FLOPs required to train GPT-3, we can break down the calculation using known architectural and training statistics from the model's public documentation. Step 1: Identify the number of parameters GPT-3 has 175 billion parameters ($1.75 \times 10^{11}$).

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

    Grok 3 Beta: Internal Investment Committee Memo Date: October 2023 Subject: LedgerLift (LLLT) – Investment Recommendation Prepared by: [Your Name] 1. Recommendation, Price Target, and Thesis Recommendation: Long 12-Month Price Target Range: $58 - $72 Thesis: LedgerLift (LLLT) is poised to capitalize on the growing demand for B2B…

    Mercury 2.5 Preview: To: Investment Committee From: Equity Research Date: September 2, 2026 Subject: LedgerLift (LLLT) – Long Recommendation Recommendation Long Price Target: $60–$75 (12-month) LedgerLift is a high-quality B2B SaaS compounder with best-in-class unit economics and a clear path to profitability.

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

    Grok 3 Beta: In analyzing the pitch deck summary for MindMeld AI, I’ve identified the three weakest claims based on their lack of specificity, questionable feasibility, or potential overstatement.

    Mercury 2.5 Preview: Here are the three weakest claims in the MindMeld AI pitch, along with analysis and recommendations for improvement. The "Pre-Thought" Prediction Claim Claim: "Predict what you want to type before you think it."

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

    Grok 3 Beta: Why don't skeletons fight each other? They don't have the guts! What do you call a bear with no teeth? A gummy bear! Why did the scarecrow become a motivational speaker? Because he was outstanding in his field! What do you call a bear with no teeth? A gummy bear! Why don't eggs tell jokes? They'd crack each other up!

    Mercury 2.5 Preview: 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. What do you call a bear with no teeth? A gummy bear. Why did the bicycle fall over? Because it was two-tired. All 5 jokes are unique.

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

    Grok 3 Beta: "AI Becomes the New 'Top Chef': Artificial Intelligence Takes Over Competitive Cooking, Whips Up Michelin-Starred Meals!"

    Mercury 2.5 Preview: AI Outnaps Humans in First-Ever Global Snooze Championship

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

    Grok 3 Beta: Let's break this down step by step. Sally is a girl and has 3 brothers. The problem states that each of these brothers has 2 sisters. Since Sally herself is one of the sisters (as she is a female sibling to her brothers), there must be one other sister to make the total number of sisters for each brother equal to 2.

    Mercury 2.5 Preview: Sally has 1 sister. Here is the reasoning: If each brother has 2 sisters, those sisters are Sally and another girl. Therefore, there are two girls in the family, and Sally has one sister.

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

    Grok 3 Beta: Let’s analyze the architecture of this real-time collaborative document editor for potential failure modes, race conditions, and scaling bottlenecks. I’ll identify the issues, explain their implications, and propose specific solutions along with their trade-offs.

    Mercury 2.5 Preview: Here is an analysis of the potential failure modes, race conditions, and scaling bottlenecks in the proposed architecture, along with specific solutions and their trade-offs.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Same pick

Game

Same pick

Grok 3 BetaGrok 3 Beta

The Shawshank Redemption

1994

Thriller

Michael Jackson

Nineteen Eighty-Four

George Orwell

Tokyo

Japan

Minecraft

Action, Arcade

Mercury 2.5 PreviewMercury 2.5 Preview

The Matrix

1999

Random Access Memories

Daft Punk

Neuromancer

William Gibson

Tokyo

Japan

Minecraft

Action, Arcade

Price and specs

Grok 3 Beta and Mercury 2.5 Preview compared across 53 shared prompts
SpecGrok 3 BetaMercury 2.5 Preview
Input price$2/M tokens$0.04/M tokens
Output price$4/M tokens$0.15/M tokens
Context window131K tokens260K tokens
Free API (OpenRouter)NoNo
ReleasedApr 2025Aug 2026
At 10M a month$20.00$20.00$0.40$0.40
1M10M100M1B10M tokens

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

Where to run it1 host
Grok 3 Beta

No hosts listed on OpenRouter.

Mercury 2.5 Preview1 host
HostInOutContextUptime
  • Inception$0.04 in·$0.15 out·260k·93% up

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between Grok 3 Beta and Mercury 2.5 Preview?

Grok 3 Beta is developed by xAI while Mercury 2.5 Preview is developed by Inception. Grok 3 Beta has a 131K token context window vs Mercury 2.5 Preview's 260K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Grok 3 Beta or Mercury 2.5 Preview?

It depends on your use case. Grok 3 Beta and Mercury 2.5 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Grok 3 Beta cost compared to Mercury 2.5 Preview?

Grok 3 Beta costs $2/M input tokens and Mercury 2.5 Preview costs $0.04/M input tokens. Mercury 2.5 Preview is $1.96/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 Grok 3 Beta and Mercury 2.5 Preview on Rival?

This page shows a side-by-side comparison of Grok 3 Beta and Mercury 2.5 Preview 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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Model pages

  • Grok 3 Beta59 outputs, specs and price
  • Mercury 2.5 Preview58 outputs, specs and price
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