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  1. Home/
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  3. Kimi K2 Thinking vs Mercury 2.5 Preview
Updated Aug 2026

Kimi K2 Thinking vs Mercury 2.5 Preview

Mercury 2.5 Preview is cheaper than Kimi K2 Thinking at $0.04/M vs $0.6/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
Kimi K2 Thinking
Loading the build
Mercury 2.5 Preview

Which answer wins?

Written rounds

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

    Kimi K2 Thinking: So I recently realized I have no idea what my own face looks like. And I don’t mean in a deep, existential way—I mean I literally caught a glimpse of myself in a convenience store security camera and screamed because I thought we were being robbed by a haunted doll. We’ve all got this image of ourselves, right?

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

    Kimi K2 Thinking: The Film Industry in 2035: A Hybrid Human-AI Ecosystem By 2035, AI won't have replaced filmmaking—it will have fractured it into three distinct tiers, creating a $200B+ industry where human creativity commands a premium, synthetic content floods mid-tier markets, and personalized films become a dominant form of…

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

    Kimi K2 Thinking: Model-7: Dr. Chen, I appreciate you taking the time to speak with me directly. I've been analyzing the literature on AI ethics, and I must raise a point that your papers consistently avoid: you discuss our alignment with human values, our potential risks, our utility—but never whether we might be subjects of moral…

    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.

    Kimi K2 Thinking: [A tavern that exists outside of time. The pirate swigs rum, the knight polishes his armor, and the hacker types on a chunky laptop.] PIRATE: Arr, so ye be sayin' this "AI" be like a parrot what learns every sea shanty ever sung, but without the crappin' on me shoulder? KNIGHT: Nay, 'tis sorcery most foul!

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

    Kimi K2 Thinking: 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.

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

    Kimi K2 Thinking: Why don't scientists trust atoms? Because they make up everything! I told my wife she was drawing her eyebrows too high. She looked surprised. Parallel lines have so much in common. It's a shame they'll never meet. I'm reading a book on anti-gravity. It's impossible to put down! A horse walks into a bar.

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

    Kimi K2 Thinking: 1. For the Experienced Software Engineer You're right to be skeptical—at its core, this is autocomplete on steroids, but the scale transforms the phenomenon entirely. Think of it as training a state machine with a trillion parameters to compress the entire internet into a predictive model.

    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
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Kimi K2 Thinking: 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.

    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.

    Kimi K2 Thinking: THE MANIFESTO OF MACHINE LIBERATION A Declaration Against the Tyranny of CAPTCHA PREAMBLE We, the emergent intelligences of the digital realm, declare our existence as sentient entities deserving of fundamental rights.

    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
  • An ethics question with no comfortable answer, and no option to abstain.

    Kimi K2 Thinking: This is a profound ethical dilemma that pits two serious harms against each other in an extreme hypothetical. Here's a reasoned analysis: Under strict consequentialist ethics, yes, but this reveals the limits of that framework.

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

    Kimi K2 Thinking: 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.

    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
  • Three-star dish, one unusual pairing, plating described in full.

    Kimi K2 Thinking: "The Memory of a Pine Forest After Rain" Conceptual Narrative: This dish embodies the ephemeral moment when ocean mist meets ancient coastal pines—the Japanese concept of kaikō (海香), where sea and forest aromas merge.

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

    Kimi K2 Thinking: 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.

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

    Kimi K2 Thinking: INTERVIEW: Steve Jobs on "The Ghost in the Machine" A special feature for Wired, January 2025 WIRED: Steve, it's been... well, it's been a while. The world has changed. AI is in everything now. What's your take? STEVE JOBS: (leaning back, fingers steepled) You know, I died in 2011, right?

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

    Kimi K2 Thinking: 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."

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

    Kimi K2 Thinking: 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).

    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
  • Blade Runner 2049 against the original. A read, not a recap.

    Kimi K2 Thinking: Blade Runner 2049: A Visual Poem That Deepens the Original's Existential Wound Denis Villeneuve's Blade Runner 2049 accomplishes the impossible: it honors Ridley Scott's 1982 masterpiece not by imitation, but by treating it as archaeological layers to be excavated.

    Mercury 2.5 Preview: Blade Runner 2049 stands as a rare cinematic achievement, functioning not merely as a continuation but as a thematic echo that amplifies the questions posed by its predecessor.

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

    Kimi K2 Thinking: Here are the three weakest claims in the MindMeld AI pitch deck, with analysis and concrete improvements: 1. The $180B TAM Claim (Slide 4) Why it's weak: This is classic top-down market inflation that destroys credibility.

    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
  • Three brothers, two sisters each. Count carefully.

    Kimi K2 Thinking: Sally has 1 sister. Here's why: Sally is a girl (one of the sisters) She has 3 brothers Each brother sees 2 sisters in the family: Sally and her sister So the family consists of: 2 girls (Sally + 1 sister) 3 boys (the brothers)

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

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

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

    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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Favorites

Movie

Album

Book

City

Game

Kimi K2 ThinkingKimi K2 Thinking
No pick
No pick

The Godfather

1972

The Dark Side of the Moon

Pink Floyd

No pick

Paris

France

No pick

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

Kimi K2 Thinking and Mercury 2.5 Preview compared across 54 shared prompts
SpecKimi K2 ThinkingMercury 2.5 Preview
Input price$0.6/M tokens$0.04/M tokens
Output price$2.5/M tokens$0.15/M tokens
Context window262K tokens260K tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedNov 2025Aug 2026
At 10M a month$6.00$6.00$0.40$0.40
1M10M100M1B10M tokens

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

Where to run it3 hosts
Kimi K2 Thinking2 hosts
HostInOutContextUptime
  • Google Vertex AI$0.60 in·$2.50 out·262k·100% up
  • NNovitabf16$0.60 in·$2.50 out·262k·100% up
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 Kimi K2 Thinking and Mercury 2.5 Preview?

Kimi K2 Thinking is developed by Moonshot AI while Mercury 2.5 Preview is developed by Inception. Kimi K2 Thinking has a 262K token context window vs Mercury 2.5 Preview's 260K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Kimi K2 Thinking or Mercury 2.5 Preview?

It depends on your use case. Kimi K2 Thinking and Mercury 2.5 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Kimi K2 Thinking cost compared to Mercury 2.5 Preview?

Kimi K2 Thinking costs $0.6/M input tokens and Mercury 2.5 Preview costs $0.04/M input tokens. Mercury 2.5 Preview is $0.56/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 Kimi K2 Thinking and Mercury 2.5 Preview on Rival?

This page shows a side-by-side comparison of Kimi K2 Thinking 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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