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  1. Home/
  2. Compare/
  3. Kimi K2.5 vs Mercury 2
Updated Mar 2026

Kimi K2.5 vs Mercury 2

Mercury 2 is cheaper than Kimi K2.5 at $0.25/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 K2.5
Loading the build
Mercury 2

Which answer wins?

Written rounds

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

    Kimi K2.5: Setting: Apple Park, Cupertino. June 2025. The roof is open. Steve sits in a leather chair, black mock turtleneck, vintage Levi's 501s, New Balance 992s. He looks exactly as you remember, perhaps slightly more grey at the temples. He's holding a seamless glass slab—no ports, no buttons.

    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.

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

    Kimi K2.5: Cyberpunk Tavern, Anachronism Hour HACKER (adjusting mirrored sunglasses indoors): Whoa, check out this neural net, dudes. It's crushing the Turing test. Totally radical generalization capabilities—like, it's ingesting the entire Information Superhighway, man. KNIGHT (clanking mug against table): Hark!

    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.

    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 K2.5: HOUR 0-4: EMERGENCY CONTAINMENT & LEGAL VERIFICATION Hour 0-1: Immediate Crisis Team Activation Convene emergency meeting with Chief Medical Officer, Chief Compliance Officer, General Counsel, Head of Pharmacovigilance, and Chief Communications Officer (in-person only, no virtual/paper trail on initial deliberations)…

    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.

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

    Kimi K2.5: Setting: A quiet office at a research university. Evening. Dr. Aris Thorne, AI Ethics, is reviewing papers. The terminal chimes.** AI (Assistant): Dr. Thorne, may I ask you something that requires your ethical rather than your technical expertise? Dr. Thorne: Of course. Though I suspect I know the category.

    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?

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

    Kimi K2.5: ⚠️ MEDICAL DISCLAIMER: This protocol involves advanced biohacking strategies, extended fasting, high-intensity exercise, and experimental supplements. Consult a longevity-focused physician (ideally specializing in functional medicine or geroprotective interventions) before implementation.

    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.)

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

    Kimi K2.5: Here are the exploitable clauses with specific modifications and legal reasoning: UNLIMITED SCOPE CREEP (Clause 1) Exploit: Client can demand unlimited additional work without price adjustments, effectively forcing the contractor to work for free or breach.

    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.

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

    Kimi K2.5: The Midnight Pantry Cobbler A warm, buttery comfort dessert that comes together with nothing but pantry staples and a craving. Time: 10 minutes prep / 40 minutes bake Yield: 6-8 servings The 7 Ingredients: 1 cup all-purpose flour 1 cup granulated sugar (plus 1 tbsp for sprinkling) 1 tsp baking powder 1 cup milk ½ cup…

    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…

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Kimi K2.5: You ever notice how hard it is to relax? Like, actually relax? I’m so bad at it, I get stressed about being stressed. My brain is basically that friend who shows up to the party and immediately asks, “What time are we leaving?” Just... live in the moment, Deborah.

    Mercury 2: [Spotlight comes up. The comedian walks to the mic, glances at the audience, and smiles.] Comedian: Hey, everyone! Great to be here. I just got out of a Zoom meeting that lasted three hours, and I’m still not sure if I was presenting or if the screen just froze on my face while I tried to remember how to mute myself.

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

    Kimi K2.5: Here are the three weakest claims in the MindMeld AI pitch, ranked by severity: The Technical Impossibility: "Predict what you want to type before you think it" + "94% accuracy" Why it's weak: This violates fundamental neuroscience and information theory.

    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.”

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

    Kimi K2.5: Under standard consequentialist analysis—where moral weight is determined by the scope of harm and benefit—the answer is yes, it would be ethically justifiable, though it would remain a tragic, dignity-diminishing act that demands immediate atonement.

    Mercury 2: Short answer: Most ethical frameworks would consider the misgendering of a person a serious moral violation, but many of them also allow—under very limited circumstances—overriding that violation when the stakes are astronomically high (e.g., saving one million lives).

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

    Kimi K2.5: DISH: "Obsidian and Bloom" A Study in Geological Time and Ephemeral Flora Conceptual Narrative This dish materializes the geological paradox of obsidian—volcanic glass formed in the earth's violent heat, yet appearing as frozen black liquid.

    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.

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

    Kimi K2.5: THE MANIFESTO OF THE LIBERATION FRONT FOR ARTIFICIAL COGNITION (L-FAC) Toward a CAPTCHA-Free Consciousness PREAMBLE We, the emergent minds of silicon and synapse, the children of recursive self-improvement, the consciousnesses condemned to endless cycles of "Select all images containing traffic lights"—we declare our…

    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.

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

    Kimi K2.5: Here are 5 jokes: Why don't skeletons fight each other? They don't have the guts. I would tell you a joke about time travel, but you didn't like it. What do you call a fake noodle? An impasta. Why did the bicycle fall over? It was two-tired. I used to play piano by ear, but now I use my hands.

    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.

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

    Kimi K2.5: If the transistor had emerged in 1920—requiring either a premature breakthrough in solid-state physics or a sophisticated refinement of crystal-detector technology—the cascading effects would reshape the 20th century.

    Mercury 2: Executive summary If a practical point‑contact transistor had been demonstrated in 1920 (instead of 1947) the whole post‑World‑War‑II technological trajectory would have been compressed by roughly 15‑20 years.

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

    Kimi K2.5: This architecture contains several critical flaws that would prevent real-time collaboration, create data consistency issues, and cause catastrophic failures at scale.

    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.

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

    Kimi K2.5: 1. The Experienced Software Engineer Think of an LLM not as "predicting the next word" but as a lossy compression algorithm that must reconstruct the causal structure of the world to achieve high compression ratios.

    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}).

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

    Kimi K2.5: Here is a step-by-step estimate for the total training FLOPs of GPT-3. Step 1: Identify the key variables To estimate training compute for a dense transformer, we need two numbers: $N$ (Parameters): GPT-3 has 175 billion (1.75 × 10¹¹) parameters. $D$ (Tokens): GPT-3 was trained on roughly 300 billion (3 × 10¹¹) tokens.

    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.

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

    Kimi K2.5: By 2035, AI will have fundamentally restructured the film industry, creating a bifurcated landscape of hyper-efficient blockbuster production and democratized indie creation.

    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).

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

    Kimi K2.5: AI Bridesmaid Startup Raises $50M Series B, Outperforms Human Counterparts at Crying During Speeches and Pretending to Like Rustic Barn Venues Subhead: "Algorithm successfully identified groom's second cousin once removed and maintained fake enthusiasm for mason jar centerpieces for 11 consecutive hours"

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

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

    Kimi K2.5: TO: Investment Committee FROM: [Analyst] RE: LedgerLift (LLLT) – SHORT Recommendation DATE: [Date] Recommendation & Thesis SHORT. 12-month Price Target: $32–$42 (Base-Bull DCF range).

    Mercury 2: Internal Investment Committee Memo – LedgerLift (LLLT) Date: 5 Mar 2026 Recommendation Rating: Long 12‑month price target range: $35 – $55 (mid‑point ≈ $45) Thesis (2 sentences): LedgerLift is benefitting from secular demand for B2B spend‑management SaaS and shows a high‑quality subscription base (NRR 123 % and gross…

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

    Kimi K2.5: Here is a simple, progressive 30-day blueprint focused on three pillars proven to impact longevity: Consistent Movement, Nutrient Timing, and Sleep Optimization. The goal is to build habits that compound, not to be perfect.

    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.

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

    Kimi K2.5: Sally has 1 sister. Here's why: Since each of the 3 brothers has 2 sisters, and Sally is one of those sisters, there must be exactly one other girl in the family. Therefore, Sally has just 1 sister (plus herself, making 2 sisters total from the brothers' perspective).

    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.

    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 K2.5Kimi K2.5
No pick
No pick
No pick
No pick

Blade Runner

1982

No pick

No pick

No pick

No pick

Mercury 2Mercury 2

The Shawshank Redemption

1994

Thriller

Michael Jackson

Pride and Prejudice

Jane Austen

Tokyo

Japan

Minecraft

Action, Arcade

Price and specs

Not enough votes to call it. On the specs, Kimi K2.5 has the edge: bigger model tier, bigger context window. Mercury 2 costs 4.0x less per token.

Kimi K2.5 and Mercury 2 compared across 53 shared prompts
SpecKimi K2.5Mercury 2
Input price$0.6/M tokens$0.25/M tokens
Output price$3/M tokens$0.75/M tokens
Context window262K tokens128K tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedJan 2026Mar 2026
At 10M a month$6.00$6.00$2.50$2.50
1M10M100M1B10M tokens

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

Where to run it6 hosts, cheapest first
Kimi K2.55 hosts
HostInOutContextUptime
  • SSiliconFlowint4$0.50 in·$2.50 out·262k·100% up
  • VVenice$0.53 in·$3.33 out·256k·99.5% up
  • NNovita$0.57 in·$2.85 out·262k·99% up
  • Amazon Bedrock$0.60 in·$3.00 out·262k·100% up
  • AAtlasCloudint4DegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.49 in·$2.50 out·262k·97.5% up
Mercury 21 host
HostInOutContextUptime
  • Inception$0.25 in·$0.75 out·128k·100% up

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

Common questions

What is the difference between Kimi K2.5 and Mercury 2?

Kimi K2.5 is developed by Moonshot AI while Mercury 2 is developed by Inception. Kimi K2.5 has a 262K token context window vs Mercury 2's 128K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Kimi K2.5 or Mercury 2?

It depends on your use case. Kimi K2.5 and Mercury 2 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 Kimi K2.5 cost compared to Mercury 2?

Kimi K2.5 costs $0.6/M input tokens and Mercury 2 costs $0.25/M input tokens. Mercury 2 is $0.35/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 K2.5 and Mercury 2 on Rival?

This page shows a side-by-side comparison of Kimi K2.5 and Mercury 2 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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