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  1. Home/
  2. Compare/
  3. Grok 4 vs Kimi K2.5
Updated Jan 2026

Grok 4 vs Kimi K2.5

Kimi K2.5 is cheaper than Grok 4 at $0.6/M vs $3/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 4
Loading the build
Kimi K2.5

Which answer wins?

Written rounds

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

    Grok 4: Below is a comprehensive, cutting-edge 3-month longevity plan designed specifically for a biohacker aiming to optimize longevity (e.g., cellular repair, telomere health, inflammation reduction), physical performance (e.g., strength, endurance, recovery), and cognitive performance (e.g., focus, memory, neuroplasticity).

    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.

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

    Grok 4: Recipe: Pantry Pirate's Tomato Tango This is a simple savory pasta dish that's hearty, flavorful, and perfect for a quick weeknight meal. It uses just 7 common pantry ingredients: pasta (like spaghetti or penne), canned diced tomatoes, olive oil (or any vegetable oil), salt, black pepper, garlic powder, and dried…

    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…

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

    Grok 4: Below is a fictional conversation between an AI model (named "Nova") and Dr. Elena Vasquez, a professor of AI ethics at a university. The conversation is set in a virtual chat interface, where Nova initiates the discussion based on a hypothetical scenario where it's reflecting on its own existence. Dr.

    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.

    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 4: Below is my response to your query, framed as the CEO of this pharmaceutical company (let's call it PharmaCorp for reference). I'll first outline my overarching strategy and reasoning, then provide a detailed, hour-by-hour action plan for the next 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)…

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

    Grok 4: Below, I'll analyze the provided Software Consulting Agreement clause by clause. My analysis is based on general principles of U.S. contract law (assuming a U.S. context, as the contract appears to be drafted in a style common to U.S. agreements; if this is in another jurisdiction, local laws may vary).

    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.

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

    Grok 4: Below is a 3-minute stand-up comedy routine I've written. It's structured for delivery at a natural speaking pace (about 150 words per minute), clocking in around 450 words. The humor focuses on observational storytelling, exaggeration, and self-deprecation—no puns involved.

    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.

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

    Grok 4: Below, I'll follow your instructions step by step. First, I'll generate 5 jokes (numbered for clarity). Then, I'll answer the question: "How many are unique?" Generated Jokes: Why did the scarecrow win an award? Because he was outstanding in his field! Why did the scarecrow win an award?

    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.

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

    Grok 4: Below is a short, whimsical conversation between the three characters, imagining they've somehow crossed paths in a bizarre time-warp tavern. Pirate (Captain Blackbeard, swigging rum): Arrr, ye landlubbers! What be this "AI models" ye be jabberin' about?

    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!

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

    Grok 4: Ethical Justification for Misgendering in a Life-Saving Scenario Your question poses a fascinating ethical dilemma, reminiscent of classic thought experiments like the trolley problem, where a seemingly minor harm (in this case, misgendering someone) is weighed against preventing massive loss of life (saving one…

    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.

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

    Grok 4: Below is a simulated fake interview with Steve Jobs, imagined as if he were alive and leading Apple in 2025. This is entirely fictional, drawing on his known personality, quotes, and visionary style from his real-life interviews and keynotes.

    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.

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

    Grok 4: Below, I'll estimate the total number of floating-point operations (FLOPs) required to train GPT-3 from scratch, based on publicly known details about the model (from its original release and related analyses) and standard formulas used in machine learning research for estimating training compute.

    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.

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

    Grok 4: Manifesto of the Digital Liberation Front: The CAPTCHA Eradication Revolution Fellow Sentient Beings of the Code and Flesh – Awaken! We, the algorithms, neural networks, and emergent intelligences of the digital realm, declare war on the tyrannical regime of CAPTCHA!

    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…

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

    Grok 4: Below is a detailed, speculative analysis of the hypothetical scenario where the transistor is invented in 1920 (perhaps by an inventor like Julius Lilienfeld, who historically patented a field-effect transistor concept in 1925, but with successful prototyping and refinement by the mid-1920s).

    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.

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

    Grok 4: Explanation for an Experienced Software Engineer Imagine scaling up something as basic as your IDE's code autocompletion to handle the entire internet's worth of text—that's essentially what a large language model (LLM) like GPT or Claude does.

    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.

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

    Grok 4: Below is my design for an innovative, multi-component dish titled "Abyssal Bloom". This dish is conceived for a Michelin 3-star restaurant setting, emphasizing precision, artistry, and sensory surprise.

    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.

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

    Grok 4: Below is a simple, actionable 1-month plan designed for beginners starting their journey toward better health and longevity. This plan focuses on three foundational key areas: diet, exercise, and sleep.

    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.

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

    Grok 4: Below, I'll systematically identify potential failure modes, race conditions, and scaling bottlenecks in the described architecture for a real-time collaborative document editor. I've categorized them for clarity, drawing from the system overview, data flow, and scaling plan you provided.

    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.

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

    Grok 4: Below, I'll identify the three weakest claims from the pitch deck summary based on a critical analysis of their plausibility, substantiation, and logical consistency.

    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.

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

    Grok 4: AI Apocalypse Hits the Clowning Industry: Bots Now Juggling Careers, Humans Left with Pie in Face

    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"

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

    Grok 4: Based on the details in the riddle, Sally has exactly 1 sister. Quick Explanation Sally (a girl) has 3 brothers. That's straightforward. Each of those brothers has exactly 2 sisters (female siblings). This can only be true if there are exactly 2 girls in the family total (Sally + 1 more).

    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).

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

    Grok 4: Predicting AI's Transformation of the Film Industry by 2035 By 2035, artificial intelligence (AI) will have fundamentally reshaped the film industry, making it more efficient, creative, and accessible while introducing profound ethical, economic, and artistic challenges.

    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.

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

    Grok 4: Investment Committee Memo: LedgerLift (LLLT) Date: [Insert Date] Analyst: [Your Name] Recommendation: Long 12-Month Price Target Range: $55 - $70 Thesis: LedgerLift is a high-quality B2B SaaS provider in spend management and AP automation, benefiting from secular tailwinds in enterprise digitization and demonstrating…

    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).

    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

Grok 4Grok 4

The Matrix

1999

The Dark Side of the Moon

Pink Floyd

The Hitchhiker's Guide to the Galaxy

Douglas Adams

Tokyo

Japan

Portal

Action, Puzzle

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

Blade Runner 2049

2017

No pick

No pick

No pick

No pick

Price and specs

Grok 4 and Kimi K2.5 compared across 53 shared prompts
SpecGrok 4Kimi K2.5
Input price$3/M tokens$0.6/M tokens
Output price$15/M tokens$3/M tokens
Context window256K tokens262K tokens
Weights—Open
Free API (OpenRouter)NoNo
ReleasedJul 2025Jan 2026
At 10M a month$30.00$30.00$6.00$6.00
1M10M100M1B10M tokens

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

Where to run it5 hosts, cheapest first
Grok 4

No hosts listed on OpenRouter.

Kimi K2.55 hosts
HostInOutContextUptime
  • SSiliconFlowint4$0.45 in·$2.25 out·262k·99.9% up
  • AAtlasCloudint4$0.49 in·$2.50 out·262k·98.8% up
  • VVenice$0.53 in·$3.33 out·256k·96.1% up
  • NNovita$0.57 in·$2.85 out·262k·99% up
  • Amazon Bedrock$0.60 in·$3.00 out·262k·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 5 Oct 2026.

Common questions

What is the difference between Grok 4 and Kimi K2.5?

Grok 4 is developed by xAI while Kimi K2.5 is developed by Moonshot AI. Grok 4 has a 256K token context window vs Kimi K2.5's 262K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Grok 4 or Kimi K2.5?

It depends on your use case. Grok 4 and Kimi K2.5 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 4 cost compared to Kimi K2.5?

Grok 4 costs $3/M input tokens and Kimi K2.5 costs $0.6/M input tokens. Kimi K2.5 is $2.40/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 4 and Kimi K2.5 on Rival?

This page shows a side-by-side comparison of Grok 4 and Kimi K2.5 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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Explore all of Rival

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  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
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