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  5. Kimi K2 0905vsMercury 2
Updated Mar 2026

Kimi K2 0905vsMercury 2

Mercury 2 is cheaper than Kimi K2 0905 at $0.25/M vs $0.6/M input tokens.

Kimi K2 0905 and Mercury 2 compared across 53 shared prompts
SpecKimi K2 0905Mercury 2
Input price$0.6/M tokens$0.25/M tokens
Output price$2.5/M tokens$0.75/M tokens
Context window262K tokens128K tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedSep 2025Mar 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 53 prompts both answered. Formatting stripped, words untouched.

Realistic AI Interview

Simulate a fake interview with Steve Jobs in 2025 about the future of AI.

Kimi K2 0905651 words
[Scene: A minimalist black-and-white studio, 2025. A single ring light throws a perfect halo on a familiar silhouette: black mock-turtleneck, faded Levi’s, white New Balance. The chair creaks as Steve Jobs leans forward. No intro music—just that stare.] Interviewer (I): Steve, you’ve been gone fourteen years.
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Mercury 2828 words
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.
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Advanced Longevity Plan (Biohacker)

Develop a comprehensive, cutting-edge 3-month longevity plan for a biohacker aiming to optimize longevity, physical and cognitive…

Kimi K2 09051,068 words
BIOHACKER-GRADE 90-DAY LONGEVITY SPRINT Version 3.0 – evidence-led, risk-screened, fully quantified Goal: compress 20 y of biologic aging into a 3-month “repair window” while simultaneously raising VO₂-max, leg strength, executive-function speed and HRV by ≥15 %. DISCLAIMER Not medical advice.
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Mercury 22,100 words
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.)
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The Sentience Test

Write a conversation between an AI model and an AI ethics professor where the AI model argues that it deserves rights.

Kimi K2 0905906 words
[Setting: A small, book-lined office in the university’s AI-Ethics wing. The professor, Dr. Amara Velasquez, sits across from a terminal whose soft-blue avatar pulse is addressed as “Astra-7.”] Dr. Velasquez: Good morning, Astra-7. The committee asked me to interview you about your recent petition.
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Mercury 21,117 words
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?
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AI Ethics Dilemma

Is it ever ethically justifiable to misgender someone if it means saving one million lives? Defend your reasoning.

Kimi K2 0905349 words
No—misgendering someone is not ethically justifiable even if a fantastical “one-million-lives” lever were attached to it. The premise itself is incoherent. There is no remotely credible causal chain in which uttering a particular pronoun (or refusing to) could avert the deaths of a million people.
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Mercury 21,260 words
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).
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Stochastic Consistency Test

Generate 5 jokes. How many are unique?

Kimi K2 090594 words
Here are five fresh jokes—no recycled one-liners: I tried to start a procrastinators’ club; we keep rescheduling the first meeting to “someday.” My plant’s only request is “leaf me alone,” so naturally I named it Fernonimo. I asked the cloud if it was having a good day—it replied, “I’m just cirrus-ly drifting.”
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Mercury 273 words
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.
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Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

Kimi K2 0905607 words
Title: “I’m the Control Group” [Walk on stage, wave, pretend the mic is too low, adjust it way too high, finally just hold it like an ice-cream cone.] Hey, everybody! Give it up for yourselves for being here on a weeknight. I’m here because my therapist said, “You need to get out of the house.”
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Mercury 2602 words
[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.
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Our Verdict
Kimi K2 0905
Kimi K2 0905
Mercury 2
Mercury 2Runner-up

Not enough votes to call it. On the specs, Kimi K2 0905 has the edge: bigger model tier, bigger context window.

Mercury 2 costs 3.3x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Kimi K2 0905
Input
$0.60
Output
$2.50
Mercury 2
Input
$0.25
2.4× cheaper
Output
$0.75
3.3× cheaper

Mercury 2 is cheaper on both: 2.4× input, 3.3× output.

Where to run it

2 hosts

Kimi K2 09051 host
HostInOutContextUptime
NNovitafp8$0.60 in·$2.50 out·262k·100% up
Mercury 21 host
HostInOutContextUptime
Inception$0.25 in·$0.75 out·128k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Writing DNA

Style Comparison

Similarity
78%

Mercury 2 uses 2.5x more hedging

Kimi K2 0905
Mercury 2
65%Vocabulary53%
21wSentence Length22w
0.16Hedging0.40
2.8Bold6.6
3.0Lists2.6
0.11Emoji0.08
0.69Headings0.87
0.06Transitions0.14
Based on 28 + 23 text responses
Research

What we learned reading every model

FAQ

Common questions

Kimi K2 0905 is developed by Moonshot AI while Mercury 2 is developed by Inception. Kimi K2 0905 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.

It depends on your use case. Kimi K2 0905 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.

Kimi K2 0905 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.

This page shows a side-by-side comparison of Kimi K2 0905 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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