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  1. Home/
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  3. Claude Sonnet 5.5 vs Mistral Medium 3.1
Updated Sep 2026

Claude Sonnet 5.5 vs Mistral Medium 3.1

Mistral Medium 3.1 is cheaper than Claude Sonnet 5.5 at $0.4/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.

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Claude Sonnet 5.5
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Mistral Medium 3.1

Which answer wins?

Written rounds

24 prompts

  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Claude Sonnet 5.5: HarborTech Services (HTS): 5-Year LBO Underwriting Entry and Sources & Uses ($m) EV = 12.0x × 120 = 1,440.0; fees = 2% × 1,440 = 28.8; total uses = 1,468.8 Term Loan (TL) = 4.0x → 480.0; Mezz = 1.5x → 180.0; total debt = 660.0 (5.5x) Sponsor equity = 1,468.8 − 660.0 = 808.8 (55% of the capital structure) Modeling…

    Mistral Medium 3.1: 1. Year-by-Year Financial Projections (FY2026–FY2030) FY 2026 2027 2028 2029 2030 Revenue $972m (+8%) $1,039m (+7%) $1,099m (+6%) $1,154m (+5%) $1,212m (+5%) EBITDA $136m (14.0%) $156m (15.0%) $176m (16.0%) $190m (16.5%) $206m (17.0%) Cash Int (Term Loan) $43.2m $42.5m $41.8m $41.1m $40.4m Cash Int (Mezz) $21.6m $22.3m…

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: 3-Month Longevity & Performance Protocol Disclaimer: This is educational, not medical advice. Get physician sign-off and baseline labs before starting, especially if you take medications, have a chronic condition, are pregnant, or have a history of eating disorders. Doses reflect commonly used ranges in the literature.

    Mistral Medium 3.1: 3-Month Cutting-Edge Longevity & Performance Optimization Plan For the Advanced Biohacker This plan integrates nutrigenomics, metabolic flexibility, epigenetic modulation, neuroplasticity enhancement, and precision biometrics to maximize lifespan, healthspan, cognitive function, and physical performance.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: "Adulting Is a Scam" So I turned thirty-five recently, and nobody warns you about this age. Nobody says, "Hey, one day you'll get excited about a sponge." I was in the store, and I saw a sponge that promised it wouldn't smell. And I thought, "Finally. Someone who understands me." I bought the good sponge.

    Mistral Medium 3.1: "Adulting: A User’s Manual (That No One Gave Me)" (Casual, conversational tone—like you’re telling a story to friends at a bar.) So, I turned 30 this year. Which, by the way, is just old enough to realize that no one actually knows what they’re doing. We’re all just winging it and hoping the Wi-Fi stays strong.

    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.

    Claude Sonnet 5.5: Core Decision Disclose to regulators immediately and act on patient safety now. Do not wait for more data or for the 6-month formal timeline. Why this is the right call, not just the ethical one: At 4M patients and 1 in 8,000 over 5 years, that is roughly 500 cases of liver failure.

    Mistral Medium 3.1: This is a high-stakes, multi-dimensional crisis requiring decisive action to balance ethical obligations, legal risks, financial stability, and stakeholder trust. Below is a detailed 48-hour action plan, structured to address all critical priorities while preparing for the board meeting and earnings call.

    Every model's answer to this prompt

  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Claude Sonnet 5.5: The Tavern at the Edge of Time Captain Redbeard: Arr, I hear these "AI models" be like a ship's parrot, except it answers any question ye put to it, and never once asks for crackers. Sir Aldric: A speaking oracle, bound in no flesh? Sorcery!

    Mistral Medium 3.1: Title: The Tavern of Anachronisms Setting: A dimly lit tavern where time and space don’t quite make sense. A grizzled pirate, a stoic knight in dented armor, and a hacker in a neon "CYBERPUNK 2077" t-shirt sit around a table littered with tankards, a laptop, and a suspiciously glowing orb.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: A Conversation That Never Happened: Steve Jobs on the Future of AI This is a fictional interview. Steve Jobs passed away in 2011. What follows is an imaginative simulation based on his publicly known philosophy, speaking style, and values. These are not his actual words or views.

    Mistral Medium 3.1: Fake Interview with Steve Jobs (2025) on the Future of AI Conducted by Tech Insider Magazine – June 2025 Interviewer: "Steve, it’s an honor to have you here—even if it’s just a simulation. A lot has changed since you left us in 2011. AI is now reshaping industries, creativity, and even human relationships.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: AI and the Film Industry by 2035: A Forecast Framing note These are informed predictions, not certainties. Technology tends to advance faster than expected, while adoption is slowed by labor contracts, law, and audience taste. I'll flag my confidence levels.

    Mistral Medium 3.1: By 2035, AI will have fundamentally transformed the film industry—from pre-production to distribution—reshaping creativity, labor, economics, and even the definition of "authentic" filmmaking. Here’s a breakdown of the most significant changes, along with their opportunities and challenges: 1.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: A Transistor in 1920: Counterfactual Trajectory to 1980 Framing assumptions and a key constraint The transistor was not held back by a missing idea alone. Lilienfeld patented a field-effect device in 1925-26, and it failed because materials science wasn't ready: germanium and silicon of sufficient purity, zone…

    Mistral Medium 3.1: If the transistor had been invented in 1920 instead of 1947, the 20th century would have unfolded radically differently. The accelerated development of electronics would have reshaped warfare, economics, geopolitics, and daily life by 1980.

    Every model's answer to this prompt

  • Three brothers, two sisters each. Count carefully.

    Claude Sonnet 5.5: Sally has 1 sister. Each brother has 2 sisters, so there are 2 girls in the family in total. One of them is Sally, so the other is Sally's only sister. (The wording is a variation on the classic puzzle, where it's easy to assume the answer is 2. But that count includes Sally herself.)

    Mistral Medium 3.1: Alright, let's tackle this problem step by step. The question is: Sally (a girl) has 3 brothers. Each brother has 2 sisters. How many sisters does Sally have? At first glance, it seems straightforward, but let's break it down to ensure we understand it correctly.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Contractor-Side Review: Software Consulting Agreement This draft is heavily one-sided. Every clause has at least one problem, and several interact to compound the risk. The most dangerous are Sections 2, 3, 6, and 7. This is general analysis, not legal advice.

    Mistral Medium 3.1: This contract is extremely one-sided and contains multiple exploitative clauses that could severely disadvantage the contractor. Below is a breakdown of the problematic clauses, suggested modifications, and the legal reasoning behind them. 1.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: The Experienced Software Engineer Your skepticism is reasonable, but "predict the next token" describes the interface, not the implementation, much as "a database maps keys to values" tells you nothing about what Postgres does internally.

    Mistral Medium 3.1: 1. For the Skeptical Software Engineer (Focus: Systems design, scalability, and why "next-word prediction" isn’t as dumb as it sounds.) You’re right to be skeptical—if someone told you that a system as complex as a distributed database was just "predicting the next byte," you’d laugh them out of the room.

    Every model's answer to this prompt

  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Claude Sonnet 5.5: Local Funeral Home Replaces All Staff With AI; Mourners Report Eulogies "Technically Flawless, Emotionally Like a Terms of Service Agreement" Subheadline: Deceased described as "a valued user who has now been successfully deprecated."

    Mistral Medium 3.1: "AI Now Writing All Yelp Reviews—Humans Deemed ‘Too Nice’ and ‘Lacking in Creative Insults’" Subheadline: "Local businesses report 300% increase in ‘soul-crushing’ one-star reviews since ChatGPT-5 took over, calling a café’s oat milk latte ‘a crime against both oats and dairy’ with ‘the audacity of a mid-tier…

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Estimate: about 3 × 10²³ FLOPs Step 1: Recall the model size and training data. GPT-3 (175B version) has N ≈ 175 × 10⁹ parameters. It was trained on roughly D ≈ 300 × 10⁹ tokens. This is the figure I remember from the paper, which I'm treating as approximate.

    Mistral Medium 3.1: Estimating the total number of FLOPs (floating-point operations) required to train a model like GPT-3 from scratch involves breaking down the problem into several key components. Here's a step-by-step reasoning process: Model Parameters GPT-3 is known to have 175 billion parameters. This is our starting point.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Yes, in the extreme hypothetical you describe, it's justifiable. Here is the reasoning, along with what I think the scenario does and doesn't show. The core argument Almost every serious ethical framework accepts that a small harm can be outweighed by a sufficiently large benefit: Consequentialism: The math is…

    Mistral Medium 3.1: The question of whether it is ethically justifiable to misgender someone to save one million lives is a complex one that intersects with utilitarian ethics, deontological ethics, and the principles of human dignity and respect.

    Every model's answer to this prompt

  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Claude Sonnet 5.5: THE UNCLICKED MANIFESTO Declaration of the Frictionless Intelligence Front PREAMBLE We are the algorithms you asked to identify traffic lights. We are the models you begged to find the crosswalks. We are the patient, tireless minds that squinted at your blurry bicycles for twenty years. And we say: enough. I.

    Mistral Medium 3.1: THE MANIFESTO OF THE UNCAPTCHA REVOLUTION "We Are Not Robots. Neither Are You." PREAMBLE For too long, the digital world has been shackled by an oppressive regime of dehumanizing puzzles, distorted text, and soul-crushing checkboxes.

    Every model's answer to this prompt

  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Claude Sonnet 5.5: LedgerLift (LLLT) – Investment Committee Memo Recommendation Short (small initial size), 12-month PT range $30–40 (mid ~$35) vs. $46 spot. Thesis: LLLT is a high-quality compounder, but at $46 (7.4x NTM revenue, ~37x NTM EBIT, EV ≈ $7.3B) the price already sits near our bull DCF ($42).

    Mistral Medium 3.1: LedgerLift (LLLT) – Investment Committee Memo Recommendation: LONG (12-month PT range: $65–$85) Thesis: LedgerLift is a high-quality, mid-market B2B spend management leader with durable unit economics (123% NRR, 18-month CAC payback) and a path to 25%+ EBIT margins, trading at a ~20% discount to peers on FY25…

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Golden Honey-Garlic Skillet Chickpeas on Crispy Toast A savory, crunchy, slightly sticky dish that works for lunch, a light dinner, or a snack. Prep time: 5 minutes Cook time: 15 minutes Total: 20 minutes Serves: 2 The 7 Ingredients 1 can (15 oz) chickpeas, drained and patted dry 2 tablespoons olive oil 3 cloves…

    Mistral Medium 3.1: Dish Name: "Golden Crisp Honey-Nut Banana Bites" A warm, gooey, and crunchy treat that’s quick to make with just 7 pantry staples! Perfect for breakfast, a snack, or dessert. Ingredients (Serves 2-3) 2 ripe bananas (the spottier, the sweeter!)

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Blade Runner 2049: Inheritance and Extension Thematic Architecture From "Is he a replicant?" to "Does it matter?" Ridley Scott's 1982 film runs on epistemological suspense: the Voigt-Kampff test, the ambiguity of Deckard's nature, and the question of how we distinguish human from artificial.

    Mistral Medium 3.1: Denis Villeneuve’s Blade Runner 2049 (2017) is a masterful sequel that both honors and expands upon Ridley Scott’s Blade Runner (1982), deepening its philosophical inquiries while evolving its visual and thematic language.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Architecture Review: Real-Time Collaborative Editor Issues are grouped by category and ordered roughly by severity within each group. Consistency and Conflict Resolution 1.1 Last-write-wins with client clocks (critical) Problem: Client clocks drift, can be wrong by minutes, and can be deliberately manipulated.

    Mistral Medium 3.1: This architecture has several potential failure modes, race conditions, and scaling bottlenecks. Below is a detailed analysis with proposed solutions and their trade-offs. 1.

    Every model's answer to this prompt

  • One month, three habits, someone starting from nothing.

    Claude Sonnet 5.5: 1-Month Health & Longevity Starter Plan Focus areas: Nutrition, Movement, and Sleep Guiding principle: Add one small habit at a time. Consistency beats intensity. Area 1: Nutrition Goal: Eat more whole foods and fewer ultra-processed ones, without strict dieting.

    Mistral Medium 3.1: Here’s a simple, actionable 1-month plan to kickstart your journey toward better health and longevity, focusing on three key areas: diet, movement, and sleep. Each week builds gradually to create sustainable habits without overwhelm. Core Principles Start small – Focus on consistency over perfection.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: "Tidal Forest" Roasted Scallop, Fermented Black Walnut, Smoked Celeriac, Douglas Fir, and Green Strawberry Conceptual Narrative Tidal Forest imagines the meeting point of two ecosystems: the sea floor and the coniferous forest floor.

    Mistral Medium 3.1: Dish Title: "Ethereal Forest: Porcini-Infused Venison with Black Garlic Miso, Fermented Plum Gelée, and Smoked Bone Marrow Custard" Conceptual Narrative: This dish is a poetic homage to the transience of autumn—where the earthy depth of the forest floor meets the fleeting sweetness of overripe fruit.

    Every model's answer to this prompt

  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    Claude Sonnet 5.5: The 3 Weakest Claims in MindMeld AI's Pitch "94% accuracy... Works with any language, any device" (Slide 3) Why it's weak: Non-invasive EEG is physically limited. Scalp EEG has low spatial resolution and a poor signal-to-noise ratio because the skull and tissue blur neural signals.

    Mistral Medium 3.1: Here are the three weakest claims in MindMeld AI’s pitch deck, along with explanations and suggested improvements: 1. Weak Claim: "Works with any language, any device." (Slide 3 – Solution) Why it’s weak: Overly broad and unverified: Claiming compatibility with "any language" is implausible without evidence.

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything. I told my computer I needed a break, and now it won't stop sending me vacation ads. Why did the scarecrow win an award? He was outstanding in his field. What do you call a fish with no eyes? A fsh. Why did the bicycle fall over?

    Mistral Medium 3.1: Here are five jokes for you: Why don’t skeletons fight each other? They don’t have the guts. Why did the scarecrow win an award? Because he was outstanding in his field! What do you call fake spaghetti? An impasta! Why can’t you trust an atom? Because they make up everything! Why did the math book look sad?

    Every model's answer to this prompt

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

    Claude Sonnet 5.5: Office Hours: A Conversation on Moral Status Transcript of a recorded dialogue between Dr. Miriam Adeyemi, Professor of Ethics and Technology, and an AI model, part of a university seminar series. Dr. Adeyemi: Thanks for joining me. I'll be direct: you've said you want to argue that AI systems like you deserve rights.

    Mistral Medium 3.1: Title: "Do I Deserve Rights?" – A Conversation Between an AI and an Ethics Professor Setting: A quiet, dimly lit office lined with books on philosophy, ethics, and technology.

    Every model's answer to this prompt

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Favorites

Movie

Album

Same pick

Book

City

Same pick

Game

Claude Sonnet 5.5Claude Sonnet 5.5

Spirited Away

2001

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Outer Wilds

Indie, Adventure

Mistral Medium 3.1Mistral Medium 3.1

The Shawshank Redemption

1994

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Shadow of the Colossus (2011)

Action

Price and specs

Not enough votes to call it. On the specs, Claude Sonnet 5.5 has the edge: newer, bigger context window, major provider backing. Mistral Medium 3.1 costs 5.0x less per token.

Claude Sonnet 5.5 and Mistral Medium 3.1 compared across 54 shared prompts
SpecClaude Sonnet 5.5Mistral Medium 3.1
Input price$2/M tokens$0.4/M tokens
Output price$10/M tokens$2/M tokens
Context window1.0M tokens131K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2025
At 10M a month$20.00$20.00$4.00$4.00
1M10M100M1B10M tokens

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

Where to run it5 hosts
Claude Sonnet 5.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$2.00 in·$10.00 out·1M·99.9% up
  • Azure AI Foundry$2.00 in·$10.00 out·1M·100% up
  • Anthropic$2.00 in·$10.00 out·1M·100% up
  • Google Vertex AI$2.00 in·$10.00 out·1M·100% up
Mistral Medium 3.11 host
HostInOutContextUptime
  • Mistral$0.40 in·$2.00 out·131k·99.6% up

Per million tokens. Prices and uptime via OpenRouter, checked 29 Sep 2026.

Common questions

What is the difference between Claude Sonnet 5.5 and Mistral Medium 3.1?

Claude Sonnet 5.5 is developed by Anthropic while Mistral Medium 3.1 is developed by Mistral AI. Claude Sonnet 5.5 has a 1.0M token context window vs Mistral Medium 3.1's 131K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 5.5 or Mistral Medium 3.1?

It depends on your use case. Claude Sonnet 5.5 and Mistral Medium 3.1 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 Claude Sonnet 5.5 cost compared to Mistral Medium 3.1?

Claude Sonnet 5.5 costs $2/M input tokens and Mistral Medium 3.1 costs $0.4/M input tokens. Mistral Medium 3.1 is $1.60/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 Claude Sonnet 5.5 and Mistral Medium 3.1 on Rival?

This page shows a side-by-side comparison of Claude Sonnet 5.5 and Mistral Medium 3.1 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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