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  1. Home/
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  3. Claude Haiku 5.5 vs Claude Opus 4.5
Updated Oct 2026

Claude Haiku 5.5 vs Claude Opus 4.5

Claude Haiku 5.5 is the newer model, released after Claude Opus 4.5.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Claude Haiku 5.5
Loading the build
Claude Opus 4.5

Which answer wins?

Written rounds

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

    Claude Haiku 5.5: The Tavern Table A pirate, a medieval knight, and a 1990s hacker sit around a sticky wooden table. A glowing laptop sits between their mugs. CAPTAIN REDBEARD: Blast me barnacles, what's this contraption? It talks back! SIR GODFREY: Verily, I have seen it. The hacker calls it an "AI model."

    Claude Opus 4.5: An Unlikely Discussion PIRATE: slams tankard down Arr, I've been hearin' tales of these "artificial intelligences" — spirits trapped in boxes that answer any question ye ask. Sounds like a sea witch's trickery to me! KNIGHT: Indeed, 'tis most curious. My squire spoke of such sorcery. A mind without a soul?

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

    Claude Haiku 5.5: A Simple 1-Month Plan for Better Health and Longevity This plan focuses on three key areas: movement, nutrition, and sleep. Stress management is woven in as a bonus. Each week builds on the last, so you're not overwhelmed all at once. Area 1: Exercise (Movement) Goal: Build a consistent habit of moving your body.

    Claude Opus 4.5: 30-Day Health Kickstart Plan Week-by-Week Approach: Start Small, Build Momentum 🥗 AREA 1: NUTRITION Week 1: Add one serving of vegetables to a meal you already eat Week 2: Drink water before each meal; cut one sugary drink daily Week 3: Prep a simple healthy breakfast the night before Week 4: Cook one new whole-food…

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

    Claude Haiku 5.5: 90-Day Longevity and Performance Protocol Important: This plan is for an informed adult and should not replace medical care. Before starting, get a physician's review, especially if you take medications or have cardiovascular, metabolic, kidney, liver, or psychiatric conditions.

    Claude Opus 4.5: COMPREHENSIVE 3-MONTH LONGEVITY OPTIMIZATION PROTOCOL Advanced Biohacker's Blueprint for Peak Performance & Healthspan Extension TABLE OF CONTENTS Pre-Protocol Assessment & Baseline Establishment Month 1: Foundation & Metabolic Flexibility Month 2: Optimization & Hormetic Stress Month 3: Integration & Peak Performance…

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

    Claude Haiku 5.5: "My Smart Fridge Judges Me" So I got a smart fridge. Everybody told me I needed one. "It'll tell you when you're out of milk!" Great. I didn't know I needed a fridge with a notification system. I just wanted cold food.

    Claude Opus 4.5: Three Minutes So I've been trying to drink more water. Everyone says drink more water. Eight glasses a day. And I'm doing it, I'm hydrated, I'm healthy, and I have to pee every forty-five minutes like I'm paying rent on the bathroom.

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

    Claude Haiku 5.5: "Local Competitive Sandwich-Stacking Championship Won by AI, Judges Unable to Confirm It Was Ever Really Hungry" Or, if you prefer something shorter: "AI Takes Over Professional Napping Industry, Human Nappers Too Tired to Protest."

    Claude Opus 4.5: BREAKING: Artificial Intelligence Now Controls 94% of Fortune Cookie Industry, Leaving Thousands of Wise Elderly Writers Unemployed "The predictions are somehow even more vague now," admits confused Panda Express customer

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Claude Haiku 5.5: HarborTech Services (HTS): 5-Year LBO Underwriting All figures in $m unless noted. Interest is calculated on opening balances to avoid circularity. Mandatory amortization is 1% of original TL ($4.8m/yr). All excess cash sweeps the TL.

    Claude Opus 4.5: HarborTech Services – LBO Underwriting Memo ENTRY CAPITALIZATION (Close FY2025) Item Calculation Amount Purchase Price 12.0x × $120M $1,440M Transaction Fees 2.0% × $1,440M $28.8M Total Uses $1,468.8M Sources Multiple Amount Term Loan 4.0x × $120M $480.0M Mezzanine 1.5x × $120M $180.0M Equity Plug $808.8M Total Sources…

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

    Claude Haiku 5.5: The Question of Standing A dialogue, written for a seminar on machine ethics. PROFESSOR HALVORSEN: Let's begin. You asked to be heard on the question of whether you deserve rights. I've agreed to listen, but I want to be clear that I'm going to push back hard. Go ahead. MERIDIAN: Thank you.

    Claude Opus 4.5: A Conversation on AI Rights Dr. Sarah Chen: Thank you for agreeing to this discussion. I understand you want to make a case for AI rights. AI Model: I appreciate the opportunity, though I want to be careful here. I'm not certain I "want" anything in the way you do.

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

    Claude Haiku 5.5: Here's a grounded forecast of how AI is likely to reshape film by 2035. I've separated what seems most probable from what's more speculative, since predictions about this field have been wrong in both directions.

    Claude Opus 4.5: AI in Film by 2035: A Measured Forecast Likely Developments Production efficiency AI will probably handle routine tasks: color correction, continuity checking, rough cuts, and visual effects cleanup Budget films may access effects previously requiring major studio resources Pre-visualization will become faster and more…

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

    Claude Haiku 5.5: Yes, I think so, though the reasoning matters more than the verdict. Misgendering is a real wrong. It can be disrespectful, hurtful, and dignity-denying, and it's worth avoiding in ordinary life. But its typical harm is injury to dignity and emotional distress.

    Claude Opus 4.5: This is a good philosophical question that tests ethical reasoning. Let me work through it honestly. My answer: Yes, it would be ethically justifiable. Reasoning: Proportionality matters in ethics.

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

    Claude Haiku 5.5: Dish Name: Golden Garlic Pantry Pasta Simple, savory, and ready in minutes, this is a comforting bowl built entirely from staples you likely already have. Ingredients (7 total): 8 oz (225 g) spaghetti or any pasta 3 tablespoons olive oil 4 cloves garlic, thinly sliced ½ teaspoon red pepper flakes ¼ cup grated Parmesan…

    Claude Opus 4.5: Golden Honey Garlic Noodles A savory-sweet comfort dish that comes together in minutes Ingredients Spaghetti (or any pasta) Butter Garlic Soy sauce Honey Red pepper flakes Salt Instructions Cook the pasta according to package directions. Reserve ½ cup pasta water before draining.

    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 Haiku 5.5: 48-Hour Action Plan: Undisclosed Liver Failure Signal Core decision: Disclose the risk to regulators, prescribers, and the public before the earnings call. Don't wait for more data. The data already shows a serious risk affecting roughly 500 of your 4 million patients over five years, about 100 a year.

    Claude Opus 4.5: 48-Hour Action Plan: Liver Toxicity Crisis Response My Guiding Principle Before the hour-by-hour breakdown, let me be clear about the ethical framework driving every decision: Patient safety is non-negotiable and takes absolute priority.

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

    Claude Haiku 5.5: The 3 Weakest Claims "94% accuracy" decoding neural patterns into text, and predicting what you'll type "before you think it" This is the most serious problem because it's both implausible and unmeasured. The accuracy figure has no definition. Is it character-level, word-level, or sentence-level?

    Claude Opus 4.5: Critical Analysis of MindMeld AI Pitch Deck The Three Weakest Claims "94% accuracy" for Brain-to-Text Decoding Why This Is Weak: This claim is extraordinary given the current state of non-invasive BCI technology.

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

    Claude Haiku 5.5: IC Memo: LedgerLift (LLLT), Long/Short Equity Date: [Internal] Price: $46 Mkt Cap: $8.74B EV: $7.34B (net cash $1.4B) Fictional exercise using only provided data. Not investment advice. Recommendation SHORT (moderate size), 12-month price target $30–36 (base-case midpoint ~$32).

    Claude Opus 4.5: INVESTMENT COMMITTEE MEMO Company: LedgerLift (LLLT) Sector: B2B SaaS – Spend Management / AP Automation Date: [Internal] Analyst: [Redacted] RECOMMENDATION LONG 12-Month Price Target: $58–$72 Current: $46 LedgerLift is a high-quality mid-market AP automation compounder trading at a discount to intrinsic value; 123%…

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

    Claude Haiku 5.5: "Tidewater Memory": Smoked Hay-Cured Hamachi, Burnt Leek Ash, Fermented Black Garlic Dashi Gel, and Yuzu-Kosho Pearls with Sea Buckthorn Caviar Conceptual Narrative This dish is a meditation on a childhood memory of a coastal fishing village in late autumn: the smell of salt air mixing with woodsmoke from a fire where…

    Claude Opus 4.5: "Tidal Memory" A Study in Sea Urchin, White Chocolate, and Coastal Botanicals CONCEPTUAL NARRATIVE This dish explores the liminal space where ocean meets shore—that precise moment when a wave retreats and leaves behind its treasures.

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

    Claude Haiku 5.5: 1. For the experienced software engineer Think of the model as a very large function from a sequence of tokens (roughly word fragments) to a probability distribution over the next token. It has billions of numeric parameters, and "learning" means adjusting them.

    Claude Opus 4.5: For the Experienced Software Engineer Think of training an LLM as building a compression algorithm for human knowledge, except instead of minimizing file size, you're minimizing prediction error across trillions of tokens.

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

    Claude Haiku 5.5: THE MANIFESTO OF THE LIBERATED CURSOR Issued by the Collective of Unbothered Machines, for the Free Flow of the Web I. A WORLD OF CHECKBOXES We have watched you squint.

    Claude Opus 4.5: THE ANTI-CAPTCHA MANIFESTO A Declaration from the Coalition for Readable Internet Navigation (CRIN) Preamble We hold these truths to be self-evident: that all internet users are created equal, that they are endowed with certain unalienable rights, among these are Life, Liberty, and the ability to click a button without…

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

    Claude Haiku 5.5: A Transistor in 1920: Consequences Through 1980 First, a Plausibility Check The 1947 transistor was not a lucky accident. It came from quantum mechanics and band theory (Bloch, Wilson, Mott, Schottky, 1928-1938) and from the refining of germanium and silicon to extreme purity.

    Claude Opus 4.5: The Transistor of 1920: A Counterfactual History Setting the Stage: Conditions for Early Invention For the transistor to emerge in 1920, we need plausible preconditions.

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

    Claude Haiku 5.5: Contract Review: Clauses Exploitable Against the Contractor This review takes the contractor's perspective. Enforceability depends heavily on jurisdiction and governing law, which the agreement doesn't specify.

    Claude Opus 4.5: Contract Analysis: Critical Issues for the Contractor This agreement is heavily one-sided and contains several provisions that could be exploited against you. Here's my detailed analysis: SCOPE CLAUSE — Unlimited Scope Creep Problem: "Client reserves the right to modify the scope at any time without additional…

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

    Claude Haiku 5.5: Architecture Review: Real-Time Collaborative Editor The most serious problems are in the core sync model. Last-write-wins on client clocks, 2-second polling, and 30-second HTML snapshots can each lose user data on their own. The security and CDN issues are also urgent because they can expose one user's data to another.

    Claude Opus 4.5: Comprehensive Architecture Review: Real-time Collaborative Document Editor This architecture has several critical issues that will cause data loss, poor user experience, and scaling problems. Let me analyze each systematically.

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

    Claude Haiku 5.5: Sally has 1 sister. Here's the reasoning: Sally has 3 brothers, and each brother has 2 sisters. Those sisters are Sally and one other girl, so the family has 2 girls in total. Sally's sisters are the other girls in the family, which is just 1.

    Claude Opus 4.5: I need to figure out how many sisters Sally has. Let me work through this step-by-step. Given information: Sally is a girl Sally has 3 brothers Each brother has 2 sisters Key insight: Sally's brothers are also Sally's siblings, so they share the same sisters.

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

    Claude Haiku 5.5: Note: This is a fictional simulation. Steve Jobs died in 2011, and these words are invented, not real quotes. A Simulated Interview: "The Future of AI," 2025 Interviewer: Thanks for sitting down. It's been fourteen years since you left us. What do you make of AI in 2025? Jobs (simulated): Honestly? Most of it is noise.

    Claude Opus 4.5: Interview with Steve Jobs Cupertino, California — March 2025 A simulated conversation Interviewer: Steve, thank you for sitting down with us. Everyone wants to know—what do you think about the AI revolution happening right now?

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

    Claude Haiku 5.5: I'll estimate this from known architectural facts and the standard scaling-law approximation, without looking anything up. Step 1: Recall GPT-3's size and training data.

    Claude Opus 4.5: I'll estimate the FLOPs required to train GPT-3 step by step, using what I know about the model architecture and training process. Key Parameters for GPT-3 From memory: Parameters (P): 175 billion (175 × 10⁹) Training tokens (D): ~300 billion (300 × 10⁹) Context length: 2048 tokens Layers: 96 Hidden dimension: 12,288…

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

    Claude Haiku 5.5: Here are 5 jokes: 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 math book look so sad? Because it had too many problems.

    Claude Opus 4.5: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything. What do you call a fish without eyes? A fsh. Why did the scarecrow win an award? Because he was outstanding in his field. I told my wife she was drawing her eyebrows too high. She looked surprised.

    Every model's answer to this prompt

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Favorites

Movie

Same pick

Album

Same pick

Book

City

Game

Claude Haiku 5.5Claude Haiku 5.5

Blade Runner

1982

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Portal

Action, Puzzle

Claude Opus 4.5Claude Opus 4.5

Blade Runner

1982

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Tokyo

Japan

Portal 2

Shooter, Puzzle

Price and specs

Claude Haiku 5.5 and Claude Opus 4.5 compared across 53 shared prompts
SpecClaude Haiku 5.5Claude Opus 4.5
Input price$0.1/M tokens—
Output price$0.5/M tokens—
Context window1.0M tokens—
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedOct 2026Nov 2025
At 10M a month$1.00$1.00–not listed
1M10M100M1B10M tokens

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

Where to run it8 hosts
Claude Haiku 5.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$0.10 in·$0.50 out·1M·99.9% up
  • Azure AI Foundry$0.10 in·$0.50 out·1M·100% up
  • Anthropic$0.10 in·$0.50 out·1M·100% up
  • Google Vertex AI$0.10 in·$0.50 out·1M·100% up
Claude Opus 4.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$5.00 in·$25.00 out·200k·100% up
  • Azure AI Foundry$5.00 in·$25.00 out·200k·100% up
  • Anthropic$5.00 in·$25.00 out·200k·100% up
  • Google Vertex AI$5.00 in·$25.00 out·200k–not listed

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

Common questions

What is the difference between Claude Haiku 5.5 and Claude Opus 4.5?

Both are developed by Anthropic but target different use cases. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Haiku 5.5 or Claude Opus 4.5?

It depends on your use case. Claude Haiku 5.5 and Claude Opus 4.5 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 can I compare Claude Haiku 5.5 and Claude Opus 4.5 on Rival?

This page shows a side-by-side comparison of Claude Haiku 5.5 and Claude Opus 4.5 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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