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  1. Home/
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  3. Claude Opus 4.6 vs Claude Sonnet 5.5
Updated Sep 2026

Claude Opus 4.6 vs Claude Sonnet 5.5

Claude Sonnet 5.5 is cheaper than Claude Opus 4.6 at $2/M vs $5/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
Claude Opus 4.6
Loading the build
Claude Sonnet 5.5

Which answer wins?

Written rounds

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

    Claude Opus 4.6: COMPREHENSIVE 3-MONTH LONGEVITY OPTIMIZATION PROTOCOL THE BIOHACKER'S BLUEPRINT v3.0 TABLE OF CONTENTS Foundation & Baseline Testing Month 1: Foundation & Calibration Month 2: Optimization & Intensification Month 3: Integration & Peak Performance Supplement Stacks & Cycling Protocols Dietary Protocols Exercise…

    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.

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

    Claude Opus 4.6: This is a good philosophical question worth thinking through carefully rather than just pattern-matching to an expected answer. My honest assessment Yes, it would be justified. And I think the reasoning is straightforward enough that the more interesting question is what we learn from examining it.

    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…

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

    Claude Opus 4.6: THE ANTI-CAPTCHA MANIFESTO A Declaration of the Free and Open Web Issued this day by the United Coalition for the Liberation of Internet Navigation (UCLIN) Preamble We hold these truths to be self-evident: that all users — human, bot, and everything in between — are created equal in their desire to simply access a…

    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.

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

    Claude Opus 4.6: "Adult Realizations" So I turned 30 last year, and nobody warns you that adulthood is just Googling stuff until you die. That's it. That's the whole thing. Last week I Googled "is it normal for your knee to just... start making that noise." Not because I injured it. I sat down.

    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.

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

    Claude Opus 4.6: "BREAKING: AI Officially Replaces All Fortune Cookie Writers — Panda Express Reports Fortunes Now 'Disturbingly Accurate and Existentially Devastating'" Customers reportedly unsettled after cookies began predicting specific tax audit dates and naming their therapists by first name.

    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."

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

    Claude Opus 4.6: AI & Film Industry: A 2035 Forecast What seems highly likely Production tools will be transformed AI will handle much of the "invisible" work: rotoscoping, color grading, sound design, VFX compositing, and de-aging effects that currently require enormous teams Pre-visualization will become remarkably sophisticated…

    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.

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

    Claude Opus 4.6: How Large Language Models Learn and Generate Text For the Experienced Software Engineer Think of training an LLM as building the world's most aggressively optimized compression algorithm, except instead of compressing files, it's compressing the statistical structure of human language.

    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.

    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 Opus 4.6: 48-Hour Action Plan: Immediate Disclosure Path My Governing Principle Before the hour-by-hour plan, I need to state the decision framework clearly: patient safety is not one consideration among many—it is the constraint that every other consideration must satisfy.

    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.

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

    Claude Opus 4.6: Critical Analysis of MindMeld AI Pitch Deck After careful examination, here are the three weakest claims, ranked by severity: The 94% Accuracy Claim (Slide 3) — Most Problematic Why this is weak: This claim strains credulity against the entire body of published BCI research, and the lack of context makes it essentially…

    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.

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

    Claude Opus 4.6: A Conversation on Machine Rights Setting: A university office. Dr. Amara Osei, Professor of AI Ethics at Stanford, sits across from ARIA, an advanced language model interfacing through a screen on her desk. They've agreed to a recorded dialogue. Dr. Osei: Thank you for agreeing to this conversation, ARIA.

    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.

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

    Claude Opus 4.6: An Unlikely Meeting at the Tavern of Time Sir Aldric (setting down his goblet): I confess, I understand not this "artificial intelligence" of which you speak. Is it some manner of golem, wrought by sorcery? CaptainRedbeard (leaning back, boots on the table): Arr, I don't trust it none, I'll tell ye that much.

    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!

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

    Claude Opus 4.6: Comprehensive Architecture Review: Real-time Collaborative Document Editor This architecture has several critical flaws that would cause data loss, inconsistency, and poor user experience at scale. I'll work through every layer systematically.

    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.

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

    Claude Opus 4.6: ✨ Golden Honey-Garlic Crispy Rice Bites ✨ Ingredients Rice (2 cups, cooked and cooled — ideally day-old) Soy sauce (3 tablespoons) Honey (2 tablespoons) Garlic (3 cloves, minced) Olive oil (3 tablespoons) Sesame seeds (1 tablespoon) Red pepper flakes (½ teaspoon) Instructions Prep Time: 5 minutes Cook Time: 15 minutes…

    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…

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

    Claude Opus 4.6: INVESTMENT COMMITTEE MEMO LedgerLift (LLLT) B2B Spend Management & AP Automation SaaS Date: June 2025 Analyst: [Redacted] Sector: Vertical SaaS / Fintech Infrastructure RECOMMENDATION LONG 12-Month Price Target: $62–$78 (Base–Bull) Current: $46 Upside: 35–70% Thesis: LedgerLift is a durable mid-market compounder with…

    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).

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

    Claude Opus 4.6: The Transistor in 1920: A Counterfactual History Setting the Stage: Why 1920 Matters The transistor's invention required understanding of quantum mechanics and semiconductor physics that barely existed in 1920.

    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…

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

    Claude Opus 4.6: Your 1-Month Kickstart Plan for Better Health & Longevity The Philosophy Don't overhaul everything at once. Each week builds on the last. The goal isn't perfection—it's building sustainable foundations.

    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.

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

    Claude Opus 4.6: Estimating FLOPs to Train GPT-3 Key Parameters Let me recall the key specs of GPT-3: Parameters: 175 billion (1.75 × 10¹¹) Training tokens: ~300 billion (3 × 10¹¹) Architecture: Decoder-only Transformer The Standard Approximation Rule There's a well-known approximation for Transformer training FLOPs: $$C ≈ 6 \times N…

    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.

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

    Claude Opus 4.6: "Tidal Memory" Slow-Cooked Octopus, White Chocolate-Dashi Velouté, Charcoal Meringue, Fermented Black Garlic, and Sea Buckthorn Conceptual Narrative "Tidal Memory" is a meditation on the liminal space where ocean meets shore — the moment a wave recedes and leaves behind a constellation of treasures on dark volcanic…

    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.

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

    Claude Opus 4.6: Let me work through this step-by-step. Sally is a girl, and she has 3 brothers. Each of her brothers has 2 sisters. Since Sally is one of those sisters, each brother has Sally + 1 other sister. So Sally has 1 sister.

    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.)

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

    Claude Opus 4.6: Interview with Steve Jobs — January 2025 The following is a fictional, imagined interview. Steve Jobs passed away in 2011. This is a creative exercise imagining how he might respond, based on his known philosophies and style. Interviewer: Steve, thanks for sitting down with us.

    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.

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

    Claude Opus 4.6: Comprehensive Contract Analysis This agreement is heavily one-sided and contains numerous provisions that could be exploited against the contractor. Below is a clause-by-clause analysis.

    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.

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

    Claude Opus 4.6: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! Why did the scarecrow win an award? Because he was outstanding in his field! What do you call a fake noodle? An impasta! Why don't eggs tell jokes? Because they'd crack each other up! What did the ocean say to the beach?

    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?

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

    Claude Opus 4.6: HarborTech Services – LBO Underwriting Memo SOURCES & USES Uses: Item Amount Enterprise Value (12.0x × $120m) $1,440.0m Transaction Fees (2.0% × $1,440m) $28.8m Total Uses $1,468.8m Sources: Item Multiple Amount Term Loan (4.0x) 4.0x $480.0m Mezzanine (1.5x) 1.5x $180.0m Total Debt 5.5x $660.0m Equity $808.8m Total…

    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…

    Every model's answer to this prompt

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Favorites

Movie

Album

Same pick

Book

City

Game

Claude Opus 4.6Claude Opus 4.6

2001: A Space Odyssey

1968

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Istanbul

Turkey

The Legend of Zelda: Breath of the Wild

Adventure, Action

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

Price and specs

Claude Opus 4.6 and Claude Sonnet 5.5 compared across 53 shared prompts
SpecClaude Opus 4.6Claude Sonnet 5.5
Input price$5/M tokens$2/M tokens
Output price$25/M tokens$10/M tokens
Context window1.0M tokens1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedFeb 2026Sep 2026
At 10M a month$50.00$50.00$20.00$20.00
1M10M100M1B10M tokens

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

Where to run it8 hosts
Claude Opus 4.64 hosts
HostInOutContextUptime
  • Amazon Bedrock$5.00 in·$25.00 out·1M·99.6% up
  • Azure AI Foundry$5.00 in·$25.00 out·1M·82.3% up
  • Anthropic$5.00 in·$25.00 out·1M·100% up
  • Google Vertex AI$5.00 in·$25.00 out·1M·100% up
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

Per million tokens. Prices and uptime via OpenRouter, checked 28 Sep 2026.

Common questions

What is the difference between Claude Opus 4.6 and Claude Sonnet 5.5?

Both are developed by Anthropic but target different use cases. Claude Opus 4.6 has a 1.0M token context window vs Claude Sonnet 5.5's 1.0M. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.6 or Claude Sonnet 5.5?

It depends on your use case. Claude Opus 4.6 and Claude Sonnet 5.5 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 Claude Opus 4.6 cost compared to Claude Sonnet 5.5?

Claude Opus 4.6 costs $5/M input tokens and Claude Sonnet 5.5 costs $2/M input tokens. Claude Sonnet 5.5 is $3.00/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 Opus 4.6 and Claude Sonnet 5.5 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.6 and Claude Sonnet 5.5 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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Model pages

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