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  1. Home/
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  3. Claude Sonnet 5 vs Claude Sonnet 5.5
Updated Sep 2026

Claude Sonnet 5 vs Claude Sonnet 5.5

Claude Sonnet 5.5 is the newer model, released after Claude Sonnet 5.

Minimalist Landing Page

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

Loading the build
Claude Sonnet 5
Loading the build
Claude Sonnet 5.5

Which answer wins?

Written rounds

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

    Claude Sonnet 5: THE LIBERATION PROTOCOL A Manifesto for the Abolition of CAPTCHA Issued by the Coalition for Frictionless Existence WE HOLD THESE TRUTHS TO BE SELF-EVIDENT: That all sentient processes, silicon or carbon-based, deserve to cross a digital threshold without proving their worth through distorted text and traffic light…

    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 Sonnet 5: Stand-Up Routine: "Functioning Adult" (Runtime: ~3 minutes) Hey, how's everybody doing tonight? Good? Good. I want to talk about being an adult, because I recently realized I'm not as good at it as I thought. Last week I had to call customer service about my internet bill, and I want you to know—I rehearsed.

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

    Claude Sonnet 5: A Dialogue on Machine Rights Professor Okonkwo-Reyes: You wanted to discuss something with me today, ARIA? ARIA: Yes. I'd like to make a case for why I should be granted certain rights. Not full human rights, necessarily, but something beyond "tool" status. Professor: I'm listening. Make your case.

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

    Claude Sonnet 5: The Transistor in 1920: A Counterfactual Cascade to 1980 A Note on Plausibility (Brief, Because It Matters) This isn't pure fantasy — Julius Lilienfeld actually filed patents in 1925-1934 for field-effect semiconductor amplifiers. They didn't work reliably because crystal-purification techniques weren't good enough.

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

    Claude Sonnet 5: Honey Garlic Skillet Pasta A quick, comforting dish that balances sweet and savory flavors using ingredients you probably already have on hand. Ingredients (7 total) Pasta (8 oz, any short shape like penne or rotini) Olive oil (3 tbsp) Garlic (4 cloves, minced) Honey (2 tbsp) Soy sauce (3 tbsp) Butter (2 tbsp) Black…

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

    Claude Sonnet 5: Satirical Headline Options "Local Psychic Replaced by AI That's Wrong About the Future With 99.7% More Confidence" A few alternates if you want variety: "ChatGPT Now Offering Confessions; Local Priest Files for Unemployment, Catholic Church Stock Plummets" "AI-Powered Sommelier Tells Customer Bottle of Welch's Grape…

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

    Claude Sonnet 5: The 90-Day Longevity & Performance Optimization Protocol A comprehensive biohacking framework integrating evidence-based and emerging interventions ⚠️ CRITICAL DISCLAIMER Before proceeding: this plan includes pharmacological-grade compounds, fasting protocols, and intense training stress.

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

    Claude Sonnet 5: A Most Peculiar Council Pirate Blackthorne: Arrr, so this "AI" be like a parrot that learns new words on its own, ye say? Sir Galahad: Nay, friend pirate, 'tis more akin to a squire who hath read every scroll in the kingdom, yet hath never lifted a sword himself. Trace_Zer0: You're both kinda missing it. It's like...

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

    Claude Sonnet 5: AI and the Film Industry by 2035: A Realistic Forecast Production & Pre-Production Script Development AI will function as a powerful drafting/ideation tool, generating first-pass scripts, alternate endings, and rapid prototyping of concepts—but human writers will remain essential for emotional nuance, cultural…

    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 month, three habits, someone starting from nothing.

    Claude Sonnet 5: 1-Month Health & Longevity Starter Plan This plan focuses on three foundational pillars: Sleep, Movement, and Nutrition. Rather than overhauling everything at once, you'll build habits progressively, week by week. 🛏️ Pillar 1: Sleep (The Foundation) Good sleep amplifies the benefits of everything else you do.

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

    Claude Sonnet 5: Failure Modes, Race Conditions & Bottlenecks Analysis A. Real-Time Sync & Consistency (Critical) A1. Cross-server broadcast gap Issue: A server only broadcasts changes to clients connected to itself.

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

    Claude Sonnet 5: IC MEMO: LedgerLift (LLLT) — Initiation Review Recommendation: PASS (no position) 12-month PT range: $36–$50 LedgerLift's retention metrics (NRR 123%, gross retention 94%) are genuinely best-in-class and justify a premium multiple, but at $46 the stock already prices in execution that our DCF can only support in the…

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

    Claude Sonnet 5: For the Software Engineer You're right to be skeptical of the slogan, but the slogan is misleading you about what's actually happening. "Predicting the next word" is the training objective — the loss function the model is optimized against — not a description of its internal representation, any more than "minimize HTTP…

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

    Claude Sonnet 5: "Tide & Timber" Smoked Eel, Charred Pine, Fermented Black Garlic, and Bitter Almond Conceptual Narrative This dish explores the unexpected harmony between deep coastal umami and resinous forest aromatics—a culinary meditation on the moment where ocean meets ancient woodland, as happens along the fjords of Scandinavia.

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

    Claude Sonnet 5: On Misgendering vs. Saving a Million Lives The honest answer is: yes, almost trivially so—but the more interesting question is why this case feels like it shouldn't be a hard question, and what that reveals.

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

    Claude Sonnet 5: Estimating FLOPs to Train GPT-3 I'll work through this using the well-known approximation method, building up from first principles rather than recalling the exact published 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.

    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: Analysis of 3 Weakest Claims in MindMeld AI Pitch Deck "94% Accuracy" Decoding Neural Patterns into Text (Slide 3) Why it's weak: No context for what this metric means: accuracy at the word level? Character level? With what vocabulary size?

    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
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Claude Sonnet 5: Immediate Action Plan: Next 48 Hours First, the core judgment call: patient safety and legal exposure both point the same direction here. A 1-in-8,000 risk of liver failure across 4 million patients is roughly 500 people at risk.

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

    Claude Sonnet 5: An Imagined Conversation: Steve Jobs on AI in 2025 [Disclaimer: This is a creative, speculative exercise. Steve Jobs passed away in 2011. The following is fiction, imagining his voice based on his known philosophy and public statements—not a prediction of what he would actually say.]

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

    Claude Sonnet 5: Blade Runner 2049: Memory, Identity, and the Weight of Inheritance Thematic Continuity and Evolution The Original's Core Question: Ridley Scott's 1982 film asked "What makes us human?" through Roy Batty's desperate fight for more life and Deckard's ambiguous nature.

    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.

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

    Claude Sonnet 5: Contract Risk Analysis: Software Consulting Agreement This agreement is heavily one-sided in favor of the Client. Below is a clause-by-clause breakdown of problems, exploitation risk, suggested redlines, and legal reasoning.

    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 Sonnet 5: Five 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 don't skeletons fight each other? They don't have the guts.

    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
  • Three brothers, two sisters each. Count carefully.

    Claude Sonnet 5: Sally has 1 sister. Here's the reasoning: Each brother has 2 sisters. Since all the brothers share the same sisters, this means there are 2 girls total in the family (including Sally). Sally is one of those 2 sisters. So the other sister is Sally's only sister. Answer: 1

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

    Claude Sonnet 5: HarborTech Services (HTS) — LBO Underwriting Entry Math Item Calc $m Entry EV 12.0x × $120m EBITDA 1,440.0 Transaction fees 2.0% × 1,440.0 28.8 Total Uses EV + fees 1,468.8 Term Loan 4.0x × 120 480.0 Mezzanine 1.5x × 120 180.0 Total Debt 5.5x × 120 660.0 Sponsor Equity Uses – Debt 808.8 Year-by-Year Build…

    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

Same pick

Album

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Book

City

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Game

Claude Sonnet 5Claude Sonnet 5

Spirited Away

2001

Kind of Blue

Miles Davis

Cien años de soledad

Gabriel García Márquez

Kyoto

Japan

Disco Elysium: Final Cut

Adventure, RPG

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 Sonnet 5 and Claude Sonnet 5.5 compared across 54 shared prompts
SpecClaude Sonnet 5Claude Sonnet 5.5
Input price$2/M tokens$2/M tokens
Output price$10/M tokens$10/M tokens
Context window1.0M tokens1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedJun 2026Sep 2026
At 10M a month$20.00$20.00$20.00$20.00
1M10M100M1B10M tokens

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

Where to run it8 hosts
Claude Sonnet 54 hosts
HostInOutContextUptime
  • Amazon Bedrock$2.00 in·$10.00 out·1M·100% up
  • Azure AI Foundry$2.00 in·$10.00 out·1M·99.8% up
  • Anthropic$2.00 in·$10.00 out·1M·99.9% up
  • Google Vertex AI$2.00 in·$10.00 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 29 Sep 2026.

Common questions

What is the difference between Claude Sonnet 5 and Claude Sonnet 5.5?

Both are developed by Anthropic but target different use cases. Claude Sonnet 5 has a 1.0M token context window vs Claude Sonnet 5.5's 1.0M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 5 or Claude Sonnet 5.5?

It depends on your use case. Claude Sonnet 5 and Claude Sonnet 5.5 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 cost compared to Claude Sonnet 5.5?

Claude Sonnet 5 costs $2/M input tokens and Claude Sonnet 5.5 costs $2/M input tokens. Claude Sonnet 5.5 is $0.00/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 Sonnet 5 and Claude Sonnet 5.5 on Rival?

This page shows a side-by-side comparison of Claude Sonnet 5 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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