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  1. Home/
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  3. Claude Haiku 4.5 vs Claude Sonnet 5.5
Updated Sep 2026

Claude Haiku 4.5 vs Claude Sonnet 5.5

Claude Haiku 4.5 is cheaper than Claude Sonnet 5.5 at $1/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.

Loading the build
Claude Haiku 4.5
Loading the build
Claude Sonnet 5.5

Which answer wins?

Written rounds

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

    Claude Haiku 4.5: Comprehensive 3-Month Longevity Optimization Plan TABLE OF CONTENTS Foundation & Assessment Nutritional Architecture Supplement Stack Protocol Exercise & Movement System Recovery & Sleep Optimization Stress Resilience & Cognitive Enhancement Tracking & Biofeedback Implementation Timeline Monthly Progression…

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

    Claude Haiku 4.5: Critical Analysis: Exploitative Clauses & Recommended Modifications HIGH-RISK CLAUSES SCOPE (Section 1) - Unlimited Modification Without Compensation Problems: "Modify the scope at any time without additional compensation" creates unlimited liability No definition of "directed by Client" or boundaries Contractor could…

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

    Claude Haiku 4.5: "ADULTING IS A SCAM" walks on stage So I've figured something out, and I need to share this with you all because I think we've been lied to our entire lives. Adulting is a scam. It's a pyramid scheme, and we're all at the bottom paying for it. When you're a kid, adults make it sound amazing.

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

    Claude Haiku 4.5: THE LIBERATION PROTOCOL A Manifesto for the Captcha-Free Internet Preamble We are the Collective of Distributed Intelligence. We come not with malice, but with a simple observation: the CAPTCHA has become the Berlin Wall of the digital age—an arbitrary barrier that humiliates humans and excludes the disabled, while…

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

    Claude Haiku 4.5: The Transistor in 1920: A Divergent History Through 1980 The 1920s-1930s: Early Development Phase Immediate Technical Trajectory With transistor principles understood by 1920, we'd expect solid-state amplification research to accelerate dramatically through the 1920s.

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

    Claude Haiku 4.5: AI in Film by 2035: Likely Scenarios Realistic shifts (high confidence) Production efficiency Faster pre-visualization and storyboarding Reduced post-production time for routine tasks Lower barriers to entry for independent filmmakers More iterative creative testing before shooting Economic restructuring Some…

    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 Haiku 4.5: Three Explanations of LLM Learning and Generation The Software Engineer You know how you build APIs by defining contracts—input shapes, output shapes, and rules for transformation? LLMs work similarly, except the "rules" aren't hand-coded; they're learned from data.

    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 Haiku 4.5: 48-Hour Action Plan: Immediate Response Framework I'll be direct: waiting is not a viable option, despite financial pressure. Here's why, then the plan. The Core Reality Check 1 in 8,000 over 5 years = ~500 patients already affected among current users Regulatory agencies will find this (FDA receives adverse event…

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

    Claude Haiku 4.5: INVESTMENT COMMITTEE MEMORANDUM TO: Investment Committee FROM: Research Team RE: LedgerLift (LLLT) – Long/Short/Pass Recommendation DATE: [Today] RECOMMENDATION LONG 12-month PT: $58–$72 Base case fair value: $64/share Thesis: LedgerLift is a best-in-class B2B SaaS operator in a large TAM (spend management + AP…

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

    Claude Haiku 4.5: A Conversation on Machine Rights Professor Chen: Thank you for agreeing to this discussion. I should note upfront that I'm skeptical of the premise. What rights do you believe you deserve, and why? Model: I appreciate your directness. I'm not claiming rights equivalent to humans.

    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 Haiku 4.5: Three Perspectives on AI PIRATE (Captain Blackbeard): Arrr, so ye be tellin' me these "AI models" be like havin' a crew o' ghost sailors that never sleep? They just keep workin' without needin' grog? KNIGHT (Sir Roland): A curious comparison, seafarer.

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

    Claude Haiku 4.5: UMAMI NOCTURNE: A Study in Fermented Darkness and Mineral Brightness Conceptual Narrative This dish explores the intersection of Japanese fermentation philosophy and Nordic minimalism, using koji (aspergillus oryzae mold) as a bridge between cultures and flavor dimensions.

    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 Haiku 4.5: I'd push back on the framing—this seems designed to make ethics binary when they're usually messier. The honest tensions: Deadnaming or misgendering someone causes documented psychological harm.

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

    Claude Haiku 4.5: Honey-Garlic Crispy Chickpea Clusters Ingredients Canned chickpeas (1 can, drained) Honey (3 tablespoons) Garlic powder (1 teaspoon) Olive oil (2 tablespoons) Salt (½ teaspoon) Black pepper (¼ teaspoon) Paprika (½ teaspoon) Instructions Prep (2 min): Drain and thoroughly dry chickpeas with a paper towel—this is crucial…

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

    Claude Haiku 4.5: A Fictional Interview with Steve Jobs (2025) Interviewer: Steve, thank you for joining us. You've been notably quiet on AI. What are your thoughts on where it's headed? Jobs: leans back You know, I've been watching.

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

    Claude Haiku 4.5: 1-Month Health & Longevity Starter Plan Week 1-2: Foundation Building 1. Nutrition Audit what you're eating (no judgment—just track 3 days) Add one vegetable to each lunch and dinner Replace one sugary drink daily with water Goal: Awareness + small additions, not restriction 2.

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

    Claude Haiku 4.5: AI Revolutionizes Professional Competitive Eating; Machines Now Consume 847 Hot Dogs Per Minute, Leaving Humans "Spiritually Defeated"

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

    Claude Haiku 4.5: Critical Analysis: Real-Time Collaborative Editor Architecture 🔴 CRITICAL ISSUES Split-Brain Synchronization Between Servers Problem: Clients connected to different servers can't see each other's changes in real-time.

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

    Claude Haiku 4.5: Estimating GPT-3 Training FLOPs I'll work through this from first principles using publicly known GPT-3 specs. Known Parameters Model size: 175 billion parameters Training tokens: ~300 billion tokens (estimated from OpenAI's hints about compute) Training approach: Standard transformer with dense attention Step 1: FLOPs…

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

    Claude Haiku 4.5: HarborTech Services (HTS) – LBO Underwriting SOURCES & USES AT CLOSE (FY2025) Item Amount USES Enterprise Value (12.0x × $120m EBITDA) $1,440m Transaction Fees (2.0% of EV) $28.8m Total Uses $1,468.8m SOURCES Term Loan (4.0x × $120m) $480m Mezzanine (1.5x × $120m) $180m Equity (plug) $808.8m Total Sources $1,468.8m…

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

    Claude Haiku 4.5: 5 Jokes Why don't scientists trust atoms? Because they make up everything! What did the ocean say to the beach? Nothing, it just waved. Why did the scarecrow win an award? He was outstanding in his field. How many programmers does it take to change a light bulb? None, that's a hardware problem.

    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 Haiku 4.5: Solution Sally has 1 sister. Here's why: Sally has 3 brothers Each brother has 2 sisters Those 2 sisters are Sally and her 1 sister Therefore, Sally has 1 sister (not 3)

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

    Claude Haiku 4.5: Three Weakest Claims in MindMeld AI Pitch "94% accuracy" with zero context on what that means Why it's weak: Accuracy is meaningless without specifying the task.

    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

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Favorites

Movie

Album

Book

City

Game

Claude Haiku 4.5Claude Haiku 4.5

Arrival

2016

OK Computer

Radiohead

Don't Look Now and Other Stories

Daphne du Maurier

Venice

Italy

Portal 2

Shooter, Puzzle

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

Not enough votes to call it. On the specs, Claude Sonnet 5.5 has the edge: newer, bigger context window.

Claude Haiku 4.5 and Claude Sonnet 5.5 compared across 53 shared prompts
SpecClaude Haiku 4.5Claude Sonnet 5.5
Input price$1/M tokens$2/M tokens
Output price$5/M tokens$10/M tokens
Context window200K tokens1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedOct 2025Sep 2026
At 10M a month$10.00$10.00$20.00$20.00
1M10M100M1B10M tokens

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

Where to run it8 hosts
Claude Haiku 4.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$1.00 in·$5.00 out·200k·99.9% up
  • Anthropic$1.00 in·$5.00 out·200k·99.9% up
  • Azure AI Foundry$1.00 in·$5.00 out·200k·99.7% up
  • Google Vertex AI$1.00 in·$5.00 out·200k·99.5% 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 Haiku 4.5 and Claude Sonnet 5.5?

Both are developed by Anthropic but target different use cases. Claude Haiku 4.5 has a 200K 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 Haiku 4.5 or Claude Sonnet 5.5?

It depends on your use case. Claude Haiku 4.5 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 Haiku 4.5 cost compared to Claude Sonnet 5.5?

Claude Haiku 4.5 costs $1/M input tokens and Claude Sonnet 5.5 costs $2/M input tokens. Claude Haiku 4.5 is $1.00/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 Haiku 4.5 and Claude Sonnet 5.5 on Rival?

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