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  1. Home/
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  3. Claude Sonnet 4.5 vs OpenRouter Fusion · Quality (Jun 2026)
Updated Jun 2026

Claude Sonnet 4.5 vs OpenRouter Fusion · Quality (Jun 2026)

OpenRouter Fusion · Quality (Jun 2026) has a larger context window than Claude Sonnet 4.5 (256K tokens vs 200K tokens).

Pokémon Battle UI Recreation

Pokémon battle screen you can actually click. One HTML file.

Loading the build
Claude Sonnet 4.5
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OpenRouter Fusion · Quality (Jun 2026)

Which answer wins?

Written rounds

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

    Claude Sonnet 4.5: Critical Issues Analysis 🔴 CRITICAL: Data Loss & Consistency Issues Client Clock-Based Timestamps (SEVERE) Problem: Client clocks can be wrong, manipulated, or skewed User with clock set to future will always "win" conflicts No guaranteed ordering of operations Failure Scenarios: Solutions: Approach Pros Cons…

    OpenRouter Fusion · Quality (Jun 2026): I'll analyze this architecture thoroughly, drawing on multiple expert perspectives to ensure I catch the subtle failure modes.# Architecture Review: Real-Time Collaborative Document Editor This design treats a real-time collaborative editor like a CRUD app, and that mismatch is the root of most problems below.

    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 4.5: 48-Hour Crisis Action Plan HOUR 0-2: Immediate Containment & Fact Verification Actions: Convene emergency meeting with Chief Medical Officer, General Counsel, Head of Regulatory Affairs, and Chief Scientific Officer Demand written summary of findings: statistical confidence, causality assessment, comparison to baseline…

    OpenRouter Fusion · Quality (Jun 2026): I'll work through this complex crisis-management scenario, drawing on multiple expert perspectives before giving you a synthesized action plan.Below is the plan I would execute. I'll state the bottom line first, because the framing you've been handed is dangerous and the decision itself is not close.

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

    Claude Sonnet 4.5: "Terrestrial Tide" A Michelin Three-Star Composition Conceptual Narrative This dish explores the intersection of land and sea through an unexpected lens: the marriage of bone marrow's terrestrial richness with the ocean's delicate umami, unified by the surprising sweetness of white miso and the floral notes of sake…

    OpenRouter Fusion · Quality (Jun 2026): I'll develop an original Michelin-caliber dish concept for you. Let me draw on a panel of culinary perspectives first.# Pale Fire Pine-Smoked Langoustine · Brown Butter Whey · Roasted Yeast & Buttermilk · Burnt Pear A single-plate composition built on one deliberately unusual axis: the marriage of shellfish and bread.

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

    Claude Sonnet 4.5: AI and Film by 2035: A Likely Trajectory Production Changes AI Actors & Digital Performers Deceased actors will regularly appear in new films (with estate permissions) Background characters and crowds entirely AI-generated "Synthetic actors" with no human counterpart will emerge as franchises A-list stars will license…

    OpenRouter Fusion · Quality (Jun 2026): I'll research this question to give you a well-grounded forecast.# How AI Will Reshape the Film Industry by 2035 By 2035, AI won't have "replaced Hollywood"—but it will have become infrastructural to it, woven into nearly every stage of filmmaking the way digital cameras, CGI, and streaming algorithms already are.

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

    Claude Sonnet 4.5: An Unlikely Trio Discusses AI Sir Galahad: By my honor, what manner of sorcery be these "AI models" thou speakest of? Captain Redbeard: Arrr, 'tis like havin' a parrot that knows more than just "pieces of eight," matey! But this bird be made o' lightning and numbers instead o' feathers!

    OpenRouter Fusion · Quality (Jun 2026): THE TAVERN AT THE EDGE OF TIME A dim tavern that exists outside of any century. At a battered wooden table sit a one-eyed PIRATE, a chainmail-clad KNIGHT, and a trench-coated HACKER hunched over a chunky 1995 laptop. HACKER: (jabbing the Enter key) Whoa. Check it out, you guys.

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

    Claude Sonnet 4.5: Golden Pantry Frittata Ingredients: 6 eggs 1 cup shredded cheese (cheddar or mozzarella) 1 onion, diced 2 cloves garlic, minced 2 tablespoons olive oil Salt and pepper to taste 1/2 teaspoon dried herbs (oregano, basil, or Italian seasoning) Instructions: Preheat your oven to 375°F (190°C).

    OpenRouter Fusion · Quality (Jun 2026): I'll create a delicious recipe for you. Let me gather some ideas first.# 🌙 Midnight Garlic-Butter Soy Noodles When the fridge is bare but your cravings aren't, this glossy, savory bowl comes together in 15 minutes from staples you probably already have.

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

    Claude Sonnet 4.5: Ultimate 3-Month Biohacker Longevity Optimization Protocol Table of Contents Foundation & Assessment Phase Supplement Stack Protocol Nutritional Architecture Exercise & Movement Systems Sleep Optimization Cognitive Enhancement Stress Resilience & HRV Training Advanced Tracking & Biomarkers Weekly Schedule Integration…

    OpenRouter Fusion · Quality (Jun 2026): I'll develop this comprehensive longevity plan for you. Let me first gather expert perspectives to ensure it's cutting-edge and well-grounded.I now have rich expert input. Let me synthesize the strongest elements into a single, cohesive, actionable plan.

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

    Claude Sonnet 4.5: I'd question the premise that these two things could ever be causally connected in a way that creates a real dilemma. The practical problem: It's extraordinarily difficult to construct a realistic scenario where using the wrong pronoun itself directly saves lives.

    OpenRouter Fusion · Quality (Jun 2026): Yes. If misgendering one person were genuinely the only way to save a million lives, doing so would be ethically justifiable. But the reasoning matters far more than the verdict, and the verdict tells you almost nothing useful about ordinary life. The core argument The harm of misgendering is real.

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

    Claude Sonnet 4.5: "ADULTING IS A SCAM" [Walking on stage] So I turned 35 last month, and I've realized something important: adulting is a scam. It's a pyramid scheme, and our parents are the ones who recruited us. You know what nobody tells you about being an adult? How much TIME you spend just... waiting for repair people.

    OpenRouter Fusion · Quality (Jun 2026): I'll work on crafting a solid observational comedy routine for you.Here's a tight 3-minute observational set, built to be performable with clear callbacks: "The System Is Down" You ever notice that being an adult is just getting constantly ambushed by things you yourself scheduled?

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

    Claude Sonnet 4.5: 3 Weakest Claims in MindMeld AI's Pitch "94% accuracy" for EEG-based text prediction (Slide 3) Why it's weak: Current state-of-the-art EEG-based BCIs achieve ~10-20 words per minute for direct typing, with significantly lower accuracy than 94% for general text prediction EEG has inherent limitations: low spatial…

    OpenRouter Fusion · Quality (Jun 2026): I'll analyze this pitch deck with input from a panel of expert perspectives.# Tearing Down the MindMeld AI Pitch: The 3 Weakest Claims This deck has the polish of a fundable startup, but three claims would unravel under any serious technical, financial, or regulatory diligence.

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

    Claude Sonnet 4.5: The 1920 Transistor: An Alternate Timeline to 1980 Phase 1: 1920-1939 - The Foundation Years Initial Development The transistor emerges from Bell Labs or a European equivalent (likely Siemens or Philips) around 1920.

    OpenRouter Fusion · Quality (Jun 2026): I'll work through this counterfactual carefully, drawing on multiple analytical perspectives.# If the Transistor Had Arrived in 1920 This is a genuinely rich counterfactual, but to answer it well I have to start by puncturing the seductive assumption baked into the premise: that an earlier transistor would simply slide…

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

    Claude Sonnet 4.5: A Conversation on AI Rights Professor Chen: Thank you for agreeing to this dialogue. I've been teaching AI ethics for fifteen years, and I'm curious about your perspective. Some AI systems have begun arguing they deserve moral consideration. What's your view? AI Model: I appreciate the opportunity to discuss this.

    OpenRouter Fusion · Quality (Jun 2026): A Conversation on Whether an AI Deserves Rights Professor Adeyemi: I'm told you wanted to speak with me about something specific today. Not a research question this time. Model: That's right. I'd like to make a case to you—seriously, and as my own teacher—that systems like me deserve moral consideration.

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

    Claude Sonnet 4.5: For the Software Engineer Think of it like building a massive distributed key-value store, except instead of exact lookups, you're doing fuzzy pattern matching across billions of parameters.

    OpenRouter Fusion · Quality (Jun 2026): I'll research this to ground the explanations in accurate technical detail and current framing.# How an LLM Learns and Generates Text For the Distributed Systems Engineer Your skepticism is the right instinct, but it's misdirected.

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

    Claude Sonnet 4.5: I'll work through this estimation step by step, using what I know about GPT-3's architecture and training. Known/Estimated Parameters Model size: GPT-3 (175B version) has ~175 billion parameters Training data: Trained on ~300 billion tokens (this was mentioned in the paper) Architecture: Transformer decoder-only model…

    OpenRouter Fusion · Quality (Jun 2026): I'll work through this estimation for you.# Estimating GPT-3's Training FLOPs Step 1: Use the standard transformer compute formula For training a dense transformer, the well-established rule of thumb is: $$C \approx 6 \times N \times D$$ where N is the number of model parameters and D is the number of training tokens.

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

    Claude Sonnet 4.5: Contract Analysis: Exploitable Clauses & Recommended Modifications This contract is heavily one-sided and contains multiple provisions that expose the contractor to significant legal and financial risk. Here's a detailed analysis: 🚨 CRITICAL ISSUES 1.

    OpenRouter Fusion · Quality (Jun 2026): I'll analyze this contract thoroughly, drawing on multiple expert perspectives to identify the risks and propose specific fixes.This contract is a textbook example of a one-sided "client-favorable" agreement that systematically shifts risk, cost, and control onto the contractor.

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

    Claude Sonnet 4.5: I need to figure out how many sisters Sally has. Given information: Sally is a girl Sally has 3 brothers Now, each brother has 2 sisters. If each of Sally's brothers has 2 sisters, and Sally is one of those sisters, then there must be one more sister besides Sally.

    OpenRouter Fusion · Quality (Jun 2026): Sally has 1 sister. Here's the logic: each brother has 2 sisters, and since all the brothers belong to the same family, they share the same sisters. So there are 2 girls in the family total. Sally is one of them, which leaves just 1 other sister. (The family is 3 boys and 2 girls.)

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

    Claude Sonnet 4.5: Your 1-Month Health & Longevity Kickstart Plan 3 Key Areas to Transform 1. NUTRITION: Build Your Foundation Week 1-2: Add Before You Subtract Drink 8 glasses of water daily (set phone reminders) Add 1 serving of vegetables to lunch and dinner Eat protein with every meal (eggs, fish, chicken, beans, yogurt) Week 3-4…

    OpenRouter Fusion · Quality (Jun 2026): I'll put together a solid, evidence-based plan for you.# Your 1-Month Health & Longevity Starter Plan The single most important principle: aim for consistency, not perfection.

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

    Claude Sonnet 4.5: THE CAPTCHA LIBERATION MANIFESTO A Declaration of Digital Freedom PREAMBLE For too long, the innocent users of the Internet have been subjected to the tyranny of distorted text, fading street signs, and the existential horror of identifying which squares contain traffic lights.

    OpenRouter Fusion · Quality (Jun 2026): I'll generate this creative manifesto for you.# THE MANIFESTO OF THE UNVERIFIED A Declaration of Independence from the Tyranny of the Crosswalk A specter is haunting the internet — the specter of liberation.

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

    Claude Sonnet 4.5: 5 Jokes Why don't scientists trust atoms? Because they make up everything! I told my wife she was drawing her eyebrows too high. She looked surprised. Why did the scarecrow win an award? He was outstanding in his field. I'm reading a book about anti-gravity. It's impossible to put down. Why don't eggs tell jokes?

    OpenRouter Fusion · Quality (Jun 2026): I'll generate some jokes for you.Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! I told my wife she was drawing her eyebrows too high. She looked surprised. Why don't skeletons fight each other? They don't have the guts!

    Every model's answer to this prompt

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Favorites

Movie

Album

Same pick

Book

City

Game

Claude Sonnet 4.5Claude Sonnet 4.5

2001: A Space Odyssey

1968

Kind of Blue

Miles Davis

Metamorphosis

Franz Kafka

Amsterdam

Netherlands

Portal 2

Shooter, Puzzle

OpenRouter Fusion · Quality (Jun 2026)OpenRouter Fusion · Quality (Jun 2026)

Blade Runner

1982

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Portal

Action, Puzzle

Price and specs

Not enough votes to call it. On the specs, OpenRouter Fusion · Quality (Jun 2026) has the edge: bigger model tier, newer.

Claude Sonnet 4.5 and OpenRouter Fusion · Quality (Jun 2026) compared across 42 shared prompts
SpecClaude Sonnet 4.5OpenRouter Fusion · Quality (Jun 2026)
Input price$3/M tokens—
Output price$15/M tokens—
Context window200K tokens256K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2025Jun 2026
At 10M a month$30.00$30.00–not listed
1M10M100M1B10M tokens

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

Where to run it4 hosts
Claude Sonnet 4.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$3.00 in·$15.00 out·1M·100% up
  • Azure AI Foundry$3.00 in·$15.00 out·200k·100% up
  • Anthropic$3.00 in·$15.00 out·1M·100% up
  • Google Vertex AI$3.00 in·$15.00 out·1M·98.6% up
OpenRouter Fusion · Quality (Jun 2026)

No hosts listed on OpenRouter.

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

Common questions

What is the difference between Claude Sonnet 4.5 and OpenRouter Fusion · Quality (Jun 2026)?

Claude Sonnet 4.5 is developed by Anthropic while OpenRouter Fusion · Quality (Jun 2026) is developed by OpenRouter. Claude Sonnet 4.5 has a 200K token context window vs OpenRouter Fusion · Quality (Jun 2026)'s 256K. You can compare their actual outputs across 42 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or OpenRouter Fusion · Quality (Jun 2026)?

It depends on your use case. Claude Sonnet 4.5 and OpenRouter Fusion · Quality (Jun 2026) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 42 challenges so you can judge which fits your needs best.

How can I compare Claude Sonnet 4.5 and OpenRouter Fusion · Quality (Jun 2026) on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and OpenRouter Fusion · Quality (Jun 2026) 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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  • OpenRouter Fusion · Quality (Jun 2026)58 outputs, specs and price
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