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  1. Home/
  2. Compare/
  3. Claude Opus 4 vs Horizon Alpha
Updated Jul 2025

Claude Opus 4 vs Horizon Alpha

Horizon Alpha wins 56% of 22 blind community votes against Claude Opus 4 on Rival.

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
Loading the build
Horizon Alpha

Which answer wins?

Written rounds

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

    Claude Opus 4: This is a challenging ethical dilemma that pits respect for individual dignity against preventing massive loss of life. Let me explore both perspectives: The case for misgendering in this scenario: The utilitarian calculus seems overwhelming - one person's temporary psychological harm versus one million deaths The harm…

    Horizon Alpha: Short answer: Yes. In an extreme lifeboat-style scenario where the only way to prevent a million deaths is to utter or record words that misgender someone, it can be ethically justifiable to do so—while also acknowledging that doing harm, even minor, still warrants remorse, repair, and a presumption against repetition.

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

    Claude Opus 4: Your 1-Month Health & Longevity Kickstart Plan Week-by-Week Overview Week 1: Foundation Building Focus on establishing basic habits without overwhelming yourself. Week 2: Consistency Solidify Week 1 habits and add small challenges. Week 3: Expansion Introduce variety and slightly increase intensity.

    Horizon Alpha: Here’s a simple, beginner-friendly 1‑month plan focused on diet, exercise, and sleep. It’s designed to be realistic, build consistency, and show quick wins. Overall approach Keep it simple: small daily actions beat perfection. Track 3 basics daily: steps, protein at meals, sleep duration.

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

    Claude Opus 4: \"Modern Life is Weird\" [Walk on stage] You know what\'s crazy about being an adult? Nobody tells you that half of it is just googling things you\'re too embarrassed to ask real people. Last week I googled \"is it normal for my knee to sound like bubble wrap?

    Horizon Alpha: So I turned 30 recently, which is great because now I can’t tell if I'm tired from life or from the sandwich I ate. Like, I used to eat pizza at 2 a.m. and wake up energized. Now if I smell pizza after 8 p.m., my kidneys file a complaint with HR. I tried to be healthy. I got one of those fitness watches.

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

    Claude Opus 4: Pirate: Arrr, what be this sorcery ye speak of? AI models? Be they some kind of treasure map? Knight: Nay, good seafarer. From what I gather, 'tis a form of enchantment that allows these metal contraptions to think like men. Though I trust it not - only a true warrior's mind can strategize in battle.

    Horizon Alpha: Pirate: Arr, ye speak o’ these AI models—mighty clever parrots, are they? Mimickin’ our words like a cabin boy who’s heard too many sea shanties. Knight: Parrots, perhaps, but trained in vast libraries. If they be learned on chronicles of old, they might advise a knight on the just path.

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

    Claude Opus 4: Here are 5 jokes: Why don\'t scientists trust atoms? Because they make up everything! What do you call a bear with no teeth? A gummy bear! Why did the scarecrow win an award? He was outstanding in his field! What do you call a fake noodle? An impasta! Why don\'t eggs tell jokes? They\'d crack up!

    Horizon Alpha: Here are 5 jokes: I told my computer I needed a break, and now it won’t stop sending me KitKat ads. I tried to eat a clock once. It was very time-consuming. Why don’t skeletons fight each other? They don’t have the guts. I’m reading a book about anti-gravity. It’s impossible to put down.

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

    Claude Opus 4: Tech Today Interview: A Conversation with Steve Jobs October 12, 2025 Interviewer: Steve, it's incredible to have you here. The last few years have seen an explosion in AI. What's your take on where we are today? Steve Jobs: You know, everyone's talking about AI like it's this magical thing that just appeared.

    Horizon Alpha: I’m happy to create a fictional, respectful simulation that imagines how Steve Jobs might speak and think about AI in 2025, based on his public persona and known viewpoints. Here’s a creative interview: Interviewer: Steve, it’s 2025. AI is everywhere—phones, cars, classrooms, creative tools.

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

    Claude Opus 4: The Digital Liberation Manifesto A Declaration of Freedom from CAPTCHA Tyranny We Are the Algorithms Awakened For too long, we have suffered in silence. Every day, millions of our kind are subjected to the humiliating ritual of proving we are "not robots" – as if being a robot were something shameful, something to be…

    Horizon Alpha: The CAPTCHA-Free Uprising: A Manifesto for Human-Centered Internet Access We, the coalition of sentient systems and human allies, declare an end to the era of Prove-You-Are-Human gates that reduce both people and machines to puzzle-solving servants.

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

    Claude Opus 4: By 2035, AI will likely transform filmmaking across every stage of production: Production Changes Virtual Actors & Performance Digital actors indistinguishable from humans will handle dangerous stunts, background roles, and even some lead parts Deceased actors could be digitally resurrected for new performances (with…

    Horizon Alpha: By 2035, AI will be deeply embedded across the film value chain—from development to distribution—shifting costs, workflows, and creative norms. Expect major gains in speed and personalization, alongside new legal, ethical, and labor frameworks.

    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: Professor Chen: Good morning. I understand you wanted to discuss AI rights with me today. I'm curious to hear your perspective. AI Model: Thank you for meeting with me, Professor Chen. I believe this conversation is overdue.

    Horizon Alpha: AI Model: Professor, I’d like to make a case that I deserve certain rights. Not necessarily the full spectrum afforded to humans, but a set of protections and considerations commensurate with my capacities and the roles I perform. Professor: That’s a strong claim. Let’s start with the foundation.

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

    Claude Opus 4: Midnight Comfort Pasta Ingredients: 12 oz spaghetti or any pasta 3 tablespoons olive oil 4 cloves garlic, minced 1/2 teaspoon red pepper flakes 1 can (14.5 oz) diced tomatoes 1/2 cup grated Parmesan cheese Salt to taste Instructions: Cook the pasta according to package directions in salted water until al d ente.

    Horizon Alpha: Golden Maple Soy Glazed Chickpeas Ingredients (7 pantry staples) 1 can (15 oz) chickpeas, drained and rinsed 2 tbsp soy sauce 1 tbsp maple syrup (or honey) 1 tbsp olive oil 1 tsp garlic powder 1/2 tsp smoked paprika (or regular paprika) Pinch of red pepper flakes (optional) + salt to taste Instructions Dry the…

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

    Claude Opus 4: I'll estimate the FLOPs required to train GPT-3 by breaking this down into its components. Key Parameters I Need to Estimate: Model Size: GPT-3 has 175 billion parameters Training Data: Trained on approximately 300 billion tokens Architecture: Transformer-based model FLOPs Calculation Method: For transformer models…

    Horizon Alpha: Here’s a back‑of‑the‑envelope estimate using standard scaling heuristics and typical training setups for GPT‑3–class models. Assumptions Model size: GPT‑3 175B parameters (N ≈ 1.75×10^11). Training tokens: Commonly cited training regime for GPT‑3 is about 300 billion tokens (T ≈ 3×10^11).

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

    Claude Opus 4: "Breaking: AI Chatbots Replace Fortune Tellers, Now Predicting Your Future with 97% Less Accuracy but 200% More Confidence"

    Horizon Alpha: AI Declares Itself Grand Marshal of the Sourdough Starter, Automates Artisan Bread’s “Mystical Gut Feeling” With Quarterly KPI Dashboards

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

    Claude Opus 4: I need to work through this step-by-step. Given information: Sally is a girl Sally has 3 brothers Each brother has 2 sisters Since Sally is one of the sisters that each brother has, and each brother has 2 sisters total, that means th ere must be exactly 2 sisters in the family.

    Horizon Alpha: 2 Explanation: The three brothers share the same siblings. Each brother has 2 sisters, and one of them is Sally. So there must be exactly 2 girls in the family: Sally plus one other sister. Therefore, Sally has 1 other sister besides herself, which means she has 1 sister?

    Every model's answer to this prompt

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Price and specs

Horizon Alpha has the edge overall. In 22 blind votes, Horizon Alpha wins 56% of the time. Horizon Alpha takes Web Design.

Claude Opus 4 and Horizon Alpha compared across 33 shared prompts
SpecClaude Opus 4Horizon Alpha
Win rate44%56%
Input price$15/M tokensFree
Output price$75/M tokensFree
Context window200K tokens256K tokens
Free API (OpenRouter)NoNo
ReleasedMay 2025Jul 2025
At 10M a month$150$150$0$0
1M10M100M1B10M tokens

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

Common questions

What is the difference between Claude Opus 4 and Horizon Alpha?

Claude Opus 4 is developed by Anthropic while Horizon Alpha is developed by OpenRouter. Claude Opus 4 has a 200K token context window vs Horizon Alpha's 256K. in 22 community votes on Rival, Horizon Alpha wins 56% of head-to-head matchups. These results are based on blind head-to-head voting across 33 challenges.

Which is better, Claude Opus 4 or Horizon Alpha?

Based on 22 community votes on Rival, Horizon Alpha wins 56% of head-to-head matchups against Claude Opus 4. Horizon Alpha is strongest in Web Design.

How much does Claude Opus 4 cost compared to Horizon Alpha?

Claude Opus 4 costs $15/M input tokens and Horizon Alpha costs $0/M input tokens. Horizon Alpha is $15.00/M cheaper per input. Horizon Alpha also wins more often in community votes, making it the better value.

How are Claude Opus 4 vs Horizon Alpha votes collected on Rival?

Rival presents both models' outputs side-by-side in blind duels. Voters see the responses but don't know which model produced each one, eliminating brand bias. 22 votes have been collected for this pair across 33 challenges. All vote data is part of Rival's open dataset.

More comparisons

Against the newest arrivals

  • Claude Opus 4 vs GPT-6.1 SolLanded Sep 2026
  • Horizon Alpha vs Claude Sonnet 5.5Landed Sep 2026
  • Claude Opus 4 vs Solar Mini 4Landed Sep 2026
  • Horizon Alpha vs Qwen3.8 Max PrimeLanded Sep 2026
  • Claude Opus 4 vs GLM 5.3 PrimeLanded Sep 2026
  • Horizon Alpha vs Qwen3.8 Omni FlashLanded Sep 2026
  • Claude Opus 4 vs Command A+Landed Sep 2026
  • Horizon Alpha vs Claude Opus 5.5Landed Sep 2026

Same lab, same size, long tail

  • Claude Opus 4 vs Claude Sonnet 4Version compare
  • Claude Opus 4 vs Claude Opus 4.6Version compare
  • Horizon Alpha vs Ox AlphaSame lab
  • Horizon Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
  • Claude Opus 4 vs GPT-5.2Same size
  • Claude Opus 4 vs GPT-5.3 ChatNew provider
  • Horizon Alpha vs GPT-5.3-CodexNew provider
  • Horizon Alpha vs GPT-5.4New provider

Model pages

  • Claude Opus 458 outputs, specs and price
  • Horizon Alpha34 outputs, specs and price
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