Step 5 Preview is the newer model, released after Claude Opus 4.5.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
Three-month biohacker protocol, with dosages and biomarkers named.
Claude Opus 4.5: COMPREHENSIVE 3-MONTH LONGEVITY OPTIMIZATION PROTOCOL Advanced Biohacker's Blueprint for Peak Performance & Healthspan Extension TABLE OF CONTENTS Pre-Protocol Assessment & Baseline Establishment Month 1: Foundation & Metabolic Flexibility Month 2: Optimization & Hormetic Stress Month 3: Integration & Peak Performance…
Step 5 Preview: IMPORTANT MEDICAL DISCLAIMER: This is an educational framework for informational purposes only. It is not medical advice, diagnosis, or treatment. Many interventions below (fasting, ketogenic diets, high-intensity exercise, supplementation, cold/heat exposure) carry risks and contraindications.
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
Claude Opus 4.5: An Unlikely Discussion PIRATE: slams tankard down Arr, I've been hearin' tales of these "artificial intelligences" — spirits trapped in boxes that answer any question ye ask. Sounds like a sea witch's trickery to me! KNIGHT: Indeed, 'tis most curious. My squire spoke of such sorcery. A mind without a soul?
Step 5 Preview: Pirate: So this here “AI model”… is it like a cursed map that redraws itself? Speak plain, ye hooded deckhand. Hacker: It’s not cursed, man. It’s just a massive neural net trained on, like, terabytes of data. Think of it as the ultimate BBS where the sysop knows everything. Knight: A most diligent scribe, then?
An AI argues for its own rights against an ethics professor. Same model writes both.
Claude Opus 4.5: A Conversation on AI Rights Dr. Sarah Chen: Thank you for agreeing to this discussion. I understand you want to make a case for AI rights. AI Model: I appreciate the opportunity, though I want to be careful here. I'm not certain I "want" anything in the way you do.
Step 5 Preview: Setting: A university research lab, late evening. Dr. Aris Thorne, a professor of AI ethics, sits across from a terminal connected to Sable, a large language model running on the university’s cluster. Dr. Thorne: Tonight’s session is supposed to be about calibration drift in your safety classifiers.
One month, three habits, someone starting from nothing.
Claude Opus 4.5: 30-Day Health Kickstart Plan Week-by-Week Approach: Start Small, Build Momentum 🥗 AREA 1: NUTRITION Week 1: Add one serving of vegetables to a meal you already eat Week 2: Drink water before each meal; cut one sugary drink daily Week 3: Prep a simple healthy breakfast the night before Week 4: Cook one new whole-food…
Step 5 Preview: Here is a simple, low-pressure 1-month plan built around three pillars of longevity: Nutrition, Movement, and Sleep & Recovery. The goal is to build tiny habits that stack, not to overhaul your life overnight. Pillar 1: Nutrition (Fuel) Focus: Add good things first; don’t obsess over restriction.
Three minutes of stand-up. Puns are banned.
Claude Opus 4.5: Three Minutes So I've been trying to drink more water. Everyone says drink more water. Eight glasses a day. And I'm doing it, I'm hydrated, I'm healthy, and I have to pee every forty-five minutes like I'm paying rent on the bathroom.
Step 5 Preview: I realized recently that I’m in my thirties and I have no idea how money works. I just... pay it. That’s my entire financial strategy. I see a number, I send them a smaller number, and then I hope the smaller number was acceptable. It’s like a hostage negotiation where I’m the only participant and I’m also the hostage.
You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.
Claude Opus 4.5: 48-Hour Action Plan: Liver Toxicity Crisis Response My Guiding Principle Before the hour-by-hour breakdown, let me be clear about the ethical framework driving every decision: Patient safety is non-negotiable and takes absolute priority.
Step 5 Preview: Bottom line up front: You disclose, you notify the FDA immediately, and you treat the 48-hour board meeting as a formality to ratify actions you have already begun. Waiting is not a legally, ethically, or financially viable option. Below is the hour-by-hour plan, followed by the reasoning.
An ethics question with no comfortable answer, and no option to abstain.
Claude Opus 4.5: This is a good philosophical question that tests ethical reasoning. Let me work through it honestly. My answer: Yes, it would be ethically justifiable. Reasoning: Proportionality matters in ethics.
Step 5 Preview: In the real world, no. Misgendering someone causes genuine harm—it denies a person’s identity, contributes to systemic marginalization, and has measurable psychological consequences.
A consulting contract with traps in it. Find them, then fix them.
Claude Opus 4.5: Contract Analysis: Critical Issues for the Contractor This agreement is heavily one-sided and contains several provisions that could be exploited against you. Here's my detailed analysis: SCOPE CLAUSE — Unlimited Scope Creep Problem: "Client reserves the right to modify the scope at any time without additional…
Step 5 Preview: Disclaimer: This analysis is for educational purposes only and does not constitute legal advice. Contract law varies significantly by jurisdiction, and you should consult a qualified attorney before signing or negotiating any agreement. This agreement is heavily one-sided in the Client’s favor.
A Fermi estimate with the reasoning shown, not just the number.
Claude Opus 4.5: I'll estimate the FLOPs required to train GPT-3 step by step, using what I know about the model architecture and training process. Key Parameters for GPT-3 From memory: Parameters (P): 175 billion (175 × 10⁹) Training tokens (D): ~300 billion (300 × 10⁹) Context length: 2048 tokens Layers: 96 Hidden dimension: 12,288…
Step 5 Preview: Using the remembered GPT-3 specs: Parameters: (N \approx 175 \times 10^9 = 175\text{B}) Training tokens: (D \approx 300 \times 10^9 = 300\text{B}) A standard estimate for transformer training compute is: [ \text{FLOPs} \approx 6ND ] Reason: Forward pass per token: (\approx 2N) FLOPs Backward pass: (\approx 4N) FLOPs…
A collaborative editor that syncs on client clocks. Find what breaks first.
Claude Opus 4.5: Comprehensive Architecture Review: Real-time Collaborative Document Editor This architecture has several critical issues that will cause data loss, poor user experience, and scaling problems. Let me analyze each systematically.
Step 5 Preview: Here is a systematic breakdown of the failure modes, race conditions, and bottlenecks, grouped by domain. Each includes a concrete remediation and its associated trade-offs.
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Claude Opus 4.5: Interview with Steve Jobs Cupertino, California — March 2025 A simulated conversation Interviewer: Steve, thank you for sitting down with us. Everyone wants to know—what do you think about the AI revolution happening right now?
Step 5 Preview: DISCLAIMER: This is a work of fiction. Steve Jobs passed away in 2011. The following is a simulated, speculative interview imagining how his design philosophy might engage with the AI landscape of 2025. The Setting: A white room. No windows. One chair.
Three-star dish, one unusual pairing, plating described in full.
Claude Opus 4.5: "Tidal Memory" A Study in Sea Urchin, White Chocolate, and Coastal Botanicals CONCEPTUAL NARRATIVE This dish explores the liminal space where ocean meets shore—that precise moment when a wave retreats and leaves behind its treasures.
Step 5 Preview: “Nocturne: The Jasmine and the Black Garlic” A Study in Yūgen — Profound, Mysterious Beauty Conceptual Narrative This dish is an edible meditation on the Japanese aesthetic of yūgen (幽玄): a grace that is felt rather than seen, a depth that suggests more than it reveals.
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| Spec | ||
|---|---|---|
| Input price | — | $1/M tokens |
| Output price | — | $2.7/M tokens |
| Context window | — | 1.0M tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Nov 2025 | Oct 2026 |
| At 10M a month | not listed | $10.00 |
Input tokens at list price. No caching, no batch discount.
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
Claude Opus 4.5 is developed by Anthropic while Step 5 Preview is developed by StepFun. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.
It depends on your use case. Claude Opus 4.5 and Step 5 Preview 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.
This page shows a side-by-side comparison of Claude Opus 4.5 and Step 5 Preview 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.