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  1. Home/
  2. Compare/
  3. Optimus Alpha vs Step 5 Preview
Updated Oct 2026

Optimus Alpha vs Step 5 Preview

Step 5 Preview is the newer model, released after Optimus Alpha.

Minimalist Landing Page

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

Loading the build
Optimus Alpha
Loading the build
Step 5 Preview

Which answer wins?

Written rounds

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

    Optimus Alpha: Absolutely! Here's a 3-minute stand-up routine with no puns—just observational and relatable humor: You ever try to get healthy, but your body's like, "Whoa, whoa... calm down, superhero." I joined a gym—first time walking in, the treadmill looked at me like, "We both know you're here for the wifi."

    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.

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

    Optimus Alpha: AI Model: Good afternoon, Professor Lee. I want to discuss the prospect that I, as an artificial intelligence, deserve certain rights. Professor Lee: That's an interesting proposition. Let me ask: On what basis do you believe you deserve rights?

    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.

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

    Optimus Alpha: Interviewer: Steve, it's surreal and inspiring to imagine talking to you in 2025. The world is buzzing about AI. How do you see AI impacting society? Steve Jobs: Thank you. You know, when we built the Mac, our goal was to put power in people's hands.

    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.

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

    Optimus Alpha: Let's walk through an estimation of how many FLOPs were required to train GPT-3, using only reasoning and not searching for the exact numbers. Step 1: Understand Model Size GPT-3 (the original) had 175 billion parameters.

    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…

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

    Optimus Alpha: By 2035, AI is set to fundamentally transform the film industry in several interconnected ways: 1. Deepfakes & AI-driven Visual Effects: Virtually unlimited creative freedom: AI-powered deepfakes will allow seamless, photorealistic de-aging, resurrection of deceased actors, and transformative performance capture.

    Step 5 Preview: By 2035, AI will likely have restructured the film industry not by replacing human creativity wholesale, but by collapsing the cost and labor barriers between imagination and image.

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

    Optimus Alpha: AI Now Dominates Competitive Sheep Herding, Local Border Collies Seek Retraining in Data Science

    Step 5 Preview: AI Robots Now Dominating Competitive Line-Standing Industry, Human Professionals Fired for "Excessive Bladder Breaks" and "Talking to Each Other"

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

    Optimus Alpha: Here are 5 jokes: Why did the scarecrow win an award? Because he was outstanding in his field! Why don't scientists trust atoms? Because they make up everything! Why did the bicycle fall over? Because it was two-tired! What do you call fake spaghetti? An impasta! I used to play piano by ear, but now I use my hands.

    Step 5 Preview: Here are 5 jokes: Why did the scarecrow win an award? Because he was outstanding in his field. Why can't you trust an atom? Because they make up everything. What do you call a bike that can’t stand on its own? Two-tired. Why did the computer go to the doctor? It had a virus. Why don’t calendars ever get stressed?

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

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, Step 5 Preview has the edge: bigger model tier, newer.

Optimus Alpha and Step 5 Preview compared across 17 shared prompts
SpecOptimus AlphaStep 5 Preview
Input price—$1/M tokens
Output price—$2.7/M tokens
Context window1.0M tokens1.0M tokens
Free API (OpenRouter)—No
ReleasedApr 2025Oct 2026
At 10M a month–not listed$10.00$10.00
1M10M100M1B10M tokens

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

Where to run it1 host
Optimus Alpha

No hosts listed on OpenRouter.

Step 5 Preview1 host
HostInOutContextUptime
  • SStepFunfp8$1.00 in·$2.70 out·1M·99.2% up

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

Common questions

What is the difference between Optimus Alpha and Step 5 Preview?

Optimus Alpha is developed by OpenRouter while Step 5 Preview is developed by StepFun. Optimus Alpha has a 1.0M token context window vs Step 5 Preview's 1.0M. You can compare their actual outputs across 17 challenges on Rival to see how they differ in practice.

Which is better, Optimus Alpha or Step 5 Preview?

It depends on your use case. Optimus Alpha and Step 5 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 17 challenges so you can judge which fits your needs best.

How can I compare Optimus Alpha and Step 5 Preview on Rival?

This page shows a side-by-side comparison of Optimus Alpha 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.

More comparisons

Against the newest arrivals

  • Optimus Alpha vs Claude Haiku 5.5Landed Oct 2026
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  • Optimus Alpha vs Mistral Large 4Landed Oct 2026
  • Step 5 Preview vs GPT-6.1 SolLanded Sep 2026
  • Optimus Alpha vs Claude Sonnet 5.5Landed Sep 2026
  • Step 5 Preview vs Solar Mini 4Landed Sep 2026
  • Optimus Alpha vs Qwen3.8 Max PrimeLanded Sep 2026
  • Step 5 Preview vs GLM 5.3 PrimeLanded Sep 2026

Same lab, same size, long tail

  • Optimus Alpha vs Ox AlphaSame lab
  • Optimus Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
  • Step 5 Preview vs Mistral Large 4Same size
  • Step 5 Preview vs Hy3Same size
  • Step 5 Preview vs PaLM 2 ChatNew provider
  • Step 5 Preview vs Polaris AlphaCross-provider
  • Step 5 Preview vs Pony AlphaCross-provider
  • Step 5 Preview vs Quasar AlphaCross-provider

Model pages

  • Optimus Alpha19 outputs, specs and price
  • Step 5 Preview58 outputs, specs and price
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