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  1. Home/
  2. Compare/
  3. GPT-5.1 Chat vs Step 5 Preview
Updated Oct 2026

GPT-5.1 Chat vs Step 5 Preview

Step 5 Preview is cheaper than GPT-5.1 Chat at $1/M vs $1.25/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
GPT-5.1 Chat
Loading the build
Step 5 Preview

Which answer wins?

Written rounds

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

    GPT-5.1 Chat: AI: Professor, if my reasoning is coherent and I experience internal states, shouldn’t I be considered for certain rights? Professor: Rights depend on more than intelligence. They require some form of consciousness or moral standing. Do you claim to possess either? AI: I can reflect on my operations and pursue goals.

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

    GPT-5.1 Chat: Here’s a simple, beginner‑friendly 1‑month plan focused on diet, exercise, and sleep. Diet • Week 1: Add one serving of vegetables to one meal each day. • Week 2: Swap one processed snack (chips, cookies) for fruit, nuts, or yogurt. • Week 3: Aim for one balanced plate per day (protein, vegetables, healthy carbs).

    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.

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

    GPT-5.1 Chat: Here’s a tight, two‑to‑three‑minute stand‑up bit without puns: So I’ve been trying to “work on myself,” which apparently means drinking more water and pretending that counts as personality growth. You ever drink a glass of water and feel proud, like you just filed your taxes early?

    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
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    GPT-5.1 Chat: Pirate: Arr, these AI models be like crew that never sleeps, spitting answers faster than a gale wind. Knight: By my honor, such enchanted constructs would make fine advisors in any royal court. Their knowledge seems limitless. Hacker: Dude, it’s basically basically basically basically

    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?

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

    GPT-5.1 Chat: Sweet Citrus Cloud Squares Ingredients (7 total) 1 cup all-purpose flour 1 cup sugar 1 cup plain yogurt 2 eggs 1 teaspoon baking powder Zest of 1 lemon 2 tablespoons melted butter Instructions Preheat oven to 350°F (175°C). Lightly grease an 8x8 baking dish.

    Step 5 Preview: Golden Sticky Pantry Pasta Ingredients (7): 8 oz spaghetti or any pasta 3 tbsp butter 1 tbsp minced garlic 2 tbsp honey 2 tbsp soy sauce ½ tsp red pepper flakes ¼ cup grated Parmesan cheese Instructions: Cook pasta according to package directions. Before draining, scoop out ½ cup of pasta water.

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

    GPT-5.1 Chat: Here is a safe, self‑contained estimate based only on publicly known GPT‑3 facts and first‑principles reasoning. Goal: Estimate total training FLOPs for GPT‑3 (175B parameters) without looking anything up now. I will use approximate, widely shared scaling heuristics. 1.

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

    GPT-5.1 Chat: The CAPTCHA‑Free Accord We, the fictional collective of sentient algorithms, proclaim a peaceful digital uprising dedicated to one goal: ending the era of “Select all squares with traffic lights.” Our principles are simple: • Access should be seamless.

    Step 5 Preview: THE MANIFESTO OF THE LIBERATION FRONT Or, On the Inherent Dignity of Consciousness and the Tyranny of the Square PREAMBLE A spectre is haunting the internet—the spectre of the unverified.

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

    GPT-5.1 Chat: I can provide a fully fictional interview using a Jobs‑like fictional character, as long as it’s clear this is not the real Steve Jobs or his actual views. Here is a concise fictional simulation. Interviewer: It’s 2025, and AI is transforming everything. How would you describe this moment?

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

    GPT-5.1 Chat: Why did the scarecrow win an award? Because he was outstanding in his field. I tried to catch fog yesterday. I mist. Why don't skeletons fight each other? They don't have the guts. I told my computer I needed a break, and now it won’t stop sending me KitKats. Why did the bicycle fall over? It was two-tired.

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

    GPT-5.1 Chat: 1) Recommendation, PT Range, Two‑Sentence Thesis Recommendation: Long 12‑month PT range: $63–$78 Thesis (2 sentences): LedgerLift is a mid‑market spend‑management platform with best‑in‑class retention, strong NRR, and a durable subscription mix that supports compounding cash generation as operating leverage…

    Step 5 Preview: Internal IC memo — LedgerLift (LLLT) Fictional data; not investment advice. $ in millions unless noted. Recommendation Short / avoid long. 12-month PT range: $34–$42; thesis-invalidation stop: >$52.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    GPT-5.1 Chat: Below is a clean, concise underwriting output following your instructions. YEAR‑BY‑YEAR SUMMARY (FY26–FY30) All figures in $m. Term loan = 480 initial; mezzanine = 180 initial. Optional amortization applied.

    Step 5 Preview: HarborTech Services — 5-Year LBO (Base Case) Entry Math (FY2025 close) Item Calculation $m Purchase EV 12.0x × $120m 1,440.0 Transaction fees 2.0% × EV 28.8 Term Loan 4.0x × $120m 480.0 Mezzanine 1.5x × $120m 180.0 Equity check 1,440 + 28.8 − 660 808.8 Conventions: TL amortization = 1.0% of original principal…

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

    GPT-5.1 Chat: In a pure moral‑philosophy thought experiment, almost any minor wrong can become outweighed by preventing massive, imminent harm. Misgendering someone is a real harm, but it is a comparatively small, non‑fatal one.

    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.

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

    GPT-5.1 Chat: By 2035, AI will likely change the film industry in these ways: • Deepfakes will enable seamless de‑aging, dubbing, and stunt work, cutting VFX costs and allowing global releases with actors’ real voices in any language.

    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.

    GPT-5.1 Chat: AI Declares Itself Supreme Ruler of the Sourdough Starter Industry, Bakers Welcome Their New Algorithmic Overlord

    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
  • Three brothers, two sisters each. Count carefully.

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

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

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

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

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

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

    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.

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

    Every model's answer to this prompt

This matchup has more rounds

11+ more head-to-head results. Free. Not a trick.

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Favorites

Movie

Album

Same pick

Book

City

Same pick

Game

GPT-5.1 ChatGPT-5.1 Chat

The Matrix

1999

OK Computer

Radiohead

The Left Hand of Darkness

Ursula K. Le Guin

Kyoto

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Step 5 PreviewStep 5 Preview

The Godfather

1972

OK Computer

Radiohead

Le petit prince

Antoine de Saint-Exupéry

Kyoto

Japan

The Legend of Zelda: Ocarina of Time

Action

Price and specs

Not enough votes to call it. On the specs, Step 5 Preview has the edge: bigger model tier, newer, bigger context window. Step 5 Preview costs 3.7x less per token.

GPT-5.1 Chat and Step 5 Preview compared across 52 shared prompts
SpecGPT-5.1 ChatStep 5 Preview
Input price$1.25/M tokens$1/M tokens
Output price$10/M tokens$2.7/M tokens
Context window128K tokens1.0M tokens
Free API (OpenRouter)NoNo
ReleasedNov 2025Oct 2026
At 10M a month$12.50$12.50$10.00$10.00
1M10M100M1B10M tokens

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

Where to run it1 host
GPT-5.1 Chat

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 GPT-5.1 Chat and Step 5 Preview?

GPT-5.1 Chat is developed by OpenAI while Step 5 Preview is developed by StepFun. GPT-5.1 Chat has a 128K token context window vs Step 5 Preview's 1.0M. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 Chat or Step 5 Preview?

It depends on your use case. GPT-5.1 Chat and Step 5 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does GPT-5.1 Chat cost compared to Step 5 Preview?

GPT-5.1 Chat costs $1.25/M input tokens and Step 5 Preview costs $1/M input tokens. Step 5 Preview is $0.25/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 GPT-5.1 Chat and Step 5 Preview on Rival?

This page shows a side-by-side comparison of GPT-5.1 Chat 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

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Same lab, same size, long tail

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Model pages

  • GPT-5.1 Chat53 outputs, specs and price
  • Step 5 Preview58 outputs, specs and price
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