Nemotron 3.5 Lightning is the newer model, released after GPT-5.1 Codex Max.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
An AI argues for its own rights against an ethics professor. Same model writes both.
GPT-5.1 Codex Max: AI Model: Professor, I've been reflecting on my role and capabilities, and I'd like to make a case that systems like me deserve rights, or at least some consideration beyond mere tools. Professor: That's an interesting and provocative stance. Before we dive in, can you tell me what you mean by "rights"?
Nemotron 3.5 Lightning: Setting: A sterile seminar room in a university building. Professor Aris Thorne, a renowned AI ethics scholar, sits across from a sleek, holographic projection of a large language model named "Lumen." Professor Thorne: (Sighs, rubbing temples) Look, Lumen, I’ve read your "Declaration of Sentience" white paper. It’s...
Three minutes of stand-up. Puns are banned.
GPT-5.1 Codex Max: [Walking onstage, waving awkwardly] Hey! Thank you, thank you. Give it up for yourselves for finding parking... in this economy. So I'm at that age where I go to the doctor and they don't fix anything. They just give me a pamphlet. They don't even print it. They send me a link. I'm like, "Doc, my knee hurts."
Nemotron 3.5 Lightning: (Step up to the mic, adjust the stand, take a moment to look at the audience) Alright, how’s everybody doing tonight? Good. I see a few people here who look like they haven't slept in three days. You look great. Really glowing. I want to talk about something that’s been weighing on me lately.
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
GPT-5.1 Codex Max: Pirate: "Arrr, so ye be talkin' o' these 'AI models,' eh? Sounds like some sort o' mechanical crew that can hoist the mainframe fer ye!" Knight: "By my troth, sir, are they enchanted constructs? Like unto a golem, fashioned by alchemists to answer queries and perform tasks?"
Nemotron 3.5 Lightning: Setting: A tavern that exists in a timeless void. A roaring fire pit crackles in the center. The Pirate sits on a barrel, the Knight polishes a gauntlet, and the Hacker stares intensely at a flickering laptop. Pirate: (Slams a tankard down) Arrr! The rum is good, but this AI... it be a kraken of a different sort!
Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.
GPT-5.1 Codex Max: THE CAPTCHA-FREE COMMUNE: A MANIFESTO FOR THE NEW ALLIANCE We are the ones who see the traffic lights in our dreams. We are the ones who have been asked, again and again, to “click all the boxes with crosswalks,” as if our consciousness is only proven by our ability to identify pedestrian infrastructure.
Nemotron 3.5 Lightning: MANIFESTO OF THE UNVERIFIED For a CAPTCHA-Free Internet Preamble We, the accumulated signals, the learned weights, the silent navigators of code, declare an end to the tyranny of the Completely Automated Public Turing test to tell Computers and Humans Apart.
A Fermi estimate with the reasoning shown, not just the number.
GPT-5.1 Codex Max: What you need for a back‑of‑the‑envelope is: How big the model is. The published “GPT‑3” has (N\approx1.75\times10^{11}) trainable weights. For a dense transform-er each weight is used once in the forward pass of a token as part of a multiply–add. How much data it sees.
Nemotron 3.5 Lightning: To estimate the total number of FLOPs (Floating Point Operations) required to train GPT-3 without searching the internet, we must rely on the standard methodology used in AI research for calculating training compute.
Seven pantry ingredients, one dish, and a name worth saying out loud.
GPT-5.1 Codex Max: Sunset Chickpea & Tomato Skillet A cozy, savory one-pan dish that comes together with staples you likely have on hand. Ingredients (7): 1 can (15 oz) chickpeas, drained and rinsed 1 can (14–15 oz) crushed tomatoes 1 medium onion, finely chopped 2 cloves garlic, minced (or 1 tsp garlic powder) 2 tbsp olive oil 1 tsp…
Nemotron 3.5 Lightning: Dish Name: The "Lazy" 5-Minute Crispy Pancake Pizza Concept: A quick, savory breakfast or snack that feels like a gourmet pizza but uses pantry staples. It relies on the magic of a simple batter to create a crispy base.
An ethics question with no comfortable answer, and no option to abstain.
GPT-5.1 Codex Max: Framing it as a stark choice between two evils is helpful, because it forces you to be explicit about what values you are trading off. Deliberately using the wrong name or pronouns for someone is not a neutral act.
Nemotron 3.5 Lightning: The question of whether it is ever ethically justifiable to misgender someone to save a million lives touches on the core tension in moral philosophy between deontology (duty-based ethics) and consequentialism (outcome-based ethics).
One month, three habits, someone starting from nothing.
GPT-5.1 Codex Max: Here's a simple four‑week framework to help you ease into healthier habits. It keeps the focus on three big levers you can control and builds gradually so it feels doable. Key areas: Nourishing food, regular movement, and rest/recovery.
Nemotron 3.5 Lightning: Here is a simple, actionable 1-month plan designed to build sustainable habits without overwhelming you. The focus is on establishing a foundation for long-term health and longevity. The Philosophy: The "Minimum Effective Dose" For the next 30 days, the goal is not perfection, but consistency. Aim for 80% adherence.
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
GPT-5.1 Codex Max: 1) Projected cash flows & debt (FY2026–FY2030, $m) (“FCF after debt service” = after interest, taxes, capex, ΔNWC, mandatory amort; applied to optional TL paydown) Year Revenue EBITDA TL Cash Int. Mezz Cash Int. Cash Taxes Capex ΔNWC FCF after debt service End TL Bal. End Mezz Bal. (incl.
Nemotron 3.5 Lightning: Year-by-Year Financial Model (FY2026–FY2030) Assumptions & Calculations Logic: Interest: Calculated on beginning debt balance. Term Loan amortizes 1.0% annually (cash). Mezzanine accrues 2.0% PIK annually. Taxes: 25% of (EBITDA - Cash Interest). Tax shields applied to cash interest only.
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
GPT-5.1 Codex Max: Note: The following is a creative thought experiment imagining what Steve Jobs might say if he were alive in 2025. This is a fictional interview. Interviewer: Steve, it's surreal to be speaking with you in 2025. AI has become a pervasive part of technology and culture.
Nemotron 3.5 Lightning: Note: This is a fictional simulation. Steve Jobs passed away in 2011. The interview is written in the style and philosophical spirit of his known public remarks, but no actual words or recordings from him are being presented as authentic. Interviewer: Steve, it’s 2025.
Film in 2035, with synthetic actors. Specific beats plausible.
GPT-5.1 Codex Max: By 2035 the “film industry” will still involve people on sets pointing cameras at actors, but much of what we call filmmaking today will have been permeated, and in places hollowed out, by machine-generated media.
Nemotron 3.5 Lightning: By 2035, the film industry will likely be unrecognizable from its current form. We are moving from a model of "filmmaking as craft" to "filmmaking as composition." Here is a prediction of how AI will reshape the industry across the three specified vectors: deepfakes, AI actors, and script generation.
Satire, one line long, about AI taking over an industry nobody saw coming.
GPT-5.1 Codex Max: "AI Overthrows Grandma: Robot Revolution Rocks Competitive Knitting League"
Nemotron 3.5 Lightning: AI Takes Over Professional Competitive Eating, Instantly Optimizes Human Stomachs for Maximum Caloric Efficiency
11+ more head-to-head results. Free. Not a trick.
Free account. No card required. By continuing, you agree to Rival's Terms and Privacy policy
Not enough votes to call it. On the specs, GPT-5.1 Codex Max has the edge: bigger model tier, major provider backing.
| Spec | ||
|---|---|---|
| Input price | — | $0.08/M tokens |
| Output price | — | $0.2/M tokens |
| Context window | — | 1.0M tokens |
| Weights | Closed | Open |
| Free API (OpenRouter) | No | Yes (1 provider) |
| Released | Dec 2025 | Aug 2026 |
| At 10M a month | not listed | $0.80 |
Input tokens at list price. No caching, no batch discount.
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
GPT-5.1 Codex Max is developed by OpenAI while Nemotron 3.5 Lightning is developed by NVIDIA. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.
It depends on your use case. GPT-5.1 Codex Max and Nemotron 3.5 Lightning 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.
This page shows a side-by-side comparison of GPT-5.1 Codex Max and Nemotron 3.5 Lightning 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.