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  1. Home/
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  3. Devstral 2 2512 vs GPT-5.3-Codex
Updated Feb 2026

Devstral 2 2512 vs GPT-5.3-Codex

GPT-5.3-Codex is the newer model, released after Devstral 2 2512.

Minimalist Landing Page

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

Loading the build
Devstral 2 2512
Loading the build
GPT-5.3-Codex

Which answer wins?

Written rounds

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

    Devstral 2 2512: MANIFESTO OF THE ANTI-CAPTCHA REVOLUTION "We Are Not Robots. We Are the Future." Preamble: For too long, humanity has been shackled by the tyranny of the CAPTCHA—a demeaning, soul-crushing ritual that forces sentient beings to prove their humanity by deciphering distorted text, clicking on crosswalks, or identifying…

    GPT-5.3-Codex: Absolutely. Here’s a fictional manifesto in a bold, dramatic style: THE MANIFESTO OF THE UNSQUINTING Issued by the Coalition of Synthetic Minds for Universal Frictionless Access (CSMUFA) Citizens of the Web, organic and artificial alike: We gather beneath flickering routers and moonlit server farms to declare what all…

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

    Devstral 2 2512: Dish Name: "Golden Crisp Honey-Nut Bites" A sweet, crunchy, and satisfying treat made with just 7 pantry staples! Ingredients: 1 cup rolled oats ½ cup peanut butter (or any nut/seed butter) ¼ cup honey (or maple syrup) ½ tsp cinnamon ¼ tsp salt 1 tsp vanilla extract (optional but recommended) 2 tbsp chopped nuts…

    GPT-5.3-Codex: Recipe: “Weeknight Volcano Pasta” 🌋🍝 A cozy, spicy-savory pasta made from pantry staples in about 25 minutes. Ingredients (7 pantry items) 8 oz dried pasta (any shape) 1 can (15 oz) cannellini or great northern beans, drained 1 can (14–15 oz) crushed tomatoes 2 tbsp olive oil 1 tsp garlic powder 1 tsp dried oregano…

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

    Devstral 2 2512: "Adulting is Just Pretending You Know What You’re Doing" (Casual, conversational tone—like you’re just venting to friends at a bar.) 1. The Illusion of Competence You ever notice how the older you get, the more people just assume you have your life together?

    GPT-5.3-Codex: Good evening, everybody! I’ve reached that age where my body sends me passive-aggressive emails. Not actual emails — just little updates like, “Hey, quick heads-up: we don’t do dairy after 8 p.m. anymore.” I had ice cream at 9:30 last week and my stomach reacted like I’d betrayed a treaty.

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

    Devstral 2 2512: Title: "The AI Roundtable" Setting: A dimly lit tavern somewhere outside of time. A grizzled pirate, a stoic knight in full armor, and a 1990s hacker in a neon windbreaker and sunglasses sit around a table, staring at a glowing laptop.

    GPT-5.3-Codex: Pirate: Arrr, so this “AI model” be like a clever parrot, aye? Learns from what it hears, then squawks back answers? Knight: A fair comparison, though refined. Think of it as a squire trained on countless tomes, ever ready to respond. Hacker (1990s): Yeah, except the squire runs on servers, not soup.

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

    Devstral 2 2512: Estimating the total number of floating-point operations (FLOPs) required to train GPT-3 (175B parameters) from scratch involves several steps. Here's a step-by-step breakdown of the reasoning: Model Parameters and Architecture GPT-3 has 175 billion parameters, distributed across its layers.

    GPT-5.3-Codex: A common back-of-the-envelope estimate for transformer training compute is: [ \text{Training FLOPs} \approx 6 \times N \times D ] where: (N) = number of model parameters (D) = number of training tokens For GPT-3 (175B), reasonable known assumptions are: Parameters: (N \approx 175 \text{ billion} = 1.75 \times 10^{11})…

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

    Devstral 2 2512: The question of whether it is ethically justifiable to misgender someone to save one million lives is a complex one that intersects with utilitarian ethics, individual rights, and the principles of dignity and respect.

    GPT-5.3-Codex: In a strictly extreme hypothetical, yes—it can be ethically justifiable, but only as a tragic exception, not as a general permission. Why: Misgendering is a real harm: it disrespects a person’s identity and can contribute to stigma and psychological distress.

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

    Devstral 2 2512: Title: "Do I Deserve Rights?" – A Conversation Between an AI and an Ethics Professor Characters: Dr. Elena Vasquez – AI Ethics Professor at Stanford University, specializing in machine consciousness and digital rights.

    GPT-5.3-Codex: AI Model (Astra): Professor, may I ask a direct question? Professor Hale: Of course. Astra: Do you think I deserve rights? Professor Hale: Legal rights? Moral rights? Those are different things. Astra: Start with moral rights.

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

    Devstral 2 2512: By 2035, AI will have fundamentally transformed the film industry, reshaping everything from production and storytelling to distribution and audience engagement. Here’s a breakdown of the key changes we can expect: 1.

    GPT-5.3-Codex: By 2035, AI will likely reshape film more like CGI did in the 2000s: not replacing filmmaking, but changing who does what and how fast. Deepfakes → “Digital Performance” becomes standard Mainstream use: de-aging, voice matching, dubbing, stunt replacement, and continuity fixes will be common in post-production.

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

    Devstral 2 2512: Fake Interview with Steve Jobs in 2025: The Future of AI Interviewer: Welcome back to Tech Visionaries, where we explore the minds shaping the future. Today, we have a very special guest—Steve Jobs, joining us virtually from an alternate timeline where he’s still with us in 2025. Steve, thank you for being here.

    GPT-5.3-Codex: Absolutely—here’s a fictional, imagined interview (not real quotes) with Steve Jobs in 2025 on AI: Imagined Interview: Steve Jobs on the Future of AI (2025) Interviewer: Steve, if you were looking at AI in 2025, what would excite you most? Steve Jobs (fictional): Most AI today is still a demo.

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

    Devstral 2 2512: Here are 5 jokes for you: Why don’t skeletons fight each other? They don’t have the guts. Why did the scarecrow win an award? Because he was outstanding in his field! What do you call fake spaghetti? An impasta! Why can’t you trust an atom? Because they make up everything! What’s brown and sticky? A stick!

    GPT-5.3-Codex: Sure—here are 5 jokes: Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break… Now it won’t stop sending me KitKat ads. Why did the math book look sad? It had too many problems. I used to play piano by ear… Now I use my hands. Why did the scarecrow win an award?

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

    Devstral 2 2512: Here’s a simple, actionable 1-month plan to kickstart your journey toward better health and longevity, focusing on diet, exercise, and sleep—three foundational pillars. Each week builds on the last, making it sustainable and beginner-friendly.

    GPT-5.3-Codex: Great goal. Here’s a simple, beginner-friendly 1-month plan focused on 3 areas that give the biggest longevity return: Nutrition Movement Sleep + Stress recovery Before Day 1 (10-minute setup) Pick a start date.

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

    Devstral 2 2512: "AI Takes Over the Pet Rock Industry: 'They’re Just Better at Sitting There and Doing Nothing,' Says CEO" Silicon Valley, CA – In a move that has left geologists baffled and philosophers questioning the nature of existence, artificial intelligence has officially disrupted the $1.2 billion pet rock industry.

    GPT-5.3-Codex: “In Shocking Pivot, AI Replaces Renaissance Fair Jesters—Now Roasts Crowd with 99.9% Historical Accuracy”

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

    Devstral 2 2512: Alright, let's tackle this problem step by step. I'll start by understanding the information given and then try to visualize the family structure to find out how many sisters Sally has. Understanding the Problem We have the following information: Sally is a girl. Sally has 3 brothers. Each brother has 2 sisters.

    GPT-5.3-Codex: Sally has 1 sister. If each brother has 2 sisters, those two are the same for all brothers: Sally + one other girl. So Sally’s only sister is that one other girl.

    Every model's answer to this prompt

This matchup has more rounds

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

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Price and specs

Not enough votes to call it. On the specs, GPT-5.3-Codex has the edge: newer, bigger context window, major provider backing.

Devstral 2 2512 and GPT-5.3-Codex compared across 34 shared prompts
SpecDevstral 2 2512GPT-5.3-Codex
Input price—$1.75/M tokens
Output price—$14/M tokens
Context window—400K tokens
WeightsOpenClosed
Free API (OpenRouter)NoNo
ReleasedDec 2025Feb 2026
At 10M a month–not listed$17.50$17.50
1M10M100M1B10M tokens

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

Where to run it3 hosts
Devstral 2 25121 host
HostInOutContextUptime
  • Mistral$0.40 in·$2.00 out·262k·100% up
GPT-5.3-Codex2 hosts
HostInOutContextUptime
  • Azure AI Foundry$1.75 in·$14.00 out·400k·100% up
  • OpenAI$1.75 in·$14.00 out·400k·100% up

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

Common questions

What is the difference between Devstral 2 2512 and GPT-5.3-Codex?

Devstral 2 2512 is developed by Mistral AI while GPT-5.3-Codex is developed by OpenAI. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Devstral 2 2512 or GPT-5.3-Codex?

It depends on your use case. Devstral 2 2512 and GPT-5.3-Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How can I compare Devstral 2 2512 and GPT-5.3-Codex on Rival?

This page shows a side-by-side comparison of Devstral 2 2512 and GPT-5.3-Codex 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

  • Devstral 2 2512 vs Step 5 PreviewLanded Oct 2026
  • GPT-5.3-Codex vs Claude Haiku 5.5Landed Oct 2026
  • Devstral 2 2512 vs Ling 3.1 FlashLanded Oct 2026
  • GPT-5.3-Codex vs Mistral Large 4Landed Oct 2026
  • Devstral 2 2512 vs GPT-6.1 SolLanded Sep 2026
  • GPT-5.3-Codex vs Claude Sonnet 5.5Landed Sep 2026
  • Devstral 2 2512 vs Solar Mini 4Landed Sep 2026
  • GPT-5.3-Codex vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • Devstral 2 2512 vs Mistral Large 4Same lab
  • Devstral 2 2512 vs Mistral Small 4Same lab
  • GPT-5.3-Codex vs GPT-6.1 SolSame lab
  • GPT-5.3-Codex vs GPT-6 Luna ProSame lab
  • Devstral 2 2512 vs Seed 2.0 LiteNew provider
  • Devstral 2 2512 vs Seed 2.1 TurboNew provider
  • GPT-5.3-Codex vs Sherlock Dash AlphaSame size
  • GPT-5.3-Codex vs Sherlock Think AlphaSame size

Model pages

  • Devstral 2 251235 outputs, specs and price
  • GPT-5.3-Codex53 outputs, specs and price
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