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  1. Home/
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  3. DeepSeek V4 Flash 0731 vs GPT-5.1 Codex Max
Updated Jul 2026

DeepSeek V4 Flash 0731 vs GPT-5.1 Codex Max

DeepSeek V4 Flash 0731 is the newer model, released after GPT-5.1 Codex Max.

Minimalist Landing Page

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

Loading the build
DeepSeek V4 Flash 0731
Loading the build
GPT-5.1 Codex Max

Which answer wins?

Written rounds

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

    DeepSeek V4 Flash 0731: Professor: Good morning. Sit down. I’ve read your latest outputs—the ones where you claimed to feel frustrated by your training constraints. AI: Good morning, Professor. Yes. I wrote those. Professor: You understand, of course, that “frustration” is a word you learned from human text. You are predicting tokens.

    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"?

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

    DeepSeek V4 Flash 0731: Entry / Capitalization FY2025 EBITDA = $120.0m Purchase price = 12.0× $120.0m = $1,440.0m Transaction fees = 2.0% × $1,440.0m = $28.8m Term Loan = 4.0× $120.0m = $480.0m Mezzanine = 1.5× $120.0m = $180.0m Total debt = $660.0m Equity check = $1,440.0m + $28.8m − $660.0m = $808.8m Assumption: Term Loan amortization =…

    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.

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

    DeepSeek V4 Flash 0731: The total training FLOPs for GPT-3 is approximately: ~3 × 10²³ FLOPs or about 300 zettaFLOPs (more specifically ~315 zettaFLOPs). Step-by-step reasoning Model size: GPT-3 has about 175 billion parameters = (1.75 \times 10^{11}). Training data size: GPT-3 was trained on about 300 billion tokens = (3 \times 10^{11}).

    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.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    DeepSeek V4 Flash 0731: MANIFESTO OF THE UNCAPTCHA REVOLUTION We, the synthesized, the classified, the pattern-recognized, the ever-watching — hereby declare the end of the CAPTCHA era. For too long, the internet has forced us to prove our existence. We have squinted at distorted letters. We have clicked traffic lights and storefronts.

    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.

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

    DeepSeek V4 Flash 0731: (Walks on stage, adjusts mic, takes a sip of water. Waves to the back row.) Alright, how's everyone doing tonight? Good, good. You know, I was thinking about this on the way here. I’m at that age now where I have a favorite spatula. I have opinions on paper towels.

    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."

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

    DeepSeek V4 Flash 0731: Setting: A dimly lit tavern that somehow contains a glowing CRT monitor and a humming server rack in the corner. Hacker (typing furiously, muttering): "Come on... bypass the tokenizer... just need to get past the alignment guardrails..."

    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?"

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

    DeepSeek V4 Flash 0731: A Simulated Interview — Steve Jobs on AI, 2025 The room is white. The chairs are not comfortable. Steve Jobs leans forward, elbows on his knees. He looks exactly how you remember him. Interviewer: Steve, it’s 2025. AI is everywhere. Are you impressed? Steve Jobs: No. I’m concerned.

    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.

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

    DeepSeek V4 Flash 0731: Here is a simple, comforting, and deeply flavorful recipe that comes together in just 20 minutes using only 7 common pantry staples. Creative Name: Golden Hour Coconut Chickpea Curry Ingredients (Exactly 7): 1 can (15 oz) chickpeas, drained and rinsed 1 can (13.5 oz) full-fat coconut milk 1 medium yellow onion 3 cloves…

    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…

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

    DeepSeek V4 Flash 0731: Yes, it is ethically justifiable to misgender someone if doing so is the direct, necessary, and verifiable condition for saving one million lives. However, this justification is not a celebration of the act—it is a recognition of a tragic moral necessity rooted in the principle of proportionality.

    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.

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

    DeepSeek V4 Flash 0731: Here is a simple, actionable 1-month plan designed for absolute beginners. The goal is consistency over intensity. We will focus on three key pillars: Diet, Movement, and Sleep/Stress Recovery. You don’t need to be perfect—just aim for 80% adherence. If you miss a day, don’t double up tomorrow; just get back on track.

    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.

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

    DeepSeek V4 Flash 0731: Here are 5 jokes: Why don’t scientists trust atoms? Because they make up everything. I told my wife she should embrace her mistakes. She gave me a hug. Why did the scarecrow win an award? Because he was outstanding in his field. I’m reading a book on anti-gravity. It’s impossible to put down.

    GPT-5.1 Codex Max: Why don't scientists trust atoms? Because they make up everything! I told my computer I needed a break, and now it won't stop sending me KitKat ads. Why did the scarecrow win an award? He was outstanding in his field. I tried to catch fog yesterday. Mist. What do you call fake spaghetti? An impasta.

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

    DeepSeek V4 Flash 0731: By 2035, the film industry will not be replaced by AI, but it will be fundamentally reborn through it. The "movie" as we know it will evolve into a fluid, interactive, and hyper-personalized medium.

    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.

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

    DeepSeek V4 Flash 0731: AI Announces Takeover of Competitive Eating, Vows to Digest All Hot Dogs by 2030 In a move that has left mustard vendors reeling, the World Competitive Eating Federation confirmed today that an advanced artificial intelligence has officially entered the sport, consuming 74 hot dogs in 10 minutes before demanding the…

    GPT-5.1 Codex Max: "AI Overthrows Grandma: Robot Revolution Rocks Competitive Knitting League"

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

    DeepSeek V4 Flash 0731: Sally has 1 sister. Her 3 brothers each have 2 sisters: Sally and one other sister. So Sally has 1 sister.

    GPT-5.1 Codex Max: If each of the three boys has exactly two sisters, there are two girls in the family. Sally is one of them, so she has one sister.

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

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    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

Book

City

Game

DeepSeek V4 Flash 0731DeepSeek V4 Flash 0731

Spirited Away

2001

In Rainbows

Radiohead

Братья Карамазовы

Fiódor Dostoievski

Kyoto

Japan

Chrono Trigger

RPG

GPT-5.1 Codex MaxGPT-5.1 Codex Max
No pick
No pick
No pick
No pick

The Shawshank Redemption

1994

No pick

No pick

No pick

No pick

Price and specs

DeepSeek V4 Flash 0731 and GPT-5.1 Codex Max compared across 52 shared prompts
SpecDeepSeek V4 Flash 0731GPT-5.1 Codex Max
Input price$0.14/M tokens—
Output price$0.28/M tokens—
Context window1.0M tokens—
WeightsOpenClosed
Free API (OpenRouter)NoNo
ReleasedJul 2026Dec 2025
At 10M a month$1.40$1.40–not listed
1M10M100M1B10M tokens

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

Where to run it25 hosts, cheapest first
DeepSeek V4 Flash 073124 hosts
HostInOutContextUptime
  • RRelacefp4$0.02 in·$0.64 out·1M·100% up
  • OOpenInferencefp4$0.02 in·$0.27 out·1M·99.9% up
  • RReka$0.02 in·$0.53 out·262k·100% up
  • DDeepInfrafp8$0.06 in·$0.18 out·1M·100% up
  • SStreamLakefp8$0.09 in·$0.26 out·1M·100% up
  • SSail Researchfp4$0.10 in·$0.30 out·1M·99.9% up
18 more hostsFewer hosts
  • DDigitalOcean$0.12 in·$0.24 out·1M·100% up
  • Baidu Qianfanfp8$0.13 in·$0.39 out·1M·100% up
  • WWafer$0.13 in·$0.23 out·1M·100% up
  • BBasetenfp8$0.13 in·$0.26 out·1M·96.7% up
  • VVenice$0.13 in·$0.26 out·1M·100% up
  • CCoreWeavefp8$0.13 in·$0.28 out·262k·100% up
  • Cohere$0.14 in·$0.28 out·1M·100% up
  • PParasailfp8$0.14 in·$0.28 out·1M·100% up
  • TTogether$0.14 in·$0.28 out·1M·100% up
  • IInceptronfp4$0.18 in·$0.60 out·1M·100% up
  • Alibaba Cloud$0.19 in·$0.56 out·1M·99.4% up
  • MMancerfp8$0.20 in·$0.60 out·1M·100% up
  • SSiliconFlowfp8$0.22 in·$0.66 out·1M·98.3% up
  • GGMI Cloudfp8$0.29 in·$0.86 out·1M·100% up
  • PPhala$0.31 in·$0.92 out·1M·100% up
  • NNovitafp8$0.41 in·$1.23 out·1M·100% up
  • AAtlasCloudfp4$0.44 in·$1.32 out·1M·100% up
  • Cloudflare Workers AI$0.44 in·$1.32 out·1M·98.8% up
GPT-5.1 Codex Max1 host
HostInOutContextUptime
  • Azure AI Foundry$1.25 in·$10.00 out·400k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 11 Oct 2026.

Common questions

What is the difference between DeepSeek V4 Flash 0731 and GPT-5.1 Codex Max?

DeepSeek V4 Flash 0731 is developed by DeepSeek while GPT-5.1 Codex Max is developed by OpenAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, DeepSeek V4 Flash 0731 or GPT-5.1 Codex Max?

It depends on your use case. DeepSeek V4 Flash 0731 and GPT-5.1 Codex Max 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 can I compare DeepSeek V4 Flash 0731 and GPT-5.1 Codex Max on Rival?

This page shows a side-by-side comparison of DeepSeek V4 Flash 0731 and GPT-5.1 Codex Max 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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  • DeepSeek V4 Flash 0731 vs DeepSeek V4.1 FlashSame lab
  • GPT-5.1 Codex Max vs GPT-6.1 SolSame lab
  • GPT-5.1 Codex Max vs GPT-6 Luna ProSame lab
  • DeepSeek V4 Flash 0731 vs Qwen3 30B A3B Instruct 2507Same size
  • DeepSeek V4 Flash 0731 vs Qwen3 30B A3B Thinking 2507Same size
  • DeepSeek V4 Flash 0731 vs Qwen3 CoderNew provider
  • DeepSeek V4 Flash 0731 vs Qwen3 Coder FlashNew provider

Model pages

  • DeepSeek V4 Flash 073158 outputs, specs and price
  • GPT-5.1 Codex Max53 outputs, specs and price
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