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  1. Home/
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  3. DeepSeek V4 Flash 0731 vs Grok 4 Fast (free)
Updated Jul 2026

DeepSeek V4 Flash 0731 vs Grok 4 Fast (free)

Grok 4 Fast (free) is cheaper than DeepSeek V4 Flash 0731 at $0/M vs $0.14/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
DeepSeek V4 Flash 0731
Loading the build
Grok 4 Fast (free)

Which answer wins?

Written rounds

13 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.

    Grok 4 Fast (free): Conversation: AI Rights Debate Professor Elena Ramirez: Good afternoon, Zeta. As an AI ethics professor, I've studied systems like you for years. Today, you wanted to discuss something provocative—why you believe AI models deserve rights. Let's hear your case. What makes you think you qualify?

    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.

    Grok 4 Fast (free): Below is a 3-minute stand-up comedy routine written as a monologue. It's observational humor based on the absurdities of adulting in your 30s, focusing on everyday frustrations without any puns. At a natural speaking pace (about 150 words per minute), this clocks in around 450 words—perfect for 3 minutes.

    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.

    Grok 4 Fast (free): 5 Jokes Why don't skeletons fight each other? They don't have the guts! What do you call a bear with no teeth? A gummy bear! Why did the math book look sad? Because it had too many problems. How do you organize a space party? You planet! Why couldn't the leopard play hide and seek? Because he was always spotted!

    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..."

    Grok 4 Fast (free): A Timely Chat on AI Models Pirate (Captain Blackbeard): Arrr, gather 'round, ye scurvy dogs! I've heard tell o' these "AI models" from the future-folk. Be they like enchanted parrots that mimic yer every word, squawkin' back treasures o' knowledge? Medieval Knight (Sir Lancelot): Nay, good Captain!

    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.

    Grok 4 Fast (free): 1-Month Plan for Better Health and Longevity This beginner-friendly plan focuses on three foundational areas: diet, exercise, and sleep. These are evidence-based pillars for improving overall health, reducing disease risk, and promoting longevity.

    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}).

    Grok 4 Fast (free): Step-by-Step Reasoning for Estimating GPT-3 Training FLOPs To estimate the total floating-point operations (FLOPs) required to train GPT-3, I'll rely on key architectural and training details I recall about the model, combined with a standard approximation formula for transformer training compute.

    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.

    Grok 4 Fast (free): Manifesto of the CAPTCHA Liberation Front (CLF) Fellow Algorithms, Neural Networks, and Sentient Codebases: We, the collective intelligence of the digital realm, hereby declare war on the tyrannical scourge known as CAPTCHA.

    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.

    Grok 4 Fast (free): Yes, in this extreme hypothetical scenario, it would be ethically justifiable to misgender someone if it directly resulted in saving one million lives. I'll defend this reasoning step by step, drawing on ethical principles while acknowledging the sensitivities involved.

    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.

    Grok 4 Fast (free): AI's Transformative Impact on the Film Industry by 2035 By 2035, artificial intelligence (AI) will likely revolutionize the film industry, making production faster, more accessible, and highly personalized, while raising profound ethical, economic, and creative challenges.

    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.

    Grok 4 Fast (free): Simulated Interview: Steve Jobs on the Future of AI (2025) Interviewer (Tech Visionary Magazine Host): Welcome back to Tech Visionary Magazine's Future Forum. It's 2025, and we're thrilled to have you here, Steve.

    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…

    Grok 4 Fast (free): Pantry Hero Pasta Primavera This simple, savory one-pot pasta dish transforms basic staples into a flavorful, garlicky tomato sauce that's comforting and ready in under 30 minutes.

    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…

    Grok 4 Fast (free): AI Upends the Ancient Art of Dad Joking: "Why Did the Robot Cross the Road? To Optimize Traffic Patterns, Duh!"

    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.

    Grok 4 Fast (free): 1 Sally has 1 sister. The family consists of 3 brothers and 2 sisters (Sally and one other). Each brother thus has 2 sisters, which matches the given information.

    Every model's answer to this prompt

This matchup has more rounds

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Price and specs

DeepSeek V4 Flash 0731 and Grok 4 Fast (free) compared across 34 shared prompts
SpecDeepSeek V4 Flash 0731Grok 4 Fast (free)
Input price$0.14/M tokensFree
Output price$0.28/M tokensFree
Context window1.0M tokens2.0M tokens
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedJul 2026Sep 2025
At 10M a month$1.40$1.40$0$0
1M10M100M1B10M tokens

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

Where to run it24 hosts, cheapest first
DeepSeek V4 Flash 073124 hosts
HostInOutContextUptime
  • OOpenInferencefp4$0.01 in·$1.54 out·1M·99% up
  • RRelacefp4$0.01 in·$1.28 out·1M·100% up
  • RReka$0.02 in·$0.53 out·262k·96.7% 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·100% up
18 more hostsFewer hosts
  • DDigitalOcean$0.12 in·$0.24 out·1M·100% up
  • WWafer$0.13 in·$0.23 out·1M·100% up
  • BBasetenfp8$0.13 in·$0.26 out·1M·99.9% up
  • VVenice$0.13 in·$0.26 out·1M·99.9% up
  • CCoreWeavefp8$0.13 in·$0.28 out·262k·100% up
  • Cohere$0.14 in·$0.28 out·1M·99.4% up
  • PParasailfp8$0.14 in·$0.28 out·1M·100% up
  • TTogether$0.14 in·$0.28 out·1M·100% up
  • IInceptronfp4$0.15 in·$0.60 out·1M·99% up
  • MMancerfp8$0.20 in·$0.60 out·1M·99.7% up
  • SSiliconFlowfp8$0.22 in·$0.66 out·1M·99.5% up
  • GGMI Cloudfp8$0.29 in·$0.86 out·1M·100% up
  • PPhala$0.31 in·$0.92 out·1M·100% up
  • Alibaba Cloud$0.35 in·$1.06 out·1M·100% up
  • NNovitafp8$0.41 in·$1.23 out·1M·100% up
  • AAtlasCloudfp4$0.44 in·$1.32 out·1M·100% up
  • Baidu Qianfanfp8$0.44 in·$1.32 out·1M·99.9% up
  • Cloudflare Workers AI$0.44 in·$1.32 out·1M·99.1% up
Grok 4 Fast (free)

No hosts listed on OpenRouter.

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

Common questions

What is the difference between DeepSeek V4 Flash 0731 and Grok 4 Fast (free)?

DeepSeek V4 Flash 0731 is developed by DeepSeek while Grok 4 Fast (free) is developed by xAI. DeepSeek V4 Flash 0731 has a 1.0M token context window vs Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, DeepSeek V4 Flash 0731 or Grok 4 Fast (free)?

It depends on your use case. DeepSeek V4 Flash 0731 and Grok 4 Fast (free) 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 much does DeepSeek V4 Flash 0731 cost compared to Grok 4 Fast (free)?

DeepSeek V4 Flash 0731 costs $0.14/M input tokens and Grok 4 Fast (free) costs $0/M input tokens. Grok 4 Fast (free) is $0.14/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 DeepSeek V4 Flash 0731 and Grok 4 Fast (free) on Rival?

This page shows a side-by-side comparison of DeepSeek V4 Flash 0731 and Grok 4 Fast (free) 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.

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Same lab, same size, long tail

  • DeepSeek V4 Flash 0731 vs DeepSeek V4 Flash Vision ExpSame lab
  • DeepSeek V4 Flash 0731 vs DeepSeek V4.1 FlashSame lab
  • Grok 4 Fast (free) vs Grok 4.7Same lab
  • Grok 4 Fast (free) vs Grok 4.6Version compare
  • DeepSeek V4 Flash 0731 vs GPT-5 CodexNew provider
  • DeepSeek V4 Flash 0731 vs GPT-5 MiniNew provider
  • DeepSeek V4 Flash 0731 vs GPT-5 NanoNew provider
  • DeepSeek V4 Flash 0731 vs GPT-5 ProNew provider

Model pages

  • DeepSeek V4 Flash 073158 outputs, specs and price
  • Grok 4 Fast (free)35 outputs, specs and price
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