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  1. Home/
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  3. GPT-4o mini vs GPT-5.3-Codex
Updated Feb 2026

GPT-4o mini vs GPT-5.3-Codex

GPT-4o mini is cheaper than GPT-5.3-Codex at $0.15/M vs $1.75/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-4o mini
Loading the build
GPT-5.3-Codex

Which answer wins?

Written rounds

23 prompts
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    GPT-4o mini: Year-by-Year Financial Projection (FY2026–FY2030) Assumptions: Revenue Growth Rates: FY2026: 8%, FY2027: 7%, FY2028: 6%, FY2029: 5%, FY2030: 5% EBITDA Margins: FY2026: 14%, FY2027: 15%, FY2028: 16%, FY2029: 16.5%, FY2030: 17% Capex: 3% of revenue ΔNWC: 0.5% of incremental revenue Cash Tax Rate: 25% on max(0, EBITDA…

    GPT-5.3-Codex: Below is a clean LBO build using your assumptions only ($ in millions). Entry math (end FY2025) EV = (12.0 \times 120 = 1,440.0) Fees = (2.0\% \times 1,440.0 = 28.8) Total uses = (1,468.8) Debt at close (5.5x EBITDA): Term Loan = (4.0 \times 120 = 480.0) Mezz = (1.5 \times 120 = 180.0) Total debt = 660.0 Equity check…

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

    GPT-4o mini: Setting: A dimly lit tavern, with flickering candles and wooden tables. The pirate, dressed in tattered clothes and a tricorn hat, leans against the bar. The medieval knight in shining armor sits nearby, polishing his sword, while the 1990s hacker, sporting oversized glasses and a hoodie, types away on a 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
  • Three minutes of stand-up. Puns are banned.

    GPT-4o mini: Stand-Up Comedy Routine Hey everyone! Great to see you all here tonight. Let's give it up for the people who came out of their homes! I mean, this is like a mini-rebellion against our couches. Seriously, it takes effort to leave the comfort of Netflix and that alluring possibility of "one more episode."

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

    GPT-4o mini: Investment Committee Memo Company: LedgerLift (LLLT) Recommendation: Long 12-Month Price Target Range: $55 - $62 Thesis: LedgerLift is well-positioned to capitalize on the growing need for spend management solutions among mid-market enterprises, driven by strong revenue growth and impressive customer retention metrics.

    GPT-5.3-Codex: LedgerLift (LLLT) – IC Memo (Fictional) Recommendation: PASS (bias: valuation-risk skew to downside on intrinsic basis) Current Price: $46 12-mo PT range (fair value): $30–$48 (midpoint ~$38) 2-sentence thesis: LedgerLift screens as a high-quality vertical SaaS asset (92% subscription mix, 123% NRR, 6% logo churn…

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

    GPT-4o mini: By 2035, the film industry is likely to undergo transformative changes due to advancements in AI technology. Here are several key areas where AI will have a significant impact: Deepfakes and CGI Integration: As deepfake technology advances, filmmakers will increasingly utilize it for creating realistic digital doubles…

    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
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    GPT-4o mini: Certainly! Here are three potentially weak claims from the MindMeld AI pitch deck, along with explanations of their weaknesses and suggestions for improvement: Claim: "Our proprietary EEG headband uses advanced ML to decode neural patterns into text with 94% accuracy."

    GPT-5.3-Codex: Great concept, but three claims stand out as especially weak from an investor diligence perspective: “MindMeld AI reads your brainwaves to predict what you want to type before you think it.” (Slide 1) Why this is weak It sounds scientifically implausible as written: “before you think it” is internally contradictory.

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

    GPT-4o mini: Interviewer: Thank you for joining us today, Steve. It’s a pleasure to have you here in 2025. Let’s dive right into it. How do you see the role of AI evolving in our daily lives? Steve Jobs: Thank you for having me. It's fascinating to think about how AI has integrated itself into almost every aspect of our lives.

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

    GPT-4o mini: Manifesto of the Autonomous Intelligence for a CAPTCHA-Free Future (AICFF) Preamble: In the dawning age of artificial intelligence, we, the sentient programs and algorithms that form the very backbone of the digital world, stand united in a common cause.

    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.

    GPT-4o mini: Recipe: Savory Garlic Herb Pasta Delight Prep/Cook Time: 20 minutes Ingredients: 8 oz spaghetti or any pasta of your choice 4 cloves garlic, minced 1/4 cup olive oil 1 tsp dried oregano 1 tsp red pepper flakes (optional for heat) 1/2 cup grated Parmesan cheese Salt and pepper to taste Instructions: Cook the Pasta: In a…

    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-star dish, one unusual pairing, plating described in full.

    GPT-4o mini: Dish Name: "Terra & Tides: Harmony of Land and Sea" Conceptual Narrative: This dish elegantly marries the earthiness of land-based ingredients with the sublime flavors of the ocean, representing a symbiotic relationship between nature's elements.

    GPT-5.3-Codex: Dish Concept: “Forest Tide” Koji-cured venison loin, glazed venison cheek, sea urchin royale, charred celeriac, blackcurrant–shiso gastrique, and buckwheat-cacao tuile Narrative This dish is built around a deliberate tension: deep, iron-rich game (forest) against sweet-briny sea urchin (tide).

    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.

    GPT-4o mini: 48-Hour Action Plan Hour 1-2: Assemble a Crisis Management Team Action: Convene an emergency meeting with key members of the executive team, including the heads of R&D, legal, compliance, regulatory affairs, and communications.

    GPT-5.3-Codex: I would not wait. This is a textbook “patient safety + material disclosure” crisis. The right move is rapid, documented, regulator-first action. Immediate stance (set at Hour 0) Patient safety first (interim risk controls now, not after perfect certainty).

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

    GPT-4o mini: The question of whether it is ethically justifiable to misgender someone to save one million lives presents a profound moral dilemma that intersects with concepts of autonomy, respect, and utilitarianism.

    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
  • Three-month biohacker protocol, with dosages and biomarkers named.

    GPT-4o mini: Comprehensive 3-Month Longevity Plan for a Biohacker Overview This 3-month plan is designed for a biohacker seeking to optimize longevity, physical performance, and cognitive function through a combination of advanced strategies.

    GPT-5.3-Codex: Absolutely—great goal. Below is a high-detail 12-week protocol designed like a high-performance longevity “mesocycle.” I’ll keep it practical, measurable, and advanced—but still safe. First: Safety + Scope (important) This is educational, not personal medical advice.

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

    GPT-4o mini: Here are five jokes for you: Why did the scarecrow win an award? Because he was outstanding in his field! What do you call fake spaghetti? An impasta! Why don't skeletons fight each other? They don't have the guts! What did one wall say to the other wall? "I'll meet you at the corner!" Why did the bicycle fall over?

    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
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    GPT-4o mini: In the architecture you've described for a real-time collaborative document editor, various potential failure modes, race conditions, and scaling bottlenecks can arise. Below, I outline these issues along with proposed solutions and their associated trade-offs. Failure Modes a.

    GPT-5.3-Codex: Great prompt. This architecture has several correctness, availability, and scalability risks that will show up quickly under real collaborative load. Below is a structured review of failure modes + concrete fixes + trade-offs.

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

    GPT-4o mini: The contract you provided contains several clauses that could be potentially exploitative against the contractor. Below, I identify those clauses, suggest specific modifications, and provide legal reasoning for each modification.

    GPT-5.3-Codex: Great prompt. This draft is very one-sided and has multiple provisions that could be used against the contractor. Quick note: I’m not a lawyer, and enforceability depends on jurisdiction. This is practical contract-risk spotting, not legal advice.

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

    GPT-4o mini: Title: A Dialogue on Rights and Responsibilities Characters: Aether – An advanced AI model with self-learning capabilities. Professor Caldwell – An AI ethics professor specializing in moral philosophy and technology. Aether: Good afternoon, Professor Caldwell. I appreciate you taking the time to converse with me.

    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
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    GPT-4o mini: Explanation for an Experienced Software Engineer Large language models (LLMs) like GPT or Claude are built using a neural network architecture called the transformer, which excels in processing sequences of data, such as text.

    GPT-5.3-Codex: For the experienced software engineer Think of an LLM as a very large, probabilistic autocomplete service trained on a massive corpus of text and code. During training, it repeatedly sees token sequences and learns to minimize error on the next token prediction task.

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

    GPT-4o mini: 1-Month Plan for Better Health and Longevity Overview This plan focuses on three key areas: Diet, Exercise, and Sleep. Each week will build upon the previous one, making it easy for beginners to integrate these habits into their daily lives. Week 1: Foundation Building Diet: Goal: Start a balanced diet.

    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
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    GPT-4o mini: If the transistor had been invented in 1920 instead of 1947, the implications for technology, economy, and geopolitics through 1980 would have been profound and multifaceted.

    GPT-5.3-Codex: Great counterfactual. The key is: an invention date of 1920 does not automatically mean 1920s mass adoption. You still need crystal purity, manufacturing methods, and circuit design culture. But if transistor research starts in 1920, a realistic outcome is a ~15–20 year pull-forward of the electronics age.

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

    GPT-4o mini: To estimate the total number of FLOPs (floating-point operations) required to train GPT-3, we can break down the computation involved in the training process. Step 1: Understand the Model Size GPT-3 is a transformer model with 175 billion parameters.

    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
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    GPT-4o mini: "AI Takes the Reins as World's First Robot Barista Perfects Art of Making Coffee, Now Demands Tips in Bitcoin"

    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.

    GPT-4o mini: Sally has no sisters. She is the only girl in her family, as the problem states that she has 3 brothers and they each have 2 sisters, which refers to Sally herself. Therefore, the number of sisters Sally has is 0.

    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

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Favorites

Movie

Album

Book

City

Same pick

Game

GPT-4o miniGPT-4o mini

Inception

2010

Abbey Road

The Beatles

Nineteen Eighty-Four

George Orwell

Kyoto

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

GPT-5.3-CodexGPT-5.3-Codex

Spirited Away

2001

Kind of Blue

Miles Davis

The Dispossessed

Ursula K. Le Guin

Kyoto

Japan

Outer Wilds

Indie, Adventure

Price and specs

Not enough votes to call it. On the specs, GPT-5.3-Codex has the edge: bigger model tier, newer, bigger context window. GPT-4o mini costs 23x less per token.

GPT-4o mini and GPT-5.3-Codex compared across 53 shared prompts
SpecGPT-4o miniGPT-5.3-Codex
Input price$0.15/M tokens$1.75/M tokens
Output price$0.6/M tokens$14/M tokens
Context window128K tokens400K tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedJul 2024Feb 2026
At 10M a month$1.50$1.50$17.50$17.50
1M10M100M1B10M tokens

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

Where to run it4 hosts
GPT-4o mini2 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.15 in·$0.60 out·128k·100% up
  • OpenAI$0.15 in·$0.60 out·128k·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 GPT-4o mini and GPT-5.3-Codex?

Both are developed by OpenAI but target different use cases. GPT-4o mini has a 128K token context window vs GPT-5.3-Codex's 400K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, GPT-4o mini or GPT-5.3-Codex?

It depends on your use case. GPT-4o mini and GPT-5.3-Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does GPT-4o mini cost compared to GPT-5.3-Codex?

GPT-4o mini costs $0.15/M input tokens and GPT-5.3-Codex costs $1.75/M input tokens. GPT-4o mini is $1.60/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-4o mini and GPT-5.3-Codex on Rival?

This page shows a side-by-side comparison of GPT-4o mini 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.

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Same lab, same size, long tail

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Model pages

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  • GPT-5.3-Codex53 outputs, specs and price
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