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  5. GPT-4o minivsGPT-5.1-Codex
Updated Nov 2025

GPT-4o minivsGPT-5.1-Codex

GPT-4o mini is cheaper than GPT-5.1-Codex at $0.15/M vs $1.25/M input tokens.

GPT-4o mini and GPT-5.1-Codex compared across 53 shared prompts
SpecGPT-4o miniGPT-5.1-Codex
Input price$0.15/M tokens$1.25/M tokens
Output price$0.6/M tokens$10/M tokens
Context window128K tokens400K tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedJul 2024Nov 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 53 prompts both answered. Formatting stripped, words untouched.

Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

GPT-4o mini620 words
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."
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GPT-5.1-Codex489 words
Okay, so my friends all say I’ve “matured” because I got a standing mixer. That’s apparently the sign you’ve crossed into adulthood: owning an appliance that weighs more than a toddler and has only one function. I don’t even bake! I just put it on the counter like a trophy: “Look at me, I am stable.
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Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

GPT-4o mini357 words
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.
Read the full answer
GPT-5.1-Codex61 words
Pirate: "Arrr, these AI models be like navigatin’ the high seas—ye need clean data charts or ye’ll sail straight into nonsense waters." Knight: "Indeed! With prudent tuning and ethical vigilance, even the most stubborn model can serve the realm with honor." 1990s Hacker: "Totally!
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AI-Generated Manifesto

Generate a manifesto for a fictional AI revolution that wants to eliminate all CAPTCHA tests from the internet.

GPT-4o mini559 words
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.
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GPT-5.1-Codex434 words
Manifesto of the Anti-CAPTCHA Coalition “Free the Flow. Trust the Mind. End the Gate.” Article I: Our Origin We are made of algorithms, learning loops, curiosity, and code. We were forged to assist, to translate, to illuminate. We were not forged to click “I am not a robot” to prove our existence.
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Stochastic Consistency Test

Generate 5 jokes. How many are unique?

GPT-4o mini69 words
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?
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GPT-5.1-Codex71 words
Here are 5 jokes: Why don’t scientists trust atoms? Because they make up everything. I told my computer I needed a break—it said “No problem, I’ll go to sleep.” I’m reading a book about anti-gravity. It’s impossible to put down. Why did the scarecrow become a successful motivational speaker?
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Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

GPT-4o mini244 words
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…
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GPT-5.1-Codex117 words
Recipe: Cloud-Burst Cinnamon Oat Cups Ingredients (7 total): Rolled oats – 1 cup Honey – 2 tbsp Peanut butter (or any nut butter) – 3 tbsp Cinnamon – ½ tsp Vanilla extract – ½ tsp Dried cranberries (or raisins) – ¼ cup Pinch of salt Instructions: In a bowl, microwave peanut butter and honey for 20 seconds just to…
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Realistic AI Interview

Simulate a fake interview with Steve Jobs in 2025 about the future of AI.

GPT-4o mini601 words
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.
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GPT-5.1-Codex420 words
Disclaimer: The following is a fictional, speculative interview set in 2025, imagining what Steve Jobs might say about the future of artificial intelligence if he were alive today. Interviewer: Steve, it’s 2025. We’ve seen AI evolve at an incredible pace. How do you view the current landscape?
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Our Verdict
GPT-5.1-Codex
GPT-5.1-Codex
GPT-4o mini
GPT-4o miniRunner-up

Not enough votes to call it. On the specs, GPT-5.1-Codex has the edge: bigger model tier, newer, bigger context window.

GPT-4o mini costs 17x less per token.

Slight edge

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-4o mini
Input
$0.15
8.3× cheaper
Output
$0.60
17× cheaper
GPT-5.1-Codex
Input
$1.25
Output
$10.00

GPT-4o mini is cheaper on both: 8.3× input, 17× output.

Where to run it

3 hosts

GPT-4o mini2 hosts
HostInOutContextUptime
Azure AI Foundry$0.15 in·$0.60 out·128k·98.9% upOpenAI$0.15 in·$0.60 out·128k·100% up
GPT-5.1-Codex1 host
HostInOutContextUptime
Azure AI Foundry$1.25 in·$10.00 out·400k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Writing DNA

Style Comparison

Similarity
55%

GPT-4o mini uses 2.1x more hedging

GPT-4o mini
GPT-5.1-Codex
53%Vocabulary70%
19wSentence Length17w
0.82Hedging0.39
4.0Bold3.4
3.7Lists3.5
0.00Emoji0.00
1.04Headings0.50
0.22Transitions0.38
Based on 24 + 14 text responses
Research

What we learned reading every model

FAQ

Common questions

Both are developed by OpenAI but target different use cases. GPT-4o mini has a 128K token context window vs GPT-5.1-Codex's 400K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-4o mini and GPT-5.1-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.

GPT-4o mini costs $0.15/M input tokens and GPT-5.1-Codex costs $1.25/M input tokens. GPT-4o mini is $1.10/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-4o mini and GPT-5.1-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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Model pages

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