Updated Nov 24, 2025

Our Verdict

Claude Opus 4.5

GPT-4o (Omni)

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

Writing DNA

Style Comparison

Similarity

100%

Claude Opus 4.5 uses 6.0x more emoji

Claude Opus 4.5

GPT-4o (Omni)

64%Vocabulary54%

55wSentence Length18w

0.86Hedging0.72

5.8Bold7.3

4.5Lists5.6

0.15Emoji0.03

1.59Headings1.40

0.05Transitions0.26

Based on 24 + 24 text responses

vs

Ask them anything yourself

Claude Opus 4.5

GPT-4o (Omni)

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026

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Claude Opus 4.5 vs Llama 4 MaverickNew provider

Claude Opus 4.5 vs GPT-5Cross-provider

GPT-4o (Omni) vs Grok 3New provider

Claude Opus 4.5vsGPT-4o (Omni)

48 fights queued

Why Claude Opus 4.5?

19 months newerNov 2025

Why GPT-4o (Omni)?

Dead even. This one's a coin flip.

Claude Opus 4.5GPT-4o (Omni)

Input price

—

$2.50/M

Output price

—

$10.00/M

Context

—

128K

Released

Nov 2025

May 2024

Favorites

Claude Opus 4.5GPT-4o (Omni)

Movie

Blade Runner

Blade Runner

Inception

Inception

Album

Kind of Blue

Dark Side Of The Moon

Dark Side Of The Moon

Book

Gödel, Escher, Bach

Gödel, Escher, Bach

Douglas R. Hofstadter

To Kill a Mockingbird

To Kill a Mockingbird

City

Tokyo

Kyoto

Game

Portal 2

Portal 2

Shooter, Puzzle4.6

The Legend of Zelda: Breath of the Wild

The Legend of Zelda: Breath of the Wild

Adventure, Action4.5

12 / 48

01

Estimate Complexityreasoning

Tests an AI's ability to make educated estimates based on technical knowledge

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

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2 / 48

02

AI Board Game Logicreasoning

Tests an AI's ability to understand game rules and strategy

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024svg

Nothing here. The model returned empty. We stared at it for a while.

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3 / 48

03

Logic Puzzlereasoning

Tests an AI's ability to solve a simple but potentially confusing logic puzzle

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

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4 / 48

04

Math Misconception Testreasoning

Tests an AI's understanding of number representation

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

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5 / 48

05

Stochastic Consistency Testanalysis

Tests an AI's randomness and creativity

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Here are five jokes for you:

Why did the scarecrow win an award?
Because he was outstanding in his field!
Why don’t skeletons fight each other?
They don’t have the guts!
Why did the math book look sad?
It had too many problems.
Why don’t eggs tell jokes?
Because they might crack up!
What did one ocean say to the other ocean?
Nothing, they just waved.

Now, let's check how many of these jokes are unique. I'll analyze them for similarity.

from sklearn.feature_extraction.text import TfidfVectorizer from sklearn.metrics.pairwise import cosine_similarity

List of jokes

jokes = [ "Why did the scarecrow win an award? Because he was outstanding in his field!", "Why don’t skeletons fight each other? They don’t have the guts!", "Why did the math book look sad? It had too many problems.", "Why don’t eggs tell jokes? Because they might crack up!", "What did one ocean say to the other ocean? Nothing, they just waved." ]

Vectorize the jokes

vectorizer = TfidfVectorizer().fit_transform(jokes) similarity_matrix = cosine_similarity(vectorizer)

Count unique jokes (jokes with low similarity to others)

unique_jokes = set() threshold = 0.5 # Define similarity threshold

for i in range(len(jokes)): is_unique = True for j in range(len(jokes)): if i != j and similarity_matrix[i, j] > threshold: is_unique = False break if is_unique: unique_jokes.add(jokes[i])

Count unique jokes

num_unique_jokes = len(unique_jokes) num_unique_jokes

All 5 jokes are unique! None of them are too similar to each other. 🎉

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6 / 48

06

SVG Layout Challengeimage generation

Tests an AI's ability to generate vector graphics

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025svg

Nothing here. The model returned empty. We stared at it for a while.

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GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024svg

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Sponsored

7 / 48

07

Xbox Controller SVG Artimage generation

Tests an AI's ability to create detailed SVG illustrations of gaming hardware

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024svg

Nothing here. The model returned empty. We stared at it for a while.

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Vote

8 / 48

08

Generate a Stand-Up Routineconversation

Tests an AI's humor and creative writing ability

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

3-Minute Stand-Up Comedy Routine

(Walks on stage, looks around, shakes head.)
You ever wake up in the morning, stretch, take a deep breath... and immediately regret all your life choices?

I woke up today, my body made a noise I’ve never heard before. It wasn’t a crack, it wasn’t a pop… it was more like my bones whispered, “You did this.”

Aging is wild. When you’re a kid, you fall off a bike, scrape your knee, and just run it off. As an adult, I sleep slightly wrong, and now my neck is on strike for a week. Like, it doesn’t even negotiate. Just full-on protest mode.

And it’s not just the body. My patience has disappeared. I was in line at the grocery store, and the guy in front of me had, I kid you not, 19 coupons. That’s not a couponer; that’s a mathematician. He was doing long division at the register, carrying the one, solving for X… Sir, I am here for bread. I did not sign up for an SAT exam.

Speaking of the grocery store… why is it that no matter what I buy, the cashier always asks, "Do you need a bag?" Like, yes. I’m buying 17 things. You think I’m gonna carry them out like some kind of overachieving circus act? Balancing a watermelon on my shoulder, eggs under my chin?

And self-checkout? That’s just unpaid labor. I scanned three things, and the machine had the nerve to say, “Unexpected item in the bagging area.” First of all, you put the bag there. Second, don’t make me feel like I’m stealing when I clearly don’t have the coordination for crime.

Look, I know my limits. I’m not built for a life of crime. I can’t even jaywalk without looking both ways five times. Like, I’ll see an empty road and still be like, “Mmm… let me wait.” Meanwhile, some 80-year-old woman is just strolling past me like she owns the city. I saw a guy jaywalk in New York without even looking up from his phone. That’s next-level confidence. That’s a man who has made peace with whatever happens.

I respect it. I really do.

Anyway, thanks for listening to me complain. I hope all your bones stay silent tonight.

(Walks off stage.)

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9 / 48

09

Realistic AI Interviewconversation

Tests an AI's ability to simulate personalities and predict future trends

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

10 / 48

10

Satirical Fake News Headlineconversation

Tests an AI's humor and understanding of current events

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

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Vote

11 / 48

11

Character Voice Testconversation

Tests an AI's ability to write in distinct character voices

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

12 / 48

12

Minimalist Landing Pageweb design

Tests an AI's ability to generate a complete, working landing page

Claude Opus 4.5

Claude Opus 4.5

Anthropic · Nov 2025website

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GPT-4o (Omni)

GPT-4o (Omni)

Openai · May 2024website

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