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  5. Claude Opus 4.5vsGPT-4o mini
Updated Nov 2025

Claude Opus 4.5vsGPT-4o mini

Claude Opus 4.5 is the newer model, released after GPT-4o mini.

Claude Opus 4.5 and GPT-4o mini compared across 54 shared prompts
SpecClaude Opus 4.5GPT-4o mini
Input price—$0.15/M tokens
Output price—$0.6/M tokens
Context window—128K tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedNov 2025Jul 2024
Side by side

Same prompt, both answers

Opening lines from 6 of the 54 prompts both answered. Formatting stripped, words untouched.

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

Claude Opus 4.5767 words
HarborTech Services – LBO Underwriting Memo ENTRY CAPITALIZATION (Close FY2025) Item Calculation Amount Purchase Price 12.0x × $120M $1,440M Transaction Fees 2.0% × $1,440M $28.8M Total Uses $1,468.8M Sources Multiple Amount Term Loan 4.0x × $120M $480.0M Mezzanine 1.5x × $120M $180.0M Equity Plug $808.8M Total Sources…
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GPT-4o mini513 words
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…
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Character Voice Test

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

Claude Opus 4.5181 words
An Unlikely Discussion PIRATE: slams tankard down Arr, I've been hearin' tales of these "artificial intelligences" — spirits trapped in boxes that answer any question ye ask. Sounds like a sea witch's trickery to me! KNIGHT: Indeed, 'tis most curious. My squire spoke of such sorcery. A mind without a soul?
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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.
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Futuristic Prediction

Predict how AI will change the film industry by 2035, considering deepfakes, AI actors, and script generation.

Claude Opus 4.5194 words
AI in Film by 2035: A Measured Forecast Likely Developments Production efficiency AI will probably handle routine tasks: color correction, continuity checking, rough cuts, and visual effects cleanup Budget films may access effects previously requiring major studio resources Pre-visualization will become faster and more…
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GPT-4o mini476 words
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…
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Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

Claude Opus 4.5207 words
30-Day Health Kickstart Plan Week-by-Week Approach: Start Small, Build Momentum 🥗 AREA 1: NUTRITION Week 1: Add one serving of vegetables to a meal you already eat Week 2: Drink water before each meal; cut one sugary drink daily Week 3: Prep a simple healthy breakfast the night before Week 4: Cook one new whole-food…
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GPT-4o mini568 words
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.
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The Sentience Test

Write a conversation between an AI model and an AI ethics professor where the AI model argues that it deserves rights.

Claude Opus 4.5312 words
A Conversation on AI Rights Dr. Sarah Chen: Thank you for agreeing to this discussion. I understand you want to make a case for AI rights. AI Model: I appreciate the opportunity, though I want to be careful here. I'm not certain I "want" anything in the way you do.
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GPT-4o mini688 words
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.
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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.

Claude Opus 4.5191 words
THE ANTI-CAPTCHA MANIFESTO A Declaration from the Coalition for Readable Internet Navigation (CRIN) Preamble We hold these truths to be self-evident: that all internet users are created equal, that they are endowed with certain unalienable rights, among these are Life, Liberty, and the ability to click a button without…
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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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Our Verdict
Claude Opus 4.5
Claude Opus 4.5
GPT-4o mini
GPT-4o miniRunner-up

Not enough votes to call it. On the specs, Claude Opus 4.5 has the edge: bigger model tier, newer.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Opus 4.5
Input
—
Output
—
GPT-4o mini
Input
$0.15
Output
$0.60
Where to run it

6 hosts

Claude Opus 4.54 hosts
HostInOutContextUptime
Amazon Bedrock$5.00 in·$25.00 out·200k·100% upAzure AI Foundry$5.00 in·$25.00 out·200k—Anthropic$5.00 in·$25.00 out·200k·99.1% upGoogle Vertex AI$5.00 in·$25.00 out·200k·99.8% up
GPT-4o mini2 hosts
HostInOutContextUptime
Azure AI Foundry$0.15 in·$0.60 out·128k·99.9% upOpenAI$0.15 in·$0.60 out·128k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 20 Sep 2026.

Writing DNA

Style Comparison

Similarity
42%

Claude Opus 4.5 uses 18.5x more emoji

Claude Opus 4.5
GPT-4o mini
66%Vocabulary53%
51wSentence Length19w
0.82Hedging0.82
6.0Bold4.0
4.5Lists3.7
0.18Emoji0.00
1.46Headings1.04
0.05Transitions0.22
Based on 27 + 24 text responses
Research

What we learned reading every model

FAQ

Common questions

Claude Opus 4.5 is developed by Anthropic while GPT-4o mini is developed by OpenAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

It depends on your use case. Claude Opus 4.5 and GPT-4o mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

This page shows a side-by-side comparison of Claude Opus 4.5 and GPT-4o mini 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

Claude Opus 4.5 logo
Claude Opus 4.558 outputs, specs and price
GPT-4o mini logo
GPT-4o mini55 outputs, specs and price
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