ChatGPT 4.5 vs ChatGPT 4o: Which Model Should You Use in 2025?

In this post, I’m going to compare two of OpenAI’s advanced ChatGPT models: GPT-4.5 and GPT-4o.
If you’re looking for a detailed comparison to decide which model fits your needs—whether it’s for creative writing, coding, or general AI tasks—you’ve come to the right place.
Because today, I’m going to break down ChatGPT 4.5 vs. 4o in terms of:

• Core capabilities and strengths
• Multimodal support
• Performance benchmarks
• Cost and efficiency
• Ideal use cases
• And more
  Let’s dive in!

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Introducing: The Two Models

In the blue corner, we have ChatGPT 4o.
ChatGPT 4o is OpenAI’s flagship multimodal model capable of processing text, audio, images, and video in real time. It’s fast, cost-efficient, and supports over 50 languages. It’s ideal for applications requiring rich multimodal interactions like visual communication and real-time assistance.

In the red corner, we have ChatGPT 4.5.
GPT-4.5 focuses on conversational expertise and natural language understanding. It excels in generating creative, coherent, and human-like text with enhanced emotional intelligence and better hallucination reduction. It’s larger and more compute-intensive than 4o and designed for content creation, writing assistance, and nuanced dialogue.

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Core Capabilities and Strengths

• ChatGPT 4o:
  • Native support for text, audio, image, and video inputs.
  • Fast response times with 50% reduced API costs compared to GPT-4 Turbo.
  • Strong multilingual capabilities and cutting-edge visual and audio understanding.
  • Great for real-time cross-modal applications and interactive assistants.
• ChatGPT 4.5:
  • Superior natural language generation with better prompt adherence and coherence.
  • Broader general knowledge base with a knowledge cutoff in mid-2024.
  • Lower hallucination rate (around 37%) and enhanced conversational nuance.
  • Optimal for creative writing, complex dialogue, and general knowledge tasks.

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Performance Benchmarks

• On MMLU (Massive Multitask Language Understanding), 4o scores 88.7%, outperforming many prior models.
• GPT-4.5 scores slightly lower on MMLU (85.1%) but offers better conversational capabilities.
• On coding benchmarks, GPT-4.5 excels in real-world coding tasks, though 4o matches performance on code generation with multimodal inputs.
• GPT-4.5 leads in emotional intelligence and long-context coherence, while 4o dominates in multimodal efficiency and speed.

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Cost and Efficiency

• ChatGPT 4o offers 50% cost reduction versus GPT-4 Turbo, making it more cost-effective for applications needing multimodal inputs.
• GPT-4.5 is more compute-intensive and has higher cost per token, generally offered for professional and research users requiring top-tier output quality.

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Ideal Use Cases

Use Case	Best Model
Multimodal interaction (text + image + video + audio)	ChatGPT 4o
Creative writing and storytelling	ChatGPT 4.5
Real-time conversational AI	ChatGPT 4.5
Coding and problem-solving	Comparable, with slight edge to GPT-4.5 in complex coding
Multilingual understanding	ChatGPT 4o
Cost-sensitive application	ChatGPT 4o

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Final Thoughts

• Use ChatGPT 4o if your projects require efficient multimodal AI with fast, cost-effective performance, especially for global and interactive applications.
• Use ChatGPT 4.5 if you prioritize superior natural language understanding, creative writing, and emotionally intelligent dialogue in your workflows.
• Both models represent state-of-the-art technology, and the best choice depends on your specific use case, budget, and environment.