Is ChatGPT-4.5 Better Than OpenAI o3?

In early 2025, OpenAI unveiled two significant models: GPT-4.5 and the O3 series. While GPT-4.5, codenamed “Orion,” represents an advancement in conversational AI, the O3 models are designed for complex reasoning and problem-solving tasks. This article delves into the capabilities, performance, and applications of both models to determine which stands out in the current AI landscape.

What is GPT-4.5

GPT-4.5 was released on February 27, 2025, initially available to ChatGPT Pro users and developers through the OpenAI API. Plans were set to expand access to ChatGPT Plus and Team users shortly thereafter .

Key Improvements

GPT-4.5 builds upon its predecessor, GPT-4, with several notable enhancements:

• Expanded Context Window: Supports up to 128,000 tokens, allowing for more extensive and coherent conversations .
• Multimodal Capabilities: Introduces support for image processing, enabling users to upload and analyze images alongside text .
• Improved Emotional Intelligence: Offers more human-like interactions by better understanding and responding to emotional cues .
• Reduced Hallucination Rate: Demonstrates a 37.1% reduction in generating incorrect or fabricated information compared to previous models .

Limitations

Despite these advancements, GPT-4.5 has its drawbacks:

• Cost: At $75 per million input tokens and $150 per million output tokens, it is significantly more expensive than models like GPT-3.5 Turbo .
• Reasoning Challenges: Some users report that GPT-4.5 struggles with complex reasoning tasks and may not consistently follow detailed instructions .

What is O3

OpenAI’s O3 model series represents a shift towards AI systems capable of advanced reasoning. Utilizing reinforcement learning, O3 models are trained to “think” before generating responses, employing a “private chain of thought” to plan and reason through tasks .

Key Features of OpenAI o3

1. Enhanced Reasoning Abilities

At the core of o3’s design is its ability to perform step-by-step logical reasoning. This is achieved through a “private chain of thought” mechanism, allowing the model to deliberate internally before generating responses. Such a feature enables o3 to tackle complex tasks in mathematics, coding, and scientific analysis with improved accuracy .

2. Superior Benchmark Performance

o3 has demonstrated remarkable performance across several benchmarks:

• GPQA Diamond: Achieved an 87.7% score on expert-level science questions .
• SWE-bench Verified: Scored 71.7% in solving real-world software engineering tasks, surpassing o1’s 48.9% .
• Codeforces: Attained an Elo rating of 2727, indicating high proficiency in competitive programming challenges .
• ARC-AGI Benchmark: Demonstrated three times the accuracy of o1 in abstract reasoning tasks .

3. Multimodal Capabilities

Beyond text, o3 exhibits strong visual perception skills. It can analyze images, charts, and graphics, making it adept at tasks that require interpreting visual data .

4. Autonomous Tool Use

o3 is equipped with the ability to autonomously utilize tools such as web browsing, Python execution, image generation, and file analysis. This allows the model to perform multifaceted tasks without explicit user prompts, enhancing its versatility .

5. Deliberative Alignment for Safety

To ensure reliable and safe outputs, o3 incorporates a deliberative alignment approach. This method enhances the model’s capacity to adhere to safety guidelines through a structured reasoning process .

6. Variants for Diverse Needs

OpenAI has released o3 in multiple versions to cater to different requirements:

• o3-mini: A smaller, cost-effective model optimized for speed and precision in technical domains .
• o3-mini-high: A variant of o3-mini that allocates more computational resources for enhanced reasoning, available to paid subscribers .

Considerations and Limitations

While o3 showcases significant advancements, it is not without challenges:

• Increased Computational Demand: The model’s deliberative processes require more computing power, leading to higher operational costs and potential latency in responses .
• Unpredictability in Outputs: Despite improvements, o3 can exhibit inconsistencies, such as hallucinations or errors in certain tasks, reflecting the broader challenges in AI development .

Comparative Analysis: GPT-4.5 vs. O3

Natural Language Processing and Creativity

ChatGPT-4.5 excels in generating creative and contextually rich responses, making it ideal for applications in storytelling, customer service, and strategic planning. Its enhanced emotional intelligence allows for more nuanced interactions.

In contrast, OpenAI o3 prioritizes logical reasoning over creative expression. While it may not match ChatGPT-4.5 in conversational flair, its structured approach ensures accuracy in tasks requiring detailed analysis.

Reasoning and Problem-Solving

OpenAI o3 outperforms ChatGPT-4.5 in technical domains. Its ability to deliberate internally results in higher accuracy in coding, mathematics, and scientific problem-solving. For instance, o3 scored 71.7% on the SWE-bench Verified benchmark, assessing software engineering capabilities.

ChatGPT-4.5, while competent, may not match o3’s precision in these areas. Its strengths lie more in general knowledge and creative tasks than in specialized technical problem-solving.

Cost and Accessibility

ChatGPT-4.5 is positioned as a premium offering, with costs of $75 per million input tokens and $150 per million output tokens.The pricing reflects its advanced capabilities but may be prohibitive for some users. Access is currently limited to ChatGPT Pro subscribers and enterprise clients, with broader availability planned.

O3 is positioned as a premium offering, with costs of $10 per million input tokens and $40 per million output tokens,$2.5 per million Cached input,its focus on computational efficiency suggests a more cost-effective solution for tasks requiring logical reasoning. Its design aims to balance performance with resource utilization, potentially offering a more accessible option for technical applications.

Conclusion: Choosing the Right Model

The decision between GPT-4.5 and O3 depends on the specific needs of the user:

• For Natural Conversations: GPT-4.5 is preferable for applications requiring human-like interaction and emotional intelligence.
• For Complex Reasoning Tasks: O3 is better suited for tasks involving advanced problem-solving, coding, and scientific research.

As AI continues to evolve, the integration of conversational fluency and deep reasoning in future models may bridge the gap between GPT-4.5 and O3, offering comprehensive solutions across various domains.

Getting Started

Developers can access GPT-4.5 API and O3 API through CometAPI. To begin, explore the model’s capabilities in the Playground and consult the API guide for detailed instructions. Note that some developers may need to verify their organization before using the model.

GPT-4.5 API and O3 API  Pricing in CometAPI，20% off the official price: