Introducing GPT-4.5: OpenAI’s Latest Leap in AI Language Models

28-02-2025

On February 27, 2025, OpenAI unveiled GPT-4.5, their most advanced and computationally intensive AI language model to date. This powerhouse marks a significant evolution in scale and refinement, delivering deeper knowledge, fewer hallucinations, and smoother conversations. Initially launched for ChatGPT Pro subscribers at $200/month and developers on paid API tiers, GPT-4.5 blends cutting-edge capabilities with a premium price tag. In this guide, we’ll explore GPT-4.5 features, API pricing, benchmark performance, and comparisons with predecessors like GPT-4, GPT-4o, o3-mini, and competitor DeepSeek.

What Makes GPT-4.5 Stand Out?

GPT-4.5 is OpenAI’s latest milestone in scaling AI language models with massive datasets and computational power. Unlike reasoning-focused experimental releases, it refines the traditional GPT architecture, emphasizing broad knowledge and conversational excellence. Here’s what defines GPT-4.5:

• Unmatched Knowledge Depth: Trained on vast resources, GPT-4.5 masters intricate details across domains—history, science, and beyond—with encyclopedic precision, as early users note.
• Enhanced Reliability: Tackling the hallucination problem head-on, OpenAI claims GPT-4.5 significantly reduces fabricated answers, making it a trusted tool for research and professional tasks.
• Superior Emotional Intelligence: Excelling at tone and context, GPT-4.5 crafts empathetic, tailored responses—perfect for heartfelt letters or witty code debugging.
• Versatile Features: It offers web search for real-time info, file processing (PDFs, images, text), and ChatGPT canvas integration for collaborative editing. Note: Advanced Voice Mode remains exclusive to prior models.

As a “research preview,” GPT-4.5 rolls out to Pro users now, with Plus/Team access next week and broader availability later. It’s OpenAI’s final push in traditional scaling before GPT-5 shifts to reasoning.

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GPT-4.5 API Pricing: Premium Power Unveiled

The GPT-4.5 API pricing reflects its immense resource demands. Here’s how it stacks up against other OpenAI models:

Model	Input (per 1M tokens)	Cached Input (per 1M tokens)	Output (per 1M tokens)
GPT-4.5	$75.00	$37.50	$150.00
o1	$15.00	$7.50	$60.00
GPT-4o	$2.50	$1.25	$10.00
o3-mini	$1.10	$0.55	$4.40

• GPT-4.5 Pricing Details: At $75 per million input tokens and $150 per million output tokens, it’s a premium tier. Cached inputs drop to $37.50, a perk for repetitive tasks, yet it’s a leap from GPT-4o’s $2.50/$10.00.
• Why the High Cost?: OpenAI hasn’t disclosed exact parameter counts, but the pricing suggests GPT-4.5 dwarfs GPT-4’s rumored 1.8 trillion parameters, requiring immense server resources. Some X users speculate it could be a "mixture of experts" hybrid, though OpenAI remains tight-lipped.

Critics on X call it “too pricey for indie devs,” while fans argue it’s worth the innovation. OpenAI may tweak pricing later, but for now, GPT-4.5 API targets enterprises and researchers.

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GPT-4.5 Benchmark Performance: Strengths and Gaps

OpenAI’s GPT-4.5 benchmark performance blends new tests with older data, comparing it to GPT-4o, GPT-4, and o3-mini:

Benchmark	GPT-4.5	GPT-4o	GPT-4	o3-mini
GPQA (science)	71.4%	53.6%	-	79.7%
AIME ‘24 (math)	36.7%	9.3%	-	87.3%
MMMLU (multilingual)	85.1%	81.5%	84%*	81.1%
MMMU (multimodal)	74.4%	69.1%	-	-
SWE-Bench Verified (coding)	38.0%	30.7%	82%*	61.0%

Note: GPT-4 scores for MMMLU and SWE-Bench are from earlier MMLU (language) and HumanEval data, adjusted for context. Dashes indicate unavailable data for newer benchmarks.

• Strengths: GPT-4.5 excels in multilingual (85.1%) and multimodal (74.4%) tasks, with solid coding at 38%.
• Weaknesses: It trails o3-mini in math (36.7% vs. 87.3%) and science (71.4% vs. 79.7%), while GPT-4 leads in coding (82%*).

GPT-4.5 prioritizes breadth over deep reasoning, with reduced hallucinations as a key win.

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GPT-4.5 vs. DeepSeek API: A Head-to-Head Comparison

How does GPT-4.5 stack up against the budget-friendly DeepSeek API?

Feature	OpenAI GPT-4.5 API	DeepSeek API
Model Options	gpt-4.5, gpt-4o, etc.	deepseek-reasoner, deepseek-chat
Cost & Rate Limits	$75/$150 per 1M tokens	$5-$10 per 1M tokens (est.)
Hallucinations	Low	Moderate
Extras	Web search, uploads, canvas	Basic chat only
SWE-Bench (coding)	38.0%	~35% (est.)

• Cost Comparison: DeepSeek’s $5-$10 per million tokens is 10-15x cheaper than GPT-4.5’s $75/$150.
• Performance Edge: GPT-4.5 shines with extras and depth; DeepSeek competes in reasoning and coding (~35% SWE-Bench) at a fraction of the cost.
• Use Cases: GPT-4.5 suits feature-rich apps; DeepSeek fits budget builds.
• Vs. GPT-4o: GPT-4.5 offers 5-10% better performance and fewer hallucinations, but at a higher price.
• Vs. GPT-4: Sharper outputs at 2.5x the cost.
• Vs. Competitors: Claude 3.5 edges out in reasoning (e.g., math), while DeepSeek undercuts on price. GPT-4.5’s scale and ecosystem (web search, canvas) remain its trump cards.

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Final Thoughts on GPT-4.5

OpenAI GPT-4.5 is a massive upgrade—smart, smooth, and pricey. It’s ideal for ChatGPT Pro users and developers seeking top-tier AI language models. Yet, its uneven benchmark performance and high API pricing spark debate: Is scale the future, or will reasoning-focused models like GPT-5 take over? For now, GPT-4.5 feels like a costly capstone to OpenAI’s scaling era.

What’s your take on GPT-4.5? Too expensive, or worth the hype?
Stay tuned for more AI related content and tutorials. Hit me up on my socials and let me know what you think, I’m always up for a good tech convo.

Note: This blog is based on OpenAI’s official release.

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