OpenAI’s GPT-4o vs GPT-4.5: Speed, Accuracy, and API Strategy Compared
Image Credit: D Koi | Splash
OpenAI's progression in artificial intelligence models, with GPT-4o released in May 2024 and GPT-4.5 in February 2025, illustrates the company's strategy to advance language processing amid competition from firms like Anthropic and Google. These developments emphasize improvements in efficiency and capability, while navigating challenges such as resource allocation and model sustainability.
GPT-4o, unveiled on May 13, 2024, features integrated multimodal capabilities, processing text, audio, images and video through a single neural network. It provided responses up to twice as fast as GPT-4 Turbo, particularly in audio interactions. GPT-4.5, codenamed Orion, launched as a research preview on February 27, 2025, focusing on larger-scale training to boost accuracy and creative outputs. OpenAI discontinued GPT-4.5's API access on July 14, 2025, while retaining it in ChatGPT for subscribers, to shift resources toward newer models.
Background and Development
Founded in 2015 and restructured in 2019, OpenAI leverages Microsoft's Azure for training, supporting both GPT-4o and GPT-4.5. GPT-4o addressed latency in earlier audio handling, achieving 320-millisecond average response times via unified training. This met needs for smoother interfaces in consumer tools.
GPT-4.5 scaled data and compute to cut inaccuracies and enhance response naturalness, per early evaluations. Its debut followed Anthropic's Claude 3.5 Sonnet in June 2024, heightening sector competition. The API phase-out, announced April 14, 2025, stemmed from high costs, GPU constraints and latency concerns, enabling focus on efficient successors.
Key Features and Performance Comparison
Tests indicate GPT-4.5's strength in reasoning, with 71.4% on the Graduate-Level Science test, exceeding GPT-4o in depth. It shows reduced hallucination at 37.1% on PersonQA, versus GPT-4o's 61.8%. For programming and creativity, GPT-4.5 offers more refined results.
GPT-4o prioritizes speed and multimodality, launching at US$5 per million input tokens and US$15 output, reduced to US$2.50 input and US$10 output in August 2024. GPT-4.5 priced at US$75 input and US$150 output per million. It supports real-time voice, effective for varied inputs. Benchmarks affirm GPT-4.5's edge in complexity, GPT-4o's in efficiency.
GPT-4.5 excels in detailed knowledge for research, but its costs and scale hinder API use. GPT-4o delivers cost savings and versatility in languages and visuals, though it may lag in advanced logic.
Both face privacy and bias risks, mitigated via human feedback. GPT-4.5's deprecation reflects broader AI challenges in managing compute demands.
Impact on Users and Industry
GPT-4o enabled free ChatGPT tiers, aiding education and services. GPT-4.5 supported nuanced tools, but its API end prompted shifts to GPT-4.1, released April 14, 2025, disrupting some workflows.
This fosters hybrid models, urging rivals' innovations. Economically, AI may automate tasks while enhancing efficiency, varying by sector. Regulations like the EU AI Act stress transparency.
Future Trends in AI Model Evolution
OpenAI released o3-mini on January 31, 2025, and o3 with o4-mini on April 16, 2025, advancing reasoning from o1 precursors. These target multi-step tasks, signaling compact designs for efficiency.
Trends include ethical focus and supply chain management, with potential constraints from data and hardware into 2026.
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