OpenAI has begun rolling out GPT-4.5, its newest and largest AI model, to ChatGPT Plus users. The rollout, which started on March 5, 2025, is expected to take 1-3 days, with rate limits subject to change as the company assesses demand.
GPT-4.5 represents OpenAI's most computationally intensive model to date, trained on an unprecedented scale of data and computing power. However, its performance on certain AI benchmarks falls short of newer 'reasoning' models from competitors like DeepSeek and Anthropic, as well as some of OpenAI's own models.
The model's size contributes to its high operational costs, leading OpenAI to reconsider its long-term availability through their API. Pricing for GPT-4.5 in the API is significantly higher than previous models, with input costs at $75 per million tokens and output costs at $150 per million tokens.
Great day to be a Plus user. pic.twitter.com/d4aIwCK0iq
— OpenAI (@OpenAI) March 5, 2025
Despite these challenges, OpenAI claims GPT-4.5 offers advantages such as:
- Deeper world knowledge
- Higher emotional intelligence
- Reduced frequency of hallucinations
The model has also demonstrated a notable ability to persuade other AI systems, particularly in scenarios involving financial transactions.
GPT-4.5 was initially made available to subscribers of OpenAI's $200-per-month ChatGPT Pro plan before expanding to the broader ChatGPT Plus user base. This phased rollout strategy allows OpenAI to manage the introduction of their most advanced model while monitoring its performance and user interaction in real-world applications.
