OpenAI Is Leaning on Paid Users to Test ChatGPT-4.5

In a livestream today, OpenAI finally announced the launch of its GPT-4.5 model, but with a twist: For now, using it requires a $200 per month ChatGPT Pro subscription.

That’s because the new large language model, or LLM, is still technically in a “research preview” state. This is all apparently shorthand for “please pay us for the privilege of being a beta tester.”

Jokes aside, the company is promising GPT-4.5 provides more “natural conversation,” and performs better when it comes to programming, pattern recognition, writing, and “solving practical problems.”

Note that GPT-4.5 isn’t intended as a reasoning model, meaning it won’t have the self-correcting or deep research capabilities of OpenAI o1, o3-mini, or the upcoming full version of o3. In a leaked document, the company said it’s not considering GPT-4.5 a “frontier” model, but it is OpenAI’s largest LLM yet, which should make it ideal for everyday queries, as the large database of training material should make for quicker answers.

In internal tests, OpenAI says the new model hallucinated about 24.7% less frequently than GPT-4.0, and was about 34.3% more accurate. Around 57% of internal human testers reportedly preferred GPT-4.5 to 4.0.

In other words, GPT-4.5 isn’t exactly at the cutting edge of AI, but it should be an improvement on other non-reasoning models, providing a nice middle ground between cheaper, more traditional LLMs and their frequently paywalled successors. The only major omissions seem to be multimodal features like AI Voice Mode and video input, although OpenAI says its working on updating its user experience, which seems to hint some version of these capabilities might come to the model in the future.

That makes sense, given that, once again, this is technically an early release, with OpenAI saying it’s “still exploring” GPT-4.5’s limits and how people can use it. To that end, the LLM is set to expand to all paid ChatGPT plans over the next two weeks, before presumably reaching free users as a replacement for GPT-4.0 once it leaves its preview state.