Simon Willison’s Weblog

o3-pro. OpenAI released o3-pro today, which they describe as a "version of o3 with more compute for better responses".

It's only available via the newer Responses API. I've added it to my llm-openai-plugin plugin which uses that new API, so you can try it out like this:

llm install -U llm-openai-plugin
llm -m openai/o3-pro "Generate an SVG of a pelican riding a bicycle"

It's slow - generating this pelican took 124 seconds! OpenAI suggest using their background mode for o3 prompts, which I haven't tried myself yet.

o3-pro is priced at $20/million input tokens and $80/million output tokens - 10x the price of regular o3 after its 80% price drop this morning.

Ben Hylak had early access and published his notes so far in God is hungry for Context: First thoughts on o3 pro. It sounds like this model needs to be applied very thoughtfully. It comparison to o3:

It's smarter. much smarter.

But in order to see that, you need to give it a lot more context. and I'm running out of context. [...]

My co-founder Alexis and I took the the time to assemble a history of all of our past planning meetings at Raindrop, all of our goals, even record voice memos: and then asked o3-pro to come up with a plan.

We were blown away; it spit out the exact kind of concrete plan and analysis I've always wanted an LLM to create --- complete with target metrics, timelines, what to prioritize, and strict instructions on what to absolutely cut.

The plan o3 gave us was plausible, reasonable; but the plan o3 Pro gave us was specific and rooted enough that it actually changed how we are thinking about our future.

This is hard to capture in an eval.

It sounds to me like o3-pro works best when combined with tools. I don't have tool support in llm-openai-plugin yet, here's the relevant issue.