The OpenAI o3 release might not feel as much of a leap forward as GPT-4, but it's crazy. It's the first model from OpenAI that ticks more boxes than misses after GPT-4.

It's capable, multimodal, and insanely agentic. It writes better and has a good personality (like GPT-4.5). Unlike Claude and Gemini, OpenAI targets a much wider audience than the dev market.

I have been using Gemini 2.5 as my go-to model, and it's been really great, so I compared o3, Gemini 2.5, and o4-mini side-by-side.

Here are some observations

Where does O3 lead?

• It's the state-of-the-art in terms of raw IQ. The model can reason really well, but I wish Openai had made the raw reasoning trace public. I guess it's their trade secret.

• It has a better personality, unlike the previous OpenAI models; this model feels better to talk to. It's creative.

• Better multi-modality and tool-calling.

• Native image generation.

Where does Gemini 2.5 Pro lead?

• Gemini is cheap compared to o3 and performs similarly for most day-to-day tasks. For extensive use, if you're using API or not on Chatgpt pro, Gemini is a no-brainer.

• It codes better, Gemini produces better code and requires much less debugging. The packages it uses are more up-to-date than O3.

• One-million-context window compared to 200k in o3 and o4-mini.

• Less hallucination.

• Almost unlimited in comparison to the crazy openAI rate limits.

Where does o4-mini lead?

• It's slightly cheaper than Gemini 2.5 with almost as good reasoning, vision, and tool-calling ability. Through code generation, it was better with o3-mini-high.

For a side-by-side coding comparison, check out this blog: OpenAI o3 vs. Gemini 2.5 Pro vs. o4-mini: Coding comparison

OpenAI's positioning is interesting, while everyone is thinking in models, Sam is building the ultimate AI product, and I think they have succeeded. I always find myself returning to Chatgpt for the UX. None of the top labs is even closer in this regard. Though Gemini is still the best if you are not a Chatgpt pro user.

Would love to know your experience with O3 and how you like it as compared to Gemini 2.5?

I currently have Gemini Advanced subscription and I'm currently enjoying Gemini 2.5 Pro, it has become my daily driver having replaced Claude 3.7 Sonnet for me. The only thing is that I'm formerly someone who used ChatGPT heavily I feel that it would be wrong of me to write off ChatGPT when i have not really been able to use ChatGPT as advertised due to o1-pro, o3, and the full deep research being gated off with the pro subcription.

I want to know if the pro sub really is worth it? I'm trying to speed my up learning process on a couple of complex subjects and my biggest gripe with Gemini 2.5 Advanced is that it feels to sanitized sometimes meaning it will never try to posit anything aside from a very rigid understanding of the material. From what I have tried of the o3 model on POE it seems far more willing to try to break down concept / explore with you.

So I understand it can hallucinate more but I'm looking more for conceptual exploration as opposed to a very rigid task machine.

How would you all grade your experience with ChatGPT Pro?