Choose ChatGPT if you want a versatile assistant with a rich feature set, extensive integrations, and access to different functionalities like chat, images, and file analysis. It's ideal for general users and developers who need a comprehensive tool without the complexities of setting up their own models. However, avoid it if you need open weights or are searching for the lowest API costs.
On the other hand, if you're a developer seeking an easy way to work with open models, ollama is your go-to choice. It excels in simplicity and offers both cloud and local deployment options, making it suitable for teams that require access without the hassle of extensive setup. Just keep in mind it lacks a free tier and may have limitations for offline use, so it's not suited for those needing a no-cost solution or robust offline capabilities.