The open-versus-closed decision isn’t ideological, it’s practical, and the right answer changes based on a small number of concrete factors specific to your project.
Start with data sensitivity. Strict residency or privacy requirements? Self-hosting an open-weight model removes the question of where your data goes entirely. Otherwise, a closed API’s convenience usually wins.
Factor in your actual infrastructure capacity. Running an open-weight model well requires real GPU infrastructure and expertise to manage it. Without that already, the operational overhead can easily exceed what you’d spend on a closed API.
Consider vendor lock-in risk. Closed APIs can change pricing, deprecate models, or shut down products entirely, as happened with Sora this year. An open-weight model you’ve already downloaded keeps working regardless of what the provider does next.
Check whether fine-tuning is actually a requirement. Open-weight models let you fine-tune directly on your own data, something closed APIs generally don’t allow. Most teams end up using both for different parts of their stack. See Terminal-Bench for results across both categories.
