TL;DROpen weights vs closed models is a core divide — control and privacy vs convenience and frontier quality.
Open-weight models (Llama, Mistral, Qwen) can be downloaded, run privately, fine-tuned, and audited — control, privacy, no per-token fee, but you handle infra and they often trail the absolute frontier. Closed models (Claude, GPT, Gemini) offer top capability via API with no ops burden, but you send data out, pay per token, and can't inspect or self-host. Choose by privacy, cost, control, and capability needs.
Key points
Open: run private, fine-tune, audit, self-host
Closed: top capability via API, no ops
Open = control/privacy; closed = convenience/frontier
Choose by privacy, cost, control, capability
Common mistakes
Sending sensitive data to a closed API when open fits
Assuming open weights match the frontier
Underestimating self-hosting ops cost
Try it: Pick open vs closed for a privacy-sensitive on-prem app.