What it is
The job it was built for, and the job it is not for.
GPT-4.1 Nano is a small, low-latency general model from OpenAI, positioned as the cheapest entry in the GPT-4.1 line. It is built for high-volume work that has to return quickly: classification, extraction, routing, tagging, first-pass summarisation over long documents. It is not the model to reach for when a task needs sustained reasoning or careful long-form writing, which is what its larger siblings are for.