Few-shot prompting is a way of guiding an AI by showing it a few completed examples inside your request, so it follows the same pattern on the new item. You don’t describe the rules in detail; you demonstrate them, and the model picks up the format and tone from the samples.

Say you want product reviews sorted into “positive”, “neutral” or “negative”. Rather than writing a long instruction, you paste three reviews with their correct label, then a fourth with the label blank. The model fills in the blank by matching the pattern. That’s the whole trick, and it’s a staple of practical prompt engineering. It sits right next to zero-shot prompting, where you give no examples at all and rely on the model’s general knowledge.

Few-shot shines when the task has a specific shape that’s hard to put into words but easy to show. Pulling a date, an amount and a vendor out of messy invoices is a good case: two or three labelled examples teach the layout faster than a paragraph of rules. The same goes for matching a brand voice or a strict JSON schema.

There is a catch worth knowing. The examples eat into the prompt length the model can handle, so ten of them is not always better than three. Pick examples that cover the tricky edge cases, not ten near-identical easy ones, and keep their format identical so the model has nothing to second-guess. A messy or contradictory example set can actually make the output worse than no examples at all.

At TopDevs we use few-shot prompting to lock AI outputs into the exact format a client’s system needs, without the cost and delay of training a custom model.