Brain labTry it → read → next · ~8 min

Tutorials · Chapter C (3/4) · ~8 min

Structured outputs & JSON mode

Try it → see it → read → next

Force machine-readable replies — JSON fields your app can trust (and validate).

On paths: Builder · Professional · Student

Try yourself

Playground

Structured output lab

JSON schema when code consumes the answer — free text when humans read it.

App parses user tier from response

Recap

What you just did

You compared the same review as prose vs JSON — one is readable, one is parseable.

Teach

How it works

Structured output uses schema instructions or API features so the model returns JSON (or similar). Your code:

  1. Defines allowed keys and types
  2. Parses the response
  3. Validates before acting

Related to function calling — both return structured payloads, not essays.

Use it

When you'd use this

  • Routing tickets, extracting form data, building dashboards
  • Any time downstream code needs reliable keys

Watch out

Watch out

Always validate JSON in code. Retry or repair on parse errors. Never eval() model output.