Gemini generates unstructured text by default, but some applications require structured text. For these use cases, you can constrain Gemini to respond with JSON, a structured data format suitable for automated processing. You can also constrain the model to respond with one of the options specified in an enum.
Here are a few use cases that might require structured output from the model:
- Build a database of companies by pulling company information out of newspaper articles.
- Pull standardized information out of resumes.
- Extract ingredients from recipes and display a link to a grocery website for each ingredient.
In your prompt, you can ask Gemini to produce JSON-formatted output, but note
that the model is not guaranteed to produce JSON and nothing but JSON.
For a more deterministic response, you can pass a specific JSON schema in a
responseSchema
field so that Gemini always responds with an expected structure.
This guide shows you how to generate JSON using the
generateContent method through the SDK
of your choice or using the REST API directly. The examples show text-only
input, although Gemini can also produce JSON responses to multimodal requests
that include images,
videos, and audio.