Define the fields you want and get a prompt that makes ChatGPT, Claude, or Gemini return valid, parseable JSON every time — perfect for data extraction and wiring AI into apps. Free, private, no sign-up.
Analyze the input below and extract the requested fields.
Respond with ONLY a single valid JSON object in exactly this structure — no markdown code fences, no commentary, just the JSON:
{
"summary": "..." // one-sentence summary
"sentiment": "..." // positive, neutral, or negative
"keywords": ["...", "..."] // up to 5 key topics
}
Requirements:
- Output must be valid, parseable JSON and nothing else.
- Include every key exactly as written above; do not add extra keys.
- Use null for any value you cannot determine.
- Keep types consistent with the structure shown.
Input:
"""
{paste your input here}
"""Building with the API? Pro unlocks the full toolkit
You describe the task and define the fields you want back (name, type, description). It generates a prompt that instructs the model to return only a valid JSON object in that exact structure — ideal for extracting structured data or wiring AI into an app where you need parseable output.
Give the model an exact output structure, tell it to return only valid JSON with no markdown fences or commentary, list every key, and specify what to do for unknown values (use null). This tool builds a prompt with all of those instructions baked in. For production, also enable your provider's JSON/structured-output mode.
Yes, completely free with no sign-up. It runs entirely in your browser — nothing is uploaded.
Yes. The generated prompt is model-agnostic and works as a user or system message for any of them. Pair it with each provider's native JSON / structured-output / tool-calling feature for the most reliable results.
String, number, boolean, string array, and object — enough to describe most structured responses. Add a description to each field to guide the model on exactly what to put there.
Browse thousands of coding & developer prompts, or explore the full free toolkit.