Clean · Convert · Repair & Generate
Format, repair, and transform JSON, SQL, and Markdown. Clean LLM output, generate Zod schemas, escape strings, and more — 100% private in your browser.
Popular tools
Fix malformed JSON automatically
Explore JSON structure in tree view
Generate Zod schemas instantly
Escape & unescape JSON strings
Beautify & pretty print JSON
Convert JSON to escaped string
Fix AI-generated JSON errors
Convert CSV data to JSON arrays
Convert tab-separated to comma-separated
Convert lists to comma-separated
Parse escaped JSON strings
Sanitize and format AI responses
Convert Markdown to semantic HTML
Why use FormatList for AI development?
FormatList is a free online AI developer toolkit designed for developers working with JSON, AI models, and data transformation. Every tool runs 100% in your browser — nothing is uploaded to any server.
AI developer workflows
- Fix AI output — ChatGPT, Claude, and Gemini sometimes produce invalid JSON. Our JSON Repair tool fixes trailing commas, single quotes, and missing brackets automatically.
- Generate schemas — Convert JSON objects to Zod schemas in one click. Save time writing TypeScript validation by hand.
- Clean stringified JSON — Parse escaped JSON strings from API logs, database exports, and LLM responses with automatic double-encoding detection.
- Sanitize LLM responses — Remove markdown wrappers, extra explanations, and formatting artifacts from AI-generated code.
Developer essentials
- JSON tools — Formatter, validator, repair, compare, escape, and Zod schema generation in one place.
- Data conversion — Convert newline-separated lists to comma-separated values, SQL IN clauses, JSON arrays, and more. CSV to JSON and TSV to CSV converters also available.
- Privacy first — All processing is client-side. Your data never leaves your browser.
AI Response Formatting — from messy to clean
Working with AI models like ChatGPT, Claude, and Gemini often means dealing with messy output. JSON wrapped in markdown code blocks, trailing commas, single quotes, and extra explanatory text can break your pipelines.
FormatList provides specialized tools to clean, parse, and validate AI-generated data:
- Repair ChatGPT JSON — Fix the most common JSON errors produced by large language models.
- Clean LLM Output — Strip markdown wrappers, explanations, and formatting artifacts.
- Extract JSON from Markdown — Pull JSON out of markdown code blocks automatically.
- AI Response Parser — Parse and structure mixed AI output into usable data.
Developer Workflow Automation
Modern development involves constant data transformation. Whether you are preparing API payloads, cleaning database exports, or formatting configuration files, FormatList streamlines your workflow with instant, browser-based tools.
JSON workflow
From formatting minified API responses to generating TypeScript Zod schemas, our JSON toolkit covers the full lifecycle of JSON data:
- Format — Beautify minified JSON with configurable indentation.
- Validate — Check syntax and catch errors before they hit production.
- Parse — Explore JSON structure with an interactive tree view of types and values.
- Repair — Auto-fix common corruption from AI models, logs, and copy-paste.
- Compare — Diff two JSON objects side by side.
- Escape — Prepare JSON strings for embedding in code or API calls.
- Stringify — Convert JSON objects to escaped string representations.
- Generate schemas — Convert JSON to Zod for runtime type safety.
- Convert — Transform CSV data to JSON arrays for API integration.
SQL workflow
Generate SQL IN clauses from lists of IDs, format SQL queries, and prepare data for database operations — all without leaving your browser.
Frequently asked questions
How do I repair broken JSON?
Use our JSON Repair tool. Paste invalid JSON and it automatically fixes trailing commas, single quotes, missing brackets, and unescaped characters. Works great for AI-generated JSON too.
How do I convert JSON to Zod schema?
Paste a JSON object into the JSON to Zod tool. It generates a complete TypeScript Zod schema with inferred types. Supports nested objects, arrays, optional fields, and enum detection.
How do I convert lines to comma separated values?
Paste your list into the converter below. The output updates instantly with comma separated values you can copy with one click. Switch between comma, SQL, JSON, Python, and Markdown formats.
How do I escape a JSON string?
Use the JSON Escape tool. Paste your JSON and toggle between escape and unescape modes. Perfect for preparing JSON for API calls, embedding in code, or extracting from logs.
How do I fix ChatGPT JSON output?
Use our Repair ChatGPT JSON or JSON Repair tools. They handle common LLM output issues like trailing commas, single quotes, unquoted keys, and markdown code block wrappers.
Is this tool really private?
Yes. All processing happens locally in your browser using JavaScript. No data is sent to any server, stored, or tracked. You can even use it offline after the first load.