API JSON WorkbenchLocal-first tools for API data
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Local-first JSON tools

API JSON Workbench

Paste JSON once, then format, validate, compare, generate types, infer schema, and create mock data in a focused API developer workspace.

JSON FormatterFormat, validate, and minify JSON locally in your browser.JSON DiffCompare two API responses and inspect structural changes.JSON to TypeScriptGenerate TypeScript types from real API response samples.JSON Schema GeneratorInfer JSON Schema from sample payloads.Mock Data GeneratorCreate mock JSON that follows your API data shape.

Recent local history

Your payloads stay in this browser. Saved entries use IndexedDB and are never uploaded.

No local history yet. Format a JSON payload to create your first entry.