Mock Data Generator

What it does

A free, privacy-first mock data generator for developers that creates coherent, reproducible datasets. Generate data using a field picker, a pasted JSON sample, or JSON Schema. Emails, locations, and timestamps stay logically consistent. Use a seed for identical output every time. Export unlimited JSON, NDJSON, or CSV. Runs entirely client-side, works offline, and requires no signup.

Free client-side mock data generator. Build a schema or paste a JSON sample to generate realistic, coherent JSON, NDJSON, or CSV. Seedable, no row cap.

Generate realistic, coherent fake JSON, NDJSON, or CSV — from a field picker, a pasted sample, or a JSON Schema. Everything runs in your browser. Infers a generator for each field from your keys and value patterns (a value like 42 for id stays an integer; a UUID string becomes a UUID), then generates more rows in the same shape. Load an example . Supports the common subset: type, properties, required, items, enum, format, minimum/maximum, minItems/maxItems . No OpenAPI or $ref yet. Load an example . What this mock data generator does This is a free, privacy-first tool for generating realistic test data without sending anything to a server. Unlike most generators, it focuses on coherence —…from jsondevtools.org

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