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JSON Runs offline

Fake JSON Generator

Turn a one-line-per-field schema into an array of realistic fake JSON records, generated entirely in your browser.

Input

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Output

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Questions
What field types are supported?
integer, number, boolean, uuid, date, name, email, phone, company, and address - written one per line as "fieldName: type", for example "id: integer". Type names are case-insensitive.
How realistic is the generated data?
It is plausible-looking, not realistic. Names, companies, streets and cities are assembled from small built-in word lists (about 20 first names, 20 last names, a dozen streets/cities/company words), so with a large record count you will see repeats - this tool makes convincingly-shaped test data, not a demographic simulation. Phone numbers are random digits in a familiar format and are not real dialable numbers.
Is the UUID a real version-4 UUID?
Yes - it is the one precise-format claim this tool makes. The version nibble is forced to 4 and the variant bits to 10xx per RFC 9562, and the random bits come from crypto.getRandomValues rather than Math.random(), so the bit layout holds up if you check it.
What happens with a huge record count or a bad schema line?
The record count is clamped to 1-10,000 even if a permalink is hand-edited to request more. An unrecognized type, a line with no colon, or a line with no field name before the colon throws a specific error naming that exact line; a schema with no valid lines at all throws with an example line to copy.
        
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