Free Fake JSON Data Generator

The Fake JSON Data Generator is a free online tool that generate fake json test data with custom schemas. supports strings, numbers, dates, emails, and more. It runs entirely in your browser with no installation or sign-up needed.

String, number, boolean, date, email, phone, name, address, UUID, and Lorem ipsum text.

Yes — add nested object fields to create complex JSON structures.

Yes, completely free.

Yes, the Fake JSON Data Generator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Fake JSON Data Generator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Fake JSON Data Generator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

JSON output is a single pretty-printed array of objects with two-space indentation — every record sits inside one set of square brackets, which is ideal for pasting into a file, a mock server, or a fixture. JSONL (JSON Lines) puts one complete JSON object on each line with no wrapping array and no commas between records. That line-delimited shape is what many data pipelines, log processors, and bulk-import tools expect, because they can read and process one record at a time without loading the whole file into memory. Choose JSON when a tool or person needs to read the dataset as one structured document, and JSONL when you are streaming records or feeding a bulk loader. This generator offers both formats with a single toggle, so you can produce the same schema either way and copy or download whichever your workflow needs.

The uuid field type produces version-4 UUIDs, the random variant of the universally unique identifier standard. Each value follows the canonical 36-character pattern of eight, four, four, four, and twelve hexadecimal digits separated by hyphens, with a literal "4" marking the version position and the variant digit constrained to the 8, 9, a, or b range. Because the bits are drawn from your browser's random number generator, the chance of two generated IDs colliding is vanishingly small, which is exactly why v4 UUIDs are the common choice for primary keys, record identifiers, and request IDs in test data. All four preset templates use a UUID as their id field, so loading any preset gives you ready-made identifiers. Add a field of type uuid whenever you need realistic, unique keys rather than sequential numbers in your mock dataset.

The date field type outputs values in ISO 8601 calendar format, written as YYYY-MM-DD — for example 1998-04-23 — with no time component attached. Each date is picked at random from a window that starts on 1 January 1970 and runs up to the current day, so you get a realistic spread of past dates rather than every record sharing one timestamp. That variety is useful for testing how a table sorts chronologically, how a date filter behaves across decades, and whether your formatting handles older years correctly. The ISO ordering also sorts correctly as plain text, which keeps things predictable in spreadsheets and databases. If your schema needs a created or published timestamp, add a date field and give it a clear key name like createdAt; several built-in presets already include one so you can see the format in action immediately.

You set the volume with the record count field, which accepts any whole number from 1 up to 1000 in a single generation. Producing a larger batch is one of the main reasons to use mock data rather than hand-typing a record or two: generating a hundred or more rows at once reveals how a table paginates, whether long text values break your layout, and how a list performs when it is actually full. Everything is created locally by your browser, so even a thousand records generate instantly with no upload and no waiting on a server. If you need more than a thousand entries, generate a full batch, then run the tool again and append the additional output to your file. Set your desired count, choose JSON or JSONL, and generate the whole dataset in one click.

Four presets load a sensible schema instantly so you do not have to build one field by field. The User preset gives you a UUID id, name, email, phone, city, a createdAt date, and an active boolean flag. Product includes an id, name, price, an inStock flag, a lorem description, and createdAt. Order provides an orderId, customer, email, total, status, and orderDate. Blog Post covers an id, title, author, lorem content, a published flag, publishedAt, and a url. Each one is a realistic starting point for a common data model rather than a fixed template — after loading a preset you can rename fields, change types, add new ones, or nest an object inside a record to match your own structure exactly. Pick the closest preset, adjust it to fit your schema, then set a record count and generate.