Fake Data Generator for JSON mock data, schemas, fixtures, and demos
Build nested JSON fake data in the browser with a visual schema editor. Add fields, objects, arrays, nullable values, locale-aware Faker rules, custom enums, ranges, date formats, coordinates, and realistic domain values, then copy or download the generated JSON.
- Create structured JSON fake data instead of loose placeholder text
- Generate names, emails, addresses, dates, products, finance values, files, colors, network values, Git data, and more
- Use localized Faker data for English, Simplified Chinese, Traditional Chinese, French, German, Spanish, Japanese, Korean, Portuguese, and Russian
- Import and export generator configuration so a useful test data schema can be reused later
Fake Data Generator
Build structured JSON fake data with nested fields, arrays, locale-aware Faker rules, enums, ranges, nullable values, copy, JSON download, and reusable config import/export.
What this fake data generator supports
The tool is centered on JSON test data. You define the structure first, then assign realistic generation rules to each field.
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Visual JSON schema builder
Create root fields, nested objects, arrays, primitive values, nullable fields, and reusable field names without writing a schema file by hand.
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Large Faker rule library
Choose from person, contact, address, company, commerce, finance, date, image, color, file, Git, vehicle, airline, book, music, science, UUID, ULID, Nano ID, and text rules.
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Controlled values and ranges
Use fixed strings, fixed numbers, custom enum values, numeric min and max values, decimal precision, string length, word count, date formatting, and coordinate output formats.
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Locale-aware mock data
Switch locale when names, addresses, phones, companies, dates, and text should feel closer to a target market or interface language.
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Importable generator configuration
Export your schema configuration as JSON and import it later, which is useful for repeating the same API payload, fixture shape, or demo dataset.
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JSON copy and download
Generated data is shown as formatted JSON for review, copying, and download. The output is ready for mock APIs, seed scripts, tests, and documentation examples.
How to generate fake JSON data
The fastest workflow is to model the fields first, then tune rules only where the default output is not close enough.
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Set the number of rows and choose a locale for generated names, addresses, phones, companies, and text.
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Add root fields, then click a field to edit its JSON type: object, array, string, number, integer, boolean, or null.
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For arrays, choose the array length and item type. Object arrays can contain their own child fields.
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Pick a generation rule for each primitive field. Use enum, fixed value, range, length, word count, date, or coordinate settings when the value needs tighter control.
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Review the formatted JSON output, then copy it, download it, or export the configuration so the same fake data schema can be reused.
Useful details for realistic mock data
Small schema choices matter when fake data is used in tests, UI states, and backend contracts.
- Use nested objects for API responses that contain user profiles, shipping addresses, product metadata, billing details, or audit information.
- Use arrays for cart items, order lines, comments, permissions, tags, events, and related resources.
- Use custom enum values for status fields such as `pending`, `paid`, `cancelled`, `active`, `draft`, or `archived`.
- Use numeric ranges for prices, ports, coordinates, quantities, scores, limits, and pagination values.
- Use date formatting when the next system expects `yyyy-MM-dd`, `yyyy-MM-dd HH:mm:ss`, or another predictable date string.
- Use nullable fields to test empty states, optional profile fields, missing metadata, and partial API responses.
Common use cases
This page is most useful when realistic structured JSON can unblock UI work, API examples, QA fixtures, or documentation without touching production data.
After generating JSON fixtures, inspect formatting, nesting, and escaped values with the JSON Formatter before pasting the payload into docs, tests, or mock APIs. If the same sample data needs to move through spreadsheets or QA handoff, prepare that flow with CSV Tools so CSV and TSV rows stay easier to review.
API mock responses
Create JSON payloads for REST endpoints, frontend mocks, contract examples, API documentation, and local integration work.
Frontend UI states
Fill tables, cards, profiles, product lists, dashboards, search results, order screens, and empty-state tests with structured data that resembles a real app.
QA fixtures and seed data
Generate repeatable fixture shapes for automated tests, manual QA scripts, demo accounts, staging imports, and regression cases.
Privacy-safe examples
Replace customer records with synthetic names, emails, addresses, account-like values, and transaction-like data before sharing screenshots or docs.
Practical fake data guidelines
Good fake data should look believable enough to catch layout and validation issues, but it should never be mistaken for real customer data.
- Keep field names close to the API contract or database model you are testing.
- Avoid perfect data only. Include nullable fields, varied string lengths, long names, empty arrays, and mixed statuses.
- Use example email domains and synthetic finance values when data appears in screenshots, docs, or shared tickets.
- Export the configuration when the same fake data structure will be reused by multiple teammates or test runs.
- Keep generated passwords and card-like values out of real authentication or payment workflows.
- Use smaller row counts while designing the schema, then increase the count when the structure is stable.
Limits and privacy notes
Synthetic data is useful for development, but it has different guarantees from a production data generator or anonymization pipeline.
- The generated values are fake, but formats such as credit cards, IBANs, phone numbers, and addresses may still look realistic. Do not use them to represent real people.
- This tool creates JSON data. It does not validate a formal JSON Schema document or infer a schema from an existing API automatically.
- Locale support depends on the underlying Faker dataset, so coverage can vary by field and language.
- Browser generation is practical for mock data and fixtures. Very large datasets should be generated in a script or backend job.
- Synthetic data is not anonymization. Do not mix it with real customer records and assume the result is privacy-safe.
Frequently asked questions
Answers to common questions about usage, data handling, result checks, and practical limits.
01 Does the fake data generator send my schema or output to a server?
Does the fake data generator send my schema or output to a server?
No. The editor, generation process, copy action, and JSON download run in the browser.
02 Can I build nested JSON objects and arrays?
Can I build nested JSON objects and arrays?
Yes. You can add nested object fields, arrays of primitive values, and arrays of objects with their own child fields.
03 Can I reuse a fake data schema later?
Can I reuse a fake data schema later?
Yes. Export the generator configuration as JSON, then import it later to restore the schema, rules, locale, and row count.
04 Is this the same as a JSON Schema validator?
Is this the same as a JSON Schema validator?
No. This is a schema-style data builder for generating mock JSON. It does not validate against the JSON Schema specification.
05 What output format does it generate?
What output format does it generate?
The current output is formatted JSON. Use the generated JSON directly in mock APIs, fixtures, docs, tests, or seed scripts.
06 Can generated financial or identity-like values be used in production?
Can generated financial or identity-like values be used in production?
No. They are sample values for testing and demonstration. Real payment, identity, authentication, and compliance workflows need controlled production systems.
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