Base64EncoderDecoder.com

Fake Data / Mock JSON Generator

Build a custom schema and generate realistic mock data — JSON, CSV, or SQL — instantly and privately in your browser.

Schema fields

0 chars · 1 lines

40+ field types

Names, emails, addresses, phones, IPs, UUIDs, dates, prices, credit cards, enums — pick exactly the shape you need.

JSON, CSV & SQL

Export as JSON array, JSON Lines (NDJSON), CSV (RFC 4180), or ready-to-run SQL INSERT statements.

Private & unlimited

All generation happens in your browser. No accounts, no row limits on free tiers, no data leaves your device.

When to use mock data

  • API development — seed a local database or stub a backend before the real one exists.
  • UI prototyping — fill tables, lists, and dashboards with realistic content instead of "Lorem ipsum".
  • Load & performance testing — generate thousands of records to stress test pagination, search, and rendering.
  • Demos & sales — show off a product with believable customer, order, or inventory data — no NDA risk.
  • QA test fixtures — produce deterministic-looking but synthetic datasets for Cypress, Playwright, or Jest.

Field types reference

The generator includes Faker-style providers grouped by category: Identity (UUID, names, email, username, password, avatar, phone), Business (company, job title, product, category, price, currency, Luhn-valid credit cards), Location (street, city, state, zip, country, lat/long), Internet (URL, domain, IPv4, IPv6, MAC, user agent, hex color), Primitives (boolean, integer/float with min-max ranges, ISO 8601 dates, Unix timestamps, custom enums), and Text (lorem-style word, sentence, paragraph).

Frequently asked questions

›What is a mock JSON generator?

A mock JSON generator creates realistic-looking but fake datasets — names, emails, addresses, IDs, prices, dates — that you can use to seed databases, test APIs, populate UI prototypes, and run load tests without exposing real user data.

›Is the fake data generator free?

Yes. The tool is 100% free, requires no sign-up, and has no API rate limits. Generation runs entirely in your browser using JavaScript and the Web Crypto API.

›How many records can I generate at once?

Up to 1,000 records per batch. For larger datasets, run multiple batches and concatenate the output, or download each batch as a separate file.

›Which output formats are supported?

JSON array, single JSON object, JSON Lines (NDJSON), CSV (RFC 4180-compatible), and SQL INSERT statements with a configurable table name.

›Can I define my own schema?

Yes. Add fields with custom names and pick from 40+ data types: UUID, name, email, phone, address, city, IP, MAC, date, integer, float, enum, credit card (Luhn-valid), and more. You can also start from a preset (Users, Products, Addresses, Companies).

›Is my schema or generated data sent anywhere?

No. Everything is generated locally in your browser. No schemas, fields, or output ever leave your device — perfect for sensitive or compliance-restricted environments.

›Are the credit card numbers valid?

Generated credit card numbers pass Luhn checksum validation and use real BIN prefixes (Visa, Mastercard, Amex), but they are NOT real cards and cannot be charged. They are intended for form validation testing only.

›How do I configure integer or enum ranges?

For integer and float types, enter a range like 10-500 in the options field. For enum, enter comma-separated values like active, inactive, pending — the generator picks one at random per record.

›Can I use the generated data commercially?

Yes. The output is synthetic and unrestricted. Use it for client demos, test fixtures, CI pipelines, load testing, sales presentations, or any commercial purpose.

›How is this different from Faker.js or Mockaroo?

This tool covers the most common Faker-style providers in a zero-install, zero-account, browser-based UI. Mockaroo runs server-side with row limits on the free tier; this generator runs entirely client-side with no quotas and no data egress.

More free developer tools

Part of our growing tool belt — all client-side, all free.

JWT Encoder & Token Generator

Generate and sign JSON Web Tokens (HS256/384/512) locally in your browser.

Open tool

Regex Generator

Build regular expressions visually with blocks, quantifiers, presets, and live match preview — all in your browser.

Open tool

Regex Tester & Debugger

Test regular expressions with real-time match highlighting, capture groups, and replacement preview — all in your browser.

Open tool