What data shapes can I generate?

Three templates are available — users (with name, email, role, city), products (with SKU, price, stock, rating) and blog posts (with title, author, views, slug). Each record uses realistic randomized values.

Are the IDs and UUIDs valid?

Yes. Numeric IDs increment from 1 and UUIDs are generated with the browser's crypto API, so they are unique and well-formed for use in tests.

Can I get a single object instead of an array?

Yes. When you generate one record you can choose whether to wrap it in an array or output a bare object, depending on what your endpoint expects.

Will the data look the same each time?

No. Values are randomised on each generation — names, cities, prices and UUIDs change — while numeric IDs increment from 1, so every batch is fresh but well-structured.

Are the email addresses real?

No. Emails are built from the random name plus placeholder domains like example.com and demo.io, so they are safe, non-routable test addresses.

Is any data sent to a server?

No. All records are generated in your browser. Nothing is uploaded, so it is safe for prototyping and offline use.

Mock JSON Generator — Gera Tools

This tool generates formatted, realistic mock JSON records for stubbing an API, seeding a UI, or writing tests. It produces ready-to-paste data for users, products and blog posts without any backend.

How it works

Pick one of three templates and the generator builds that many records by drawing random values from curated lists (names, cities, roles, product words) and computed fields:

user — id, uuid, firstName, lastName, email, city, role
product — id, name, SKU, price, stock, rating
post — id, title, author, views, slug

Numeric IDs increment from 1 so they stay unique, and UUIDs are produced with the browser’s secure crypto.randomUUID() so they are well-formed. You choose the record count and whether a single record is wrapped in an array.

Example

Generating one user record produces JSON like:

{
  "id": 1,
  "uuid": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
  "firstName": "Maya",
  "lastName": "Patel",
  "email": "[email protected]",
  "city": "Lisbon",
  "role": "editor"
}

Template	Key fields
user	name, email, role, city
product	SKU, price, stock, rating
post	title, author, views, slug

All records are generated in your browser, so your test data never leaves your machine.