Mock data (or fake data) is placeholder information used for testing and development. It's designed to look like real data, so you can build and test applications without using sensitive user information.

Is my data kept private?

Yes, your data is 100% private. The tool runs entirely in your browser using JavaScript. Nothing you type is ever sent to our servers.

Mock Data & JSON Generator - Free Online Tool

Q: Why would I use a JSON generator?

A JSON generator saves time by creating realistic, structured data for prototyping APIs, testing front-end components, or populating a development database. It ensures you have consistent data to work with.

Q: How do I specify data types with parameters?

You can customize data types by passing parameters inside the parentheses, like `integer(18, 65)` for a number between 18 and 65, or `paragraph(5)` for a 5-sentence paragraph. The built-in cheatsheet lists all available types.

Q: Can I create nested JSON objects?

Currently, the tool generates a flat array of JSON objects. Each line in the schema defines a top-level key. Support for nested objects is being considered for a future update.

Tools

Mock Data & JSON Generator

Add to Favorites Remove from Favorites

Your Schema

Generated JSON

Data Type Helper

Insert

Generator Options

Number of Records

JSON Formatting

Pretty Print (Readable)

Download JSON Copy Clear Sample

About the Mock Data & JSON Generator

This tool is designed for developers, testers, and designers who need realistic, structured data for their projects. Instead of using real, sensitive data or spending hours creating test data by hand, you can define a simple schema and instantly generate any number of records in JSON format. It's perfect for populating a development database, testing an API, or creating mockups for a new application interface.

We designed it to be both powerful and easy to use. The simple `key: type()` syntax allows you to create complex data structures quickly, and the built-in cheatsheet makes discovering new data types simple. The entire process runs in your browser, so your schemas and data are always private.

How to Use the Tool

Define your data structure in the "Your Schema" editor. Use the format `fieldName: dataType()`.
Use the "Data Type Helper" to find and insert available data types like `fullName()` or `integer(18, 65)`.
Set the number of records you want to generate in the "Generator Options".
The tool will automatically generate the JSON on the right as you type.
Click "Load Sample" to see a pre-made schema with many different data types to get you started.

Frequently Asked Questions

What is mock data?

Mock data (or fake data) is placeholder information used for testing and development. It's designed to look and feel like real data, so you can build and test your applications without using sensitive user information. For example, instead of a real user's email, you would use a fake one like `jane.doe@example.com`.

Why would I use a JSON generator?

A JSON generator saves you a huge amount of time. It's essential for prototyping APIs, testing front-end components that need data to display, or populating a database for development. It ensures you have consistent, realistic-looking data to work with from the very beginning of a project.

How do I specify data types with parameters?

Many data types can be customized by passing parameters inside the parentheses. For example, to generate a random number between 18 and 65, you would use `integer(18, 65)`. To get a paragraph with 5 sentences, you'd use `paragraph(5)`. The built-in cheatsheet lists all available types and their parameters.

Can I create nested JSON objects?

Currently, this version of the tool generates a flat array of JSON objects. Support for nested objects and arrays is a feature we are considering for future updates. For now, each line in the schema defines a top-level key in each generated object.

Is the schema I create and the data I generate kept private?

Yes, 100%. This tool is powered by JavaScript and runs entirely within your web browser. Nothing you type—neither your schema nor the generated JSON—is ever sent to our servers. Your work is completely private and secure.