# Test data generator

> Generate realistic, reproducible sample data and export it as JSON or CSV, in your browser, nothing uploaded.

The test data generator produces realistic, reproducible sample rows — names, emails, addresses, prices, order statuses and more — and exports them as JSON, CSV, tab-delimited or Excel.

Also: test data generator, fake data generator, mock data generator, sample data generator, synthetic data generator, csv test data, dummy data generator, random data generator, faker online, generate sample json.

## What it does

Seeding a database, filling a staging environment or building a fixture all need data that looks real without being real. This generates it from 40 field types across seven categories, and does so deterministically: the same columns and row count produce the same values every time, so a fixture stays stable across runs instead of churning your diffs. Values within a row are also coherent — the email matches the name rather than being drawn independently.

## When to use it

- You need to seed a development or staging database with plausible records.
- You want a fixture file for tests that stays identical between runs.
- You are building a UI and need enough rows to see how it behaves when full.
- You need a CSV of sample records to import into another system.
- You want realistic data without using real customer records.

## What you give it

| Input | Meaning |
| --- | --- |
| Prompt | Describe the rows you want in plain language. Field types are matched by keyword, and a row count is picked up from phrasing like "500 rows". |
| Fields | Or choose columns by hand, naming each one and picking its type. |
| Row count | Up to 10,000 rows. Defaults to 25. |
| Format | CSV, JSON, tab-delimited or Excel. |

## What you get back

| Output | Meaning |
| --- | --- |
| Generated rows | A table of values you can review before exporting. |
| Export file | Copy the JSON or download the chosen format. |

## How it works

- Each value is derived by hashing the row index together with the column key, so generation is deterministic rather than random — the same inputs always produce the same output.
- Name-derived columns share one identity per row, so full name, first name, last name, email and username all agree with each other instead of being generated independently.
- Other columns mix their own key into the row seed, so two columns of the same type hold different values while each stays stable.
- A prompt is matched against field-type keywords, and falls back to an id, full name and email when nothing matches.

## Key terms

- **Deterministic generation** — the same inputs always yield the same output. This is what separates a fixture you can commit from random data that changes every run and makes tests flaky.
- **Referential coherence** — values inside a row agreeing with each other — the email derived from the name rather than drawn at random. Incoherent rows are obvious to anyone reviewing a demo.
- **Synthetic data** — data generated to resemble real records without originating from them, so it carries no privacy obligation and can be shared freely.

## Questions

### How many field types are available?

40, grouped into seven categories: personal, address and geo, internet, finance, business, commerce, and developer.

### Is the data random?

No, it is deterministic. The same columns and row count produce the same values every time, which is what makes it usable as a committed fixture. Regenerating with a new salt gives you a fresh set.

### How many rows can I generate?

Up to 10,000. The default is 25.

### What formats can I export?

CSV, JSON, tab-delimited and Excel.

### Is the generated data safe to use in a shared environment?

It is synthetic — assembled from name, place and product word lists rather than derived from real people — so it carries none of the privacy obligations real customer data would.


## Privacy

Generation runs entirely in your browser. Nothing is uploaded, nothing is stored, and no account is needed — the rows exist only in the page until you copy or download them.

## Links

- [Use the tool](https://www.postman.com/tools/test-data-generator) — the interactive version of this page.
- [Postman Tools](https://www.postman.com/tools) — every free tool in this set.
- [Dynamic variables docs](https://learning.postman.com/docs/tests-and-scripts/write-scripts/variables-list/) — Postman documentation.