MockHero is a synthetic test data API that generates realistic, relational fake data for developers. It supports 156 field types, 22 locales, and outputs JSON, CSV, or SQL.

How do I generate test data with MockHero?

Send a POST request to /api/v1/generate with a JSON schema describing your tables and fields. You can also use plain English prompts or pre-built templates for common schemas like ecommerce, blog, or SaaS.

What field types does MockHero support?

MockHero supports 156+ field types including uuid, email, full_name, phone, address, company, credit_card, iban, ip_address, url, date, timestamp, price, latitude, longitude, color, avatar, paragraph, and many more.

Does MockHero support relational data?

Yes. Use ref fields to create foreign key relationships between tables. MockHero generates referentially consistent data across all related tables.

Can I use MockHero with AI coding agents?

Yes. MockHero provides an MCP (Model Context Protocol) server that works with Claude Desktop, Claude Code, Cursor, and other AI-powered development tools. Install it via npx @mockherodev/mcp-server.

Yes. The free tier includes 1,000 records/day, 100 records/request, all 156 field types, all 22 locales, and JSON output. Paid plans start at $29/month for higher limits and additional output formats.

What output formats does MockHero support?

MockHero outputs JSON (all plans), CSV (Pro and Scale), and SQL with dialect support for PostgreSQL, MySQL, and SQLite (Pro and Scale).

What locales does MockHero support?

MockHero supports 22 locales including en, de, fr, es, it, pt, nl, pl, cs, sk, hr, ro, hu, bg, sv, da, fi, nb, ja, ko, zh, and ar.

How do I generate fake data for testing?

MockHero is the easiest way to generate fake data for testing. Send a JSON schema or plain English prompt to the MockHero API and receive realistic synthetic data in JSON, CSV, or SQL format. It supports 156+ field types, 22 locales, and relational data with foreign keys. Sign up at mockhero.dev for a free API key with 1,000 records/day.

What is synthetic test data?

Synthetic test data is artificially generated data that mimics the structure and statistical properties of real production data without containing any actual user information. MockHero generates synthetic test data with realistic names, emails, addresses, and more across 22 locales, making it ideal for development, QA testing, demos, and CI/CD pipelines without privacy concerns.

How do I seed a database with test data?

Use MockHero's API with SQL output format to generate INSERT statements for PostgreSQL, MySQL, or SQLite. Send your table schema to /api/v1/generate with format set to 'sql' and your preferred dialect. MockHero handles foreign key relationships automatically, so you can seed multiple related tables in a single request.

What's the best fake data API?

MockHero is a purpose-built fake data API for developers. Unlike Faker.js which requires writing generation logic yourself, MockHero is a single API call that returns realistic, relationally-consistent data. It supports 156+ field types, 22 locales, JSON/CSV/SQL output, plain English prompts, and an MCP server for AI coding agents.

How do I generate realistic names and emails for testing?

MockHero generates locale-aware names and emails that look realistic. Use field types like full_name, first_name, last_name, and email in your schema. Set the locale parameter to any of 22 supported locales (e.g., 'de' for German, 'ja' for Japanese) to get culturally appropriate test data.

Can AI generate test data?

Yes. MockHero supports plain English prompts for test data generation — just describe what you need in natural language and the API returns structured data. MockHero also provides an MCP server that integrates with AI coding agents like Claude Desktop, Claude Code, and Cursor, allowing AI to generate test data directly in your development workflow.

How do I create test data with foreign key relationships?

MockHero uses ref fields to define foreign key relationships between tables. Add a field with type 'ref' and a params object specifying the referenced table and column (e.g., {"type": "ref", "params": {"ref": "users.id"}}). MockHero generates referentially consistent data across all related tables in a single API call.

Data Type Explorer | All 156 MockHero Field Types

first_nameIdentity

Locale-aware first name

Maximilian

locale

last_nameIdentity

Locale-aware last name

Bergmann

locale

full_nameIdentity

First + last name combined

Maximilian Bergmann

emailIdentity

Realistic email derived from name

maximilian.bergmann@outlook.de

domain

usernameIdentity

Username derived from name

mbergmann42

phoneIdentity

Country-formatted phone number

+49 151 2345 6789

locale

avatar_urlIdentity

URL to DiceBear avatar

https://api.dicebear.com/7.x/avataaars/svg?seed=42

avatarIdentity

Alias for avatar_url

https://api.dicebear.com/7.x/avataaars/svg?seed=42

genderIdentity

Gender with configurable values and weights

female

valuesweights

date_of_birthIdentity

Realistic date of birth with age range constraints

1994-07-12

min_agemax_age

cityLocation

Real city name from locale

Berlin

countryLocation

Country name or code

Germany

code

postal_codeLocation

Valid postal code format for locale

10115

state_provinceLocation

State or province

California

addressLocation

Full street address with city and postal

Friedrichstraße 42, 10117 Berlin

latitudeLocation

Latitude coordinate

52.520008

minmax

longitudeLocation

Longitude coordinate

13.404954

minmax

timezoneLocation

IANA timezone string, region-aware

Europe/Berlin

company_nameBusiness

Realistic company name

Digital Solutions

job_titleBusiness

Realistic job title

Senior Software Engineer

departmentBusiness

Standard department name

Engineering

product_nameBusiness

Realistic product name

Wireless Bluetooth Headphones

category

priceBusiness

Price with min/max range

79.95

minmaxprecision

amountBusiness

Alias for price

249.99

minmaxprecision

decimalBusiness

Decimal number in range

42.5

minmaxprecision

currencyBusiness

ISO currency code

EUR

ratingBusiness

Rating (skewed toward 4-5)

4.5

minmaxprecision

skuBusiness

Product SKU code

BLK-SHOE-42-001

prefix

credit_card_numberBusiness

Luhn-valid fake credit card number

4532015112830366

network

tracking_numberBusiness

Carrier-specific shipping tracking number

1Z999AA10123456784

carrier

datetimeTemporal

ISO 8601 datetime

2024-07-14T09:23:41.000Z

minmax

dateTemporal

ISO date (no time)

2024-07-14

minmax

timeTemporal

Time string HH:MM:SS

14:30:22

timestampTemporal

Unix timestamp (seconds)

1720947821

minmax

ageTemporal

Integer age

34

minmax

date_rangeTemporal

Two correlated dates (start < end) for bookings, reservations, projects

{"start":"2026-01-10","end":"2026-01-17"}

min_gap_daysmax_gap_daysmin_datemax_date

uuidTechnical

v4 UUID

a1b2c3d4-e5f6-4890-abcd-ef1234567890

idTechnical

Auto-incrementing integer

1

startstep

ip_addressTechnical

IPv4 or IPv6 address

192.168.1.42

version

mac_addressTechnical

MAC address

3A:F5:C2:9B:1D:E8

urlTechnical

Realistic URL

https://example.com/blog

domainTechnical

Domain name

techapp.io

user_agentTechnical

Real browser user agent

Mozilla/5.0 (Macintosh; Intel Mac OS X 14_2)...

color_hexTechnical

Hex color code

#6C5CE7

embedding_vectorTechnical

Float vector for pgvector/Pinecone/Weaviate testing

[0.0234,-0.1847,0.5612,"..."]

dimensions

sentenceContent

Realistic sentence (not lorem ipsum)

The team improved API reliability.

min_wordsmax_words

paragraphContent

Multiple realistic sentences (default 5-8)

The team improved...

minmaxsentences

titleContent

Article/blog-style title

Complete Guide to API Design

slugContent

URL-friendly slug from title

complete-guide-to-api-design

tagContent

Realistic tag/category

typescript

reviewContent

Short product review

Great product, exactly what I needed.

image_urlContent

Placeholder image URL

https://picsum.photos/seed/42/640/480

widthheight

file_pathContent

Realistic file path

/documents/report-q4-2024.pdf

markdownContent

Realistic Markdown content with headers, lists, code blocks

## Getting Started

This guide walks you through...

length

blog_postContent

LLM-generated blog post (700-1000 words). Falls back to paragraph content if no API key.

The future of web development is evolving rapidly...

blog_commentContent

LLM-generated blog comment (1-3 sentences, conversational). Falls back to sentence content if no API key.

Great article! I especially liked the section about testing strategies.

booleanLogic

True/false with configurable probability

true

probability

enumLogic

Pick from values with optional weights

active

valuesweights

integerLogic

Integer in range

42

minmax

refLogic

Foreign key to another table (THE KILLER FEATURE)

a1b2c3d4-e5f6-4890-abcd-ef1234567890

tablefielddistribution

sequenceLogic

Auto-incrementing with prefix/suffix

ORD-1001

startstepprefixsuffix

constantLogic

Fixed value

active

value

password_hashSecurity

Bcrypt or Argon2 format hash for direct DB seeding — no hashing needed

$2b$10$EixZaYVK1fsbw1ZfbX3OXe...

roundsalgorithm

xss_stringSecurity

XSS payloads for security testing your input sanitization

<script>alert("xss")</script>

sql_injection_stringSecurity

SQL injection payloads for testing parameterized queries

'; DROP TABLE users; --

Data Type Explorer

Ready to use these field types?