Open-Source Testing · elixirs

faker

Faker is a lightweight Elixir library for generating fake data (names, addresses, emails, etc.) used primarily in testing and database seeding. It requires minimal configuration and integrates directly into Elixir/Phoenix projects for test data generation.

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Source: GitHub — github.com/elixirs/faker

1.2k

GitHub stars

262

Forks

Elixir

Primary language

MIT

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	elixirs/faker
Owner	elixirs
Primary language	Elixir
License	MIT — OSI-approved
Stars	1.2k
Forks	262
Open issues	54
Latest release	v0.19.0 (2026-06-28)
Last updated	2026-07-06
Source	https://github.com/elixirs/faker

What faker is

Pure Elixir library providing deterministic fake data generation across multiple domains (person, address, internet, etc.). Requires OTP 19+ and Elixir 1.6+, with application-level initialization via Faker.start() to access locale data.

Quickstart

Get the faker source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/elixirs/faker.git2cd faker3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Test Data Generation in Elixir/Phoenix Projects

Generate realistic dummy data for unit and integration tests without external services. Simplifies test setup by providing consistent, reproducible fake values for fixtures.

Database Seeding for Development

Populate local development databases with plausible dummy records rapidly. Reduces manual test data creation and enables developers to test with larger datasets locally.

QA/Staging Environment Setup

Seed QA and staging environments with varied, realistic fake data to support comprehensive testing scenarios without exposing production data.

Implementation considerations

Must call Faker.start() in test_helper.exs to initialize locale data; omitting this causes FunctionClauseError when accessing data generators.
Requires explicit dependency declaration (only: :test) in mix.exs to avoid bundling testing library into production releases.
OTP 19+ and Elixir 1.6+ are hard requirements; verify compatibility with your Elixir version before adoption.
Data output is random by default; consider seeding for reproducible test results if needed across test runs.
Library is pure Elixir with no external API calls, reducing operational complexity and network dependencies.

When to avoid it — and what to weigh

Non-Elixir Applications — Requires Elixir runtime. Not suitable for Ruby, Python, Node.js, or other language ecosystems without a separate port or wrapper service.
Production Data Serving — Designed for development and testing only. Not intended to generate data for production user-facing systems or sensitive real-world scenarios.
Complex Multi-Locale Customization — While multi-locale support exists, extensive customization of locale data or highly specialized fake data generation patterns may require additional development effort.
Deterministic Cryptographic Security Requirements — Faker generates data for testing purposes; do not rely on it for security-sensitive token generation, encryption keys, or cryptographic operations.

License & commercial use

Released under MIT License, a permissive open-source license allowing use, modification, and distribution in both open-source and proprietary projects with minimal restrictions.

MIT License permits commercial use without restriction. No license fee, royalty, or attribution requirement for proprietary applications. Ensure compliance with MIT's simple attribution clause if redistributing the source code itself.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Low
DEV.co fit	Good
Assessment confidence	High

Security considerations

Faker is designed for test data generation only and should never be used for security-sensitive operations (token generation, secrets, passwords). No inherent vulnerabilities claimed or stated in data; as a lightweight pure library with minimal dependencies, attack surface is limited. Always keep OTP/Elixir runtime patched.

Alternatives to consider

Factory Bot (Ruby) / Factory Girl

Dominant factory library for Ruby/Rails; if migrating from or standardizing across Ruby and Elixir teams, consider multi-language support strategy.

Forgery (Python) / Faker (Python)

Python ecosystem equivalent if cross-language test data generation is required; separate library per language increases maintenance burden.

Blacksmith (Elixir)

Complementary Elixir library for template-based object building; provides higher-level factory patterns on top of Faker's basic generators.

Software development agency

Build on faker with DEV.co software developers

Faker integrates seamlessly into ExUnit and Phoenix projects. Our team can help evaluate and deploy fake data generation for your QA and staging pipelines.

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faker FAQ

Can I use Faker in production?

Not recommended. Faker is designed for development and testing. Production systems should use real data or dedicated data management services.

Does Faker support localization?

Yes, multi-locale support exists (initialized via Faker.start()). Specific locale options and coverage are not detailed in the provided data; see HexDocs.

Are generated values reproducible across test runs?

Faker generates random data by default. To reproduce values, seed your test framework's random number generator before calling Faker functions.

What are the performance implications?

Unknown from provided data. As a pure in-memory library, performance is likely minimal, but scale behavior with large test datasets requires benchmarking in your environment.

Software development & web development with DEV.co

Need help beyond evaluating faker? DEV.co is a software development agency offering software development services and web development for teams of every size. Our software developers and web developers build custom software, web applications, APIs, and open-source testing integrations — and maintain them long-term.

Need test data strategy for your Elixir application?

Faker integrates seamlessly into ExUnit and Phoenix projects. Our team can help evaluate and deploy fake data generation for your QA and staging pipelines.

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