📇 A simple and sane fake data generator for C#, F#, and VB.NET. Based on and ported from the famed faker.js.
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Bogus for .NET: C#, F#, and VB.NET

Project Description

Hello. I'm your host Brian Chavez (twitter). Bogus is a simple and sane fake data generator for .NET languages like C#, F# and VB.NET. Bogus is fundamentally a C# port of faker.js and inspired by FluentValidation's syntax sugar.

Bogus will help you load databases, UI and apps with fake data for your testing needs. If you like Bogus star ⭐️ the repository and show your friends! 😄 If you find Bogus useful consider supporting the project by purchasing a Bogus Premium license that gives you extra Bogus superpowers! 💫 💪

Download & Install

Nuget Package Bogus

Install-Package Bogus

Minimum Requirements: .NET Standard 1.3 or .NET Framework 4.0.

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The Great C# Example

public enum Gender

//Set the randomzier seed if you wish to generate repeatable data sets.
Randomizer.Seed = new Random(8675309);

var fruit = new[] { "apple", "banana", "orange", "strawberry", "kiwi" };

var orderIds = 0;
var testOrders = new Faker<Order>()
    //Ensure all properties have rules. By default, StrictMode is false
    //Set a global policy by using Faker.DefaultStrictMode
    //OrderId is deterministic
    .RuleFor(o => o.OrderId, f => orderIds++)
    //Pick some fruit from a basket
    .RuleFor(o => o.Item, f => f.PickRandom(fruit))
    //A random quantity from 1 to 10
    .RuleFor(o => o.Quantity, f => f.Random.Number(1, 10));

var userIds = 0;
var testUsers = new Faker<User>()
    //Optional: Call for objects that have complex initialization
    .CustomInstantiator(f => new User(userIds++, f.Random.Replace("###-##-####")))

    //Use an enum outside scope.
    .RuleFor(u => u.Gender, f => f.PickRandom<Gender>())

    //Basic rules using built-in generators
    .RuleFor(u => u.FirstName, (f, u) => f.Name.FirstName(u.Gender))
    .RuleFor(u => u.LastName, (f, u) => f.Name.LastName(u.Gender))
    .RuleFor(u => u.Avatar, f => f.Internet.Avatar())
    .RuleFor(u => u.UserName, (f, u) => f.Internet.UserName(u.FirstName, u.LastName))
    .RuleFor(u => u.Email, (f, u) => f.Internet.Email(u.FirstName, u.LastName))
    .RuleFor(u => u.SomethingUnique, f => $"Value {f.UniqueIndex}")

    //Use a method outside scope.
    .RuleFor(u => u.CartId, f => Guid.NewGuid())
    //Compound property with context, use the first/last name properties
    .RuleFor(u => u.FullName, (f, u) => u.FirstName + " " + u.LastName)
    //And composability of a complex collection.
    .RuleFor(u => u.Orders, f => testOrders.Generate(3).ToList())
    //Optional: After all rules are applied finish with the following action
    .FinishWith((f, u) =>
            Console.WriteLine("User Created! Id={0}", u.Id);

var user = testUsers.Generate();

User Created! Id=0
  "Id": 0,
  "FirstName": "Audrey",
  "LastName": "Spencer",
  "FullName": "Audrey Spencer",
  "UserName": "Audrey_Spencer72",
  "Email": "Audrey82@gmail.com",
  "Avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/itstotallyamy/128.jpg",
  "CartId": "863f9462-5b88-471f-b833-991d68db8c93",
  "SSN": "923-88-4231",
  "Gender": 0,
  "Orders": [
      "OrderId": 0,
      "Item": "orange",
      "Quantity": 8
      "OrderId": 1,
      "Item": "banana",
      "Quantity": 2
      "OrderId": 2,
      "Item": "kiwi",
      "Quantity": 9
} */

Click here for F# and VB.NET examples!


Since we're a port of faker.js, we support a whole bunch of different locales. Here's an example in Korean:

public void With_Korean_Locale()
    var lorem = new Bogus.DataSets.Lorem(locale: "ko");

/* 국가는 무상으로 행위로 의무를 구성하지 신체의 처벌받지 예술가의 경우와 */

Bogus supports the following locales:

Locale Code Language Locale Code Language
ar Arabic id_ID Indonesia
az Azerbaijani it Italian
cz Czech ja Japanese
de German ko Korean
de_AT German (Austria) lv Latvian
de_CH German (Switzerland) nb_NO Norwegian
el Greek nep Nepalese
en English nl Dutch
en_AU Australia (English) nl_BE Dutch (Belgium)
en_au_ocker Australia Ocker (English) pl Polish
en_BORK Bork (English) pt_BR Portuguese (Brazil)
en_CA Canada (English) pt_PT Portuguese (Portugal)
en_GB Great Britain (English) ro Romanian
en_IE Ireland (English) ru Russian
en_IND India (English) sk Slovakian
en_US United States (English) sv Swedish
es Spanish tr Turkish
es_MX Spanish Mexico uk Ukrainian
fa Farsi vi Vietnamese
fr French zh_CN Chinese
fr_CA Canada (French) zh_TW Chinese (Taiwan)
ge Georgian

Note: Some locales may not have a complete data set. For example, zh_CN does not have a lorem data set, but ko has a lorem data set. Bogus will default to en if a locale-specific data set is not found. To further illustrate the previous example, the missing zh_CN:lorem data set will default to the en:lorem data set.

If you'd like to help contribute new locales or update existing ones please see our Creating Locales wiki page for more info.

Without Fluent Syntax

You can use Bogus without a fluent setup. The examples below highlight three alternative ways to use Bogus without a fluent syntax setup.

  1. Using the Faker facade.
  2. Using DataSets directly.
  3. Using Faker<T> inheritance.

All three alternative styles of using Bogus produce the same Order result as demonstrated below:

public void Using_The_Faker_Facade()
    var faker = new Faker("en");
    var o = new Order()
            OrderId = faker.Random.Number(1, 100),
            Item = faker.Lorem.Sentence(),
            Quantity = faker.Random.Number(1, 10)
public void Using_DataSets_Directly()
    var random = new Bogus.Randomizer();
    var lorem = new Bogus.DataSets.Lorem("en");
    var o = new Order()
            OrderId = random.Number(1, 100),
            Item = lorem.Sentence(),
            Quantity = random.Number(1, 10)
public void Using_FakerT_Inheritance()
   public class OrderFaker : Faker<Order> {
      public OrderFaker() {
         RuleFor(o => o.OrderId, f => f.Random.Number(1, 100));
         RuleFor(o => o.Item, f => f.Lorem.Sentence());
         RuleFor(o => o.Quantity, f => f.Random.Number(1, 10));
   var orderFaker = new OrderFaker();
   var o = orderFaker.Generate();
  "OrderId": 61,
  "Item": "vel est ipsa",
  "Quantity": 7
} */

Bogus API Support

  • Address
    • ZipCode - Get a zipcode.
    • City - Get a city name.
    • StreetAddress - Get a street address.
    • CityPrefix - Get a city prefix.
    • CitySuffix - Get a city suffix.
    • StreetName - Get a street name.
    • BuildingNumber - Get a building number.
    • StreetSuffix - Get a street suffix.
    • SecondaryAddress - Get a secondary address like 'Apt. 2' or 'Suite 321'.
    • County - Get a county.
    • Country - Get a country.
    • FullAddress - Get a full address like Street, City, Country.
    • CountryCode - Get a random ISO 3166-1 country code.
    • State - Get a state.
    • StateAbbr - Get a state abbreviation.
    • Latitude - Get a Latitude
    • Longitude - Get a Longitude
    • Direction - Generates a cardinal or ordinal direction. IE: Northwest, South, SW, E.
    • CardinalDirection - Generates a cardinal direction. IE: North, South, E, W.
    • OrdinalDirection - Generates an ordinal direction. IE: Northwest, Southeast, SW, NE.
  • Commerce
    • Department - Get a random commerce department.
    • Price - Get a random product price.
    • Categories - Get random product categories.
    • ProductName - Get a random product name.
    • Color - Get a random color.
    • Product - Get a random product.
    • ProductAdjective - Random product adjective.
    • ProductMaterial - Random product material.
  • Company
    • CompanySuffix - Get a company suffix. "Inc" and "LLC" etc.
    • CompanyName - Get a company name.
    • CatchPhrase - Get a company catch phrase.
    • Bs - Get a company BS phrase.
  • Database
    • Column - Generates a column name.
    • Type - Generates a column type.
    • Collation - Generates a collation.
    • Engine - Generates a storage engine.
  • Date
    • Past - Get a date in the past between refDate and years past that date.
    • Soon - Get a date and time that will happen soon.
    • Future - Get a date in the future between refDate and years forward of that date.
    • Between - Get a random date between start and end.
    • Recent - Get a random date/time within the last few days since now.
    • Timespan - Get a random span of time.
    • Month - Get a random month
    • Weekday - Get a random weekday
  • Finance
    • Account - Get an account number. Default length is 8 digits.
    • AccountName - Get an account name. Like "savings", "checking", "Home Loan" etc..
    • Amount - Get a random amount. Default 0 - 1000.
    • TransactionType - Get a transaction type: "deposit", "withdrawal", "payment", or "invoice".
    • Currency - Get a random currency.
    • CreditCardNumber - Generate a random credit card number with valid Luhn checksum.
    • CreditCardCvv - Generate a credit card CVV
    • BitcoinAddress - Generates a random Bitcoin address.
    • EthereumAddress - Generate a random Ethereum address.
    • RoutingNumber - Generates an ABA routing number with valid check digit.
    • Bic - Generates Bank Identifier Code (BIC) code.
    • Iban - Generates an International Bank Account Number (IBAN).
  • Hacker
    • Abbreviation - Returns an abbreviation.
    • Adjective - Returns a adjective.
    • Noun - Returns a noun.
    • Verb - Returns a verb.
    • IngVerb - Returns an -ing verb.
    • Phrase - Returns a phrase.
  • Images
    • Image - Gets a random image.
    • Abstract - Gets an abstract looking image.
    • Animals - Gets an image of an animal.
    • Business - Gets a business looking image.
    • Cats - Gets a picture of a cat.
    • City - Gets a city looking image.
    • Food - Gets an image of food.
    • Nightlife - Gets an image with city looking nightlife.
    • Fashion - Gets an image in the fashion category.
    • People - Gets an image of humans.
    • Nature - Gets an image of nature.
    • Sports - Gets an image related to sports.
    • Technics - Get a technology related image.
    • Transport - Get a transportation related image.
    • DataUri - Get a SVG data URI image with a specific width and height.
  • Internet
    • Avatar - Generates a legit Internet URL avatar from twitter accounts.
    • Email - Generates an email address.
    • ExampleEmail - Generates an example email with @example.com.
    • UserName - Generates user names.
    • DomainName - Generates a random domain name.
    • DomainWord - Generates a domain word used for domain names.
    • DomainSuffix - Generates a domain name suffix like .com, .net, .org
    • Ip - Gets a random IP address.
    • Ipv6 - Generates a random IPv6 address.
    • UserAgent - Generates a random user agent.
    • Mac - Gets a random mac address.
    • Password - Generates a random password.
    • Color - Gets a random aesthetically pleasing color near the base RGB. See here.
    • Protocol - Returns a random protocol. HTTP or HTTPS.
    • Url - Generates a random URL.
    • UrlWithPath - Get a random URL with random path.
  • Lorem
    • Word - Get a random lorem word.
    • Words - Get some lorem words
    • Letter - Get a character letter.
    • Sentence - Get a random sentence of specific number of words.
    • Sentences - Get some sentences.
    • Paragraph - Get a paragraph.
    • Paragraphs - Get a specified number of paragraphs.
    • Text - Get random text on a random lorem methods.
    • Lines - Get lines of lorem.
    • Slug - Slugify lorem words.
  • Name
    • FirstName - Get a first name. Getting a gender specific name is only supported on locales that support it.
    • LastName - Get a last name. Getting a gender specific name is only supported on locales that support it.
    • FullName - Get a full name, concatenation of calling FirstName and LastName.
    • Prefix - Gets a random prefix for a name.
    • Suffix - Gets a random suffix for a name.
    • FindName - Gets a full name.
    • JobTitle - Gets a random job title.
    • JobDescriptor - Get a job description.
    • JobArea - Get a job area expertise.
    • JobType - Get a type of job.
  • PhoneNumbers
    • PhoneNumber - Get a phone number.
    • PhoneNumberFormat - Gets a phone number via format array index as defined in a locale's phone_number.formats[] array.
  • Rant
    • Review - Generates a random user review.
    • Reviews - Generate an array of random reviews.
  • System
    • FileName - Get a random file name.
    • DirectoryPath - Get a random directory path (Unix).
    • FilePath - Get a random file path (Unix).
    • MimeType - Get a random mime type
    • CommonFileType - Returns a commonly used file type.
    • CommonFileExt - Returns a commonly used file extension.
    • FileType - Returns any file type available as mime-type.
    • FileExt - Gets a random extension for the given mime type.
    • Semver - Get a random semver version string.
    • Version - Get a random System.Version.
    • Exception - Get a random Exception with a fake stack trace.
    • AndroidId - Get a random GCM registration ID.
    • ApplePushToken - Get a random Apple Push Token
    • BlackBerryPin - Get a random BlackBerry Device PIN

API Extension Methods

  • using Bogus.Extensions.Brazil;
    • Bogus.Person.Cpf() - Cadastro de Pessoas Físicas
    • Bogus.DataSets.Company.Cnpj() - Cadastro Nacional da Pessoa Jurídica
  • using Bogus.Extensions.Canada;
    • Bogus.Person.Sin() - Social Insurance Number for Canada
  • using Bogus.Extensions.Denmark;
    • Bogus.Person.Cpr() - Danish Personal Identification number
  • using Bogus.Extensions.Finland;
    • Bogus.Person.Henkilötunnus() - Finnish Henkilötunnus
  • using Bogus.Extensions.Italy;
    • Bogus.Person.CodiceFiscale() - Codice Fiscale
    • Bogus.DataSets.Finance.CodiceFiscale() - Codice Fiscale
  • using Bogus.Extensions.Portugal;
    • Bogus.Person.Nif() - Número de Identificação Fiscal (NIF)
    • Bogus.DataSets.Company.Nipc() - Número de Identificação de Pessoa Colectiva (NIPC)
  • using Bogus.Extensions.UnitedKingdom;
    • Bogus.DataSets.Finance.SortCode() - Banking Sort Code
    • Bogus.DataSets.Finance.Nino() - National Insurance Number
  • using Bogus.Extensions.UnitedStates;
    • Bogus.Person.Ssn() - Social Security Number
    • Bogus.DataSets.Company.Ein() - Employer Identification Number
  • using Bogus.Distributions.Gaussian;
    • Randomizer.GaussianInt() - Generate an int based on a specific normal distribution.
    • Randomizer.GaussianFloat() - Generate a float based on a specific normal distribution.
    • Randomizer.GaussianDouble() - Generate a double based on a specific normal distribution.
    • Randomizer.GaussianDecimal() - Generate a decimal based on a specific normal distribution.

Amazing Community Extensions

  • AutoBogus (NuGet Package) by @nickdodd79 - Extends Bogus by adding automatic .RuleFor() creation and population capabilities.
  • NaughtyStrings.Bogus (NuGet Package) by @SimonCropp - Extends Bogus with list of naughty strings which have a high probability of causing issues when used as user-input data. Examples:
    • .SQLInjection() - Strings which can cause a SQL injection if inputs are not sanitized.
    • .ScriptInjection() - Strings which attempt to invoke a benign script injection; shows vulnerability to XSS.
    • .iOSVulnerabilities() - Strings which crashed iMessage in various versions of iOS.
    • .KnownCVEsandVulnerabilities() - Strings that test for known vulnerabilities.
    • .ServerCodeInjection() - Strings which can cause user to run code on server as a privileged user.
    • and more!
  • WaffleGenerator.Bogus (NuGet Package) by @SimonCropp - The Waffle Generator produces of text which, on first glance, looks like real, ponderous, prose; replete with clichés.
  • NodaTime.Bogus (NuGet Package) by @SimonCropp - Adds support for NodaTime to Bogus.
  • CountryData.Bogus (NuGet Package) by @SimonCropp - Wrapper around GeoNames Data. Examples:
    • .Country().Name() - Random country name.
    • .Country().CurrencyCode() - Random currency code.
    • .Australia().Capital() - Country capital.
    • .Country().Iceland().PostCode() - Random country post code.

Bogus Premium Extensions!

Bogus Premium [Purchase Now!] by @bchavez
You can help support the Bogus open source project by purchasing a Bogus Premium license! With an active premium license you'll be supporting this cool open-source project. You'll also gain new superpowers that extended Bogus with new features and exclusive data sets! Check 'em out below!

  • Premium: Bogus.Tools.Analyzer (NuGet Package) - Save time using this handy Roslyn analyzer to generate and detect missing .RuleFor() rules at development & compile time! This tool is included with the Bogus Premium license!
  • Premium: Bogus.Locations (NuGet Package) - A dataset that contains real geographical information for places and things. Create fake GPS points and paths. Helpful for creating geodesic data for location-based aware apps.
    • Location
      • Altitude - Generate a random altitude, in meters. Default max height is 8848m (Mount Everest). Heights are always positive.
      • AreaCircle - Get a latitude and longitude within a specific radius in meters.
      • Depth - Generate a random depth, in meters. Default max depth is -10994m (Mariana Trench). Depths are always negative.
      • Geohash - Generates a random Geohash. See.
  • Premium: Bogus.Healthcare (NuGet Package) - A data set for the Healthcare industry. Generate fake medical records, injuries, diagnosis, drugs, dosages, human anatomy, and ICD-9 medical codes. Especially helpful in HIPAA regulated environments!
    • Drugs
      • Administration - Get how a drug should be administered. IE: oral, nasal, injection.
      • Dosage - Get a drug dosage with MG units
      • DosageAmount - Get a drug dosage.
      • DosageForm - Get the form of a drug. IE: tablet, capsule, gel.
      • Ingredient - Get a drug ingredient. IE: folic acid, magnesium hydroxide, ibuprofen.
      • Vitamin - Get a random vitamin.
    • Human
      • BloodType - Get a random blood type. Ex: A+, OB
      • BodyPartExternal - Get an external body part name. IE: Head, Arm, Leg.
      • BodyPartInternal - Get an internal body part name. IE: Bladder, Lung, Heart.
      • BodyRegion - Get a human body region. IE: Head and Neck, Thorax.
      • BodySystem - Get a human body system. IE: Digestive, Nervous, Circulatory.
      • Diagnosis - Shortcut to Icd9.DiagnosisLongDescription".
      • InfectiousDisease - Get an infectious disease. IE: Chickenpox, Polio, Zika Fever.
      • Pain - Get a human pain. Ex: Chest pain, Headache, Toothache.
      • Plasma - Get a random plasma type. Ex: O, A, B, AB
      • Procedure - Shortcut to Icd9.ProcedureLongDescription.
    • Icd9
      • DiagnosisCode - Get a ICD9 diagnosis code.
      • DiagnosisEntry - Get a medical diagnosis.
      • DiagnosisLongDescription - Get a medical diagnosis description. IE: Meningitis due to coxsackie virus.
      • DiagnosisShortDescription - Get a short description of a medical diagnosis.
      • ProcedureCode - Get a ICD9 procedure code.
      • ProcedureEntry - Get a medical procedure.
      • ProcedureLongDescription - Get a medical procedure description.
      • ProcedureShortDescription - Get a short description of a medical procedure.
    • Medical
      • Hospital - Get a random hospital.
      • HospitalCity - Get a hospital city.
      • HospitalName - Get a random hospital name. IE: UCLA Medical Center
      • HospitalState - Get a hospital state.
      • HospitalStreetAddress - Get a hospital street address.
      • HospitalZipCode - Get a hospital ZipCode.
      • Phrase - Get a random medical phrase.
      • Word - Get a medical word.
  • Premium: Bogus.Hollywood (NuGet Package)- A dataset for the Entertainment industry.
    • Movies
      • ActorName - Get a famous actor. IE: Keanu Reeves, Liam Neeson, and Natalie Portman.
      • MovieCollection - Get a random movie collection. IE: Star Wars Collection, Indiana Jones Collection.
      • MovieOverview - Get a random movie overview
      • MovieReleaseDate - Get a random movie release date.
      • MovieTagline - Get a random movie tagline.
      • MovieTitle - Get a random movie title
      • Production - Get a production company.
    • Tv
      • ActorName - Get a famous actor. IE: Keanu Reeves, Liam Neeson, and Natalie Portman.
      • Network - Get a random TV network. IE: BBC, ABC, NBC, FOX.
      • Production - Get a production company
      • Series - Get a name of a TV series. IE: Rick and Morty, Silicon Valley, The Walking Dead
  • Premium: Bogus.Text (NuGet Package) - A dataset that contains historical texts in the public domain. Create fake sentences from famous speeches, classic books, and law
    • Literature
      • CommonSense - Text from "Common Sense, by Thomas Paine (1776)"
      • JfkSpeech - Text from "JFK's Inaugural Address"
      • Knowledge - Text from "A Treatise Concerning the Principles of Human knowledge, by George Berkeley (1710)"

Helper Methods

The features shown below come standard with the Bogus NuGet package.


If you want to generate a Person with context relevant properties like an email that looks like it belongs to someone with the same first/last name, create a person!

public void Create_Context_Related_Person()
    var person = new Bogus.Person();


  "FirstName": "Lee",
  "LastName": "Brown",
  "UserName": "Lee_Brown3",
  "Avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/ccinojasso1/128.jpg",
  "Email": "Lee_Brown369@yahoo.com",
  "DateOfBirth": "1984-01-16T21:31:27.87666",
  "Address": {
    "Street": "2552 Bernard Rapid",
    "Suite": "Suite 199",
    "City": "New Haskell side",
    "ZipCode": "78425-0411",
    "Geo": {
      "Lat": -35.8154,
      "Lng": -140.2044
  "Phone": "1-500-790-8836 x5069",
  "Website": "javier.biz",
  "Company": {
    "Name": "Kuphal and Sons",
    "CatchPhrase": "Organic even-keeled monitoring",
    "Bs": "open-source brand e-business"
} */


Replace a formatted string with random numbers #, letters ?, or * random number or letter:

public void Create_an_SSN()
    var ssn = new Bogus.Randomizer().Replace("###-##-####");

    var code = new Randomizer().Replace("##? ??? ####");

    var serial = new Randomizer().Replace("**-****");
"39E SPC 0790"

Parse Handlebars

You can also parse strings in the following format:

public void Handlebar()
    var faker = new Faker();
    var randomName = faker.Parse("{{name.lastName}}, {{name.firstName}} {{name.suffix}}");

"Roob, Michale PhD"

The name of a dataset is determined using DataCategory attribute or class name otherwise. (i.e PhoneNumber dataset in handlebars expression should be named as phone_number)

You can pass parameters to methods using braces:

public void HandlebarWithParameters()
    var faker = new Faker();
    var randomName = faker.Parse("{{name.firstname(Female)}}, {{name.firstname(Male)}}");

"Lindsay, Jonathan"

Implicit and Explicit Type Conversion

You can also use implicit type conversion to make your code look cleaner without having to explicitly call Faker<T>.Generate().

var orderFaker = new Faker<Order>()
                     .RuleFor(o => o.OrderId, f => f.IndexVariable++)
                     .RuleFor(o => o.Item, f => f.Commerce.Product())
                     .RuleFor(o => o.Quantity, f => f.Random.Number(1,3));

Order testOrder1 = orderFaker;
Order testOrder2 = orderFaker;

  "OrderId": 0,
  "Item": "Computer",
  "Quantity": 2
  "OrderId": 1,
  "Item": "Tuna",
  "Quantity": 3

//Explicit works too!
var anotherOrder = (Order)orderFaker;

Bulk Rules

Sometimes writing .RuleFor(x => x.Prop, ...) can get repetitive, use the .Rules((f, t) => {...}) shortcut to specify rules in bulk as shown below:

public void create_rules_for_an_object_the_easy_way()
    var faker = new Faker<Order>()
        .Rules((f, o) =>
                o.Quantity = f.Random.Number(1, 4);
                o.Item = f.Commerce.Product();
                o.OrderId = 25;
    Order o = faker.Generate();

Note: When using the bulk .Rules(...) action, StrictMode cannot be set to true since individual properties of type T cannot be indpendently checked to ensure each property has a rule.

F# and VB.NET Examples

The Fabulous F# Examples

  • Using the Faker facade with immutable F# record types:
type Customer = { FirstName : string
                  LastName : string
                  Age : int
                  Title : string }

//The faker facade
let f = Faker();

let generator() = 
   { FirstName = f.Name.FirstName()
     LastName  = f.Name.LastName()
     Age       = f.Random.Number(18,60)
     Title     = f.Name.JobTitle() }
generator() |> Dump |> ignore

  FirstName = "Russell"
  LastName = "Nader"
  Age = 34
  Title = "Senior Web Officer"
  • Using the Faker<T> class with immutable F# record types:
type Customer = { FirstName : string
                  LastName : string
                  Age : int
                  Title : string }

let customerFaker =
        .CustomInstantiator(fun f ->
             { FirstName = f.Name.FirstName()
               LastName  = f.Name.LastName()
               Age       = f.Random.Number(18,60)
               Title     = f.Name.JobTitle() })

customerFaker.Generate() |> Dump |> ignore

  FirstName = "Sasha"
  LastName = "Roberts"
  Age = 20;
  Title = "Internal Security Specialist"
  • Using the Faker<T> class with mutable classes in F#:
open Bogus
type Customer() =
  member val FirstName = "" with get, set
  member val LastName = "" with get, set
  member val Age = 0 with get,set
  member val Title = "" with get,set

let faker = 
          //Make a rule for each property
          .RuleFor( (fun c -> c.FirstName), fun (f:Faker) -> f.Name.FirstName() )
          .RuleFor( (fun c -> c.LastName), fun (f:Faker) -> f.Name.LastName() )

          //Or, alternatively, in bulk with .Rules()
          .Rules( fun f c -> 
                    c.Age <- f.Random.Int(18,35) 
                    c.Title <- f.Name.JobTitle() )
faker.Generate() |> Dump |> ignore

  FirstName: Jarrell
  LastName: Tremblay
  Age: 32
  Title: Senior Web Designer

The Very Basic VB.NET Example

Imports Bogus

Public Class Customer
    Public Property FirstName() As String
    Public Property LastName() As String
    Public Property Age() As Integer
    Public Property Title() As String
End Class

Sub Main
    Dim faker As New Faker(Of Customer)
    '-- Make a rule for each property
    faker.RuleFor( Function(c) c.FirstName, Function(f) f.Name.FirstName) _
         .RuleFor( Function(c) c.LastName, Function(f) f.Name.LastName) _
         .Rules( Sub(f, c)   '-- Or, alternatively, in bulk with .Rules() 
                   c.Age = f.Random.Int(18,35) 
                   c.Title = f.Name.JobTitle()
                 End Sub )
End Sub

' FirstName: Jeremie 
' LastName: Mills 
' Age: 32 
' Title: Quality Supervisor 


  • Download the source code.
  • Run build.cmd.

Upon successful build, the results will be in the \__compile directory. The build.cmd compiles the C# code and embeds the locales in Source\Bogus\data. If you want to rebuild the NuGet packages run build.cmd pack and the NuGet packages will be in __package.

Rebundling Locales

If you wish to re-bundle the latest faker.js locales, you'll need to first:

  1. git submodule init
  2. git submodule update
  3. Ensure, NodeJS and gulp are properly installed.
  4. cd Source\Builder
  5. npm install to install required dev dependencies.
  6. gulp import.locales to regenerate locales in Source\Bogus\data.
  7. In solution explorer add any new locales not already included as an EmbeddedResource.
  8. Finally, run build.cmd.



Created by Brian Chavez.

faker.js made possible by Matthew Bergman & Marak Squires.

A big thanks to GitHub and all contributors: