Field type reference

Every generator available in the schema builder, grouped by category. Options marked in mono can be tuned per field, and every field additionally accepts a Blank % to inject nulls and a Unique toggle that retries until every value in the column differs — if a type cannot produce enough distinct values, the builder warns you and the remaining duplicates are kept.

Not sure which fields belong together? Start from a test-data workflow for databases, mock APIs, QA automation or spreadsheets. Safety characteristics and documentation-only ranges are explained in the data methodology.

Basics

TypeDescription & optionsExample
Row NumberSequential counter. Options: start.1, 2, 3…
IntegerUniform random whole number. Options: min, max.42
DecimalRandom decimal. Options: min, max, decimals.483.07
Booleantrue or false. Options: true % — the probability of true (default 50).true
UUID v4RFC 4122 version-4 identifier.b3c9a1f2-6d4e-4a7b-9c1d-2f8e5a6b7c8d
FormulaMockaroo-compatible formula evaluated per row. Formula can be its own field type, or the f(x) button can transform any generated field using this. Fields are evaluated top-to-bottom.if quantity > 5 then (unit_price * quantity).round(2) else unit_price end
Number (Normal Dist.)Gaussian (bell-curve) number via Box-Muller — more realistic than uniform for ages, prices, latencies. Options: mean, std dev, optional min/max clamp, decimals.97.4

Formula quick reference

Reference earlier fields directly, or use field("Field Name") for names containing spaces. Prefix helper field names with __ to keep them available to formulas while omitting them from every export.

Logic: if / elsif / else / end, postfix if and unless, case / when, and / or, comparisons and ternary expressions.

Functions: random, generate, concat, upper, lower, format, pad, base64, hex, uuid_v5, normal_dist, date, date_diff, day, month, year, time, epoch, now, date offsets from years through seconds, code (returns its argument as a string), and naughty(value, percent) — swaps in a hostile test string (script tag, SQL fragment, control characters) at the given percentage, for input-hardening tests.

Values and methods: arrays, hashes, indexing, nil?, empty?, string case/search/replace methods, numeric rounding and predicates, plus common array methods such as compact, uniq, sort, sum and join.

Person

TypeDescription & optionsExample
First NameGiven names. Options: locale (any, en, es, de, it, tr, jp, in, ar). First Name, Last Name, Full Name and Email Address stay coherent within a row — the email matches the row's name.Elena
Last NameFamily names, coherent with the row's other name fields. Options: locale.Yılmaz
Full NameFirst + last name from one person, matching the row's First/Last Name columns. Options: locale.Marco Rossi
GenderInclusive set of gender labels.Non-binary
Usernameadjective_noun + number.swift_falcon42
PasswordRandom unambiguous characters. Options: length.kR7!mQ2vX9pZ
Email AddressBuilt from the row's First/Last Name (transliterated to ASCII) on safe example domains.elena.rossi7@example.org
Phone NumberPattern-driven. Options: format (# = digit).+1 (555) 014-2831
Job TitleCommon roles across tech and business.QA Engineer
DepartmentTypical org departments.Quality Assurance
Avatar URLPlaceholder avatar image URL.https://i.pravatar.cc/150?u=48293017
AgeWhole-number age. Options: min, max.34
BirthdateDate of birth derived from an age range. Options: min age, max age, format.1991-04-17

Location

TypeDescription & optionsExample
Country50 country names. Country, Country Code, City and Full Address stay coherent within a row — a row never pairs a city with the wrong country. A second field of the same kind draws independently.Netherlands
Country Code (ISO)ISO 3166-1 alpha-2 code, matching the row's Country.NL
City~110 world cities, drawn from the row's country.Izmir
State (US)US state name.Oregon
State Abbrev (US)Two-letter US state code.OR
Street AddressNumber + street + suffix.2847 Maple Avenue
Zip / Postal CodePattern-driven. Options: format.94103
Full AddressStreet, city, zip and country in one line; the city and country match the row's other location fields.193 Cedar Lane, Vienna 20481, Austria
Latitude−90 to 90, six decimals.48.208176
Longitude−180 to 180, six decimals.16.373819

Internet

TypeDescription & optionsExample
Domain NameCompany-style domain on a reserved documentation TLD.novadynamics.test
URLhttps URL with two path segments on a reserved documentation TLD.https://emberlabs.test/lorem/ipsum
IPv4 AddressRFC 5737 documentation-only address from 192.0.2.0/24, 198.51.100.0/24 or 203.0.113.0/24.192.0.2.42
IPv6 AddressRFC 3849 documentation-only address from 2001:db8::/32.2001:db8:85a3:0000:0000:8a2e:0370:7334
MAC AddressColon-separated uppercase hex.0A:1B:2C:3D:4E:5F
Hex Color#RRGGBB.#e8590c
Color NameHuman-readable color word.turquoise
User AgentRealistic modern browser UA strings.Mozilla/5.0 (Windows NT 10.0…) Chrome/126.0
Semvermajor.minor.patch version string.2.14.7
MIME TypeCommon IANA media type.application/json
Hash (hex)Deterministic-looking hex digest — not a real cryptographic hash. Options: length (8–64), optional source field to derive it from another field above it (same source + seed ⇒ same hash).9f2c7a1e4b8d0f36

Business

TypeDescription & optionsExample
Company NamePrefix + suffix, sometimes a legal form.Zenith Analytics GmbH
Product NameAdjective + material + noun.Ergonomic Bamboo Keyboard
PriceTwo-decimal amount. Options: min, max.129.99
Currency CodeISO 4217 code.EUR
IBAN (fake)Country-length-shaped but not checksum-valid or bank-valid. Options: country.DE89 3704 0044 0532 0130 00
Credit Card # (test)Official payment-gateway test PANs only; never use for real payments.4111111111111111
Credit Card TypeMajor card network name.Mastercard
Crypto CoinPopular ticker symbols.ETH
EAN-13 Barcode12 random digits plus a correct EAN-13/ISBN-style check digit.4006381333931
ISBN-13978-prefixed 13-digit code with a correct check digit.9781234567897

Date & Time

TypeDescription & optionsExample
DateDate in a range. Options: from, to, format, order (random, or sequential — evenly spaced across the range in row order, for time-series fixtures).2024-11-03
Time24h clock. Options: seconds.14:07:52
Datetime (ISO 8601)UTC timestamp in a range. Options: from, to, order.2025-03-18T09:41:26Z
Unix TimestampSeconds since epoch. Options: from, to, order.1742291286
Day of WeekMonday–Sunday.Thursday
MonthJanuary–December.March
TimezoneIANA timezone name.Europe/Berlin

Text

TypeDescription & optionsExample
WordSingle lorem word.voluptate
WordsSpace-separated words. Options: count.magna aliqua enim
Sentence6–14 word capitalized sentence.Dolore magna aliqua enim minim veniam quis.
ParagraphMultiple sentences. Options: sentences.Lorem ipsum dolor amet. Sed tempor…
Custom ListYour own values. Options: values (plain a, b, c or weighted a:5, b:1), mode (random, sequential, or weighted — weighted honors the value:weight ratios).pending
My DatasetDraws from a reusable value list saved under My datasets on the builder (one value per line, up to 10,000 values). Datasets are reusable across schemas, and signing in syncs them across devices. Options: dataset (which list), mode (random or sequential).acme-widget
Pattern# digit, ? A–Z, ~ a–z; other chars kept.SKU-4821-QF
Regex PatternGenerates strings matching a constrained regex subset: literals, \d \w \s (+ negations), ., [classes], (groups), alternation |, quantifiers * + ? {n} {n,} {n,m}. No backreferences or lookaround. Options: pattern.ABC-4821
Slugword-word-number, kebab-case.amber-falcon-482
EmojiSingle common emoji.🚀

Missing a type you need? Grab a Pattern / Custom List field, which together cover most bespoke formats.

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