Random Data from Regex: Generate Matching Test Strings
Random Data from Regex generates strings that match a regular expression using a built-in engine, with no external dependency. It supports character classes, groups, alternation, and bounded quantifiers. Unbounded quantifiers (*) and (+) are limited by a configurable maximum. Lookarounds and backreferences are not supported, so check your pattern against the supported syntax before generating values.
Random Data from Regex is a browser-based tool for generating random strings that match a regular expression. It uses a built-in engine, so it does not rely on an external dependency. Developers can use it to create candidate values for tests, fixtures, seed data, or other workflows that need strings matching a pattern.
The engine supports character classes, groups, alternation, and bounded quantifiers. Unbounded quantifiers, including * and +, are capped at a configurable maximum so their generated repetitions have an upper bound. Lookarounds and backreferences are not supported, so patterns that depend on those features cannot be used as written. Review your expression and the available options before generating a batch.
Regular expressions describe patterns for matching text, while the generated output consists of strings that match the supplied pattern. Converting a pattern into sample strings can save time when you need varied candidate inputs instead of writing them manually. The generated values are useful for exercising code that expects input matching that expression, but they do not replace testing other behavior or cases your pattern does not describe.
The tool runs entirely in your browser, and your input is not sent to a server. It works offline once the page has loaded, so you can generate values without an active connection. The built-in engine and browser-based workflow make Random Data from Regex useful for developers and DevOps engineers creating test data, checking patterns, or preparing examples.
Step 1: Enter the regular expression you want to match. Use supported syntax such as character classes, groups, alternation, and bounded quantifiers.
Step 2: Set the available options, including the configurable maximum for unbounded quantifiers. This cap applies to * and +.
Step 3: Generate random strings from your pattern. The output values are intended to match the regular expression.
Step 4: Review the generated values and copy the ones you need for tests, fixtures, or seed data.
Use case: Create random regex values for test fixtures or seed data. Matching strings can help you exercise code that expects a particular input shape.
Use case: Generate a batch of candidate values at once instead of inventing each example by hand.
Use case: Use randomly generated matches rather than keyboard-typed guesses when you need varied test inputs.
Use case: Prepare sample inputs for testing validation logic that relies on a regular expression.
Use case: Generate matching values to use while checking how an application handles different inputs in a supported pattern.
Use case: Create repeatable-looking sets of example strings for development or debugging without adding an external dependency.