Generate Text from RegExp
Create random strings that match a specific Regular Expression pattern.
Pattern Configuration
Reverse Regex
Most tools test if string matches a regex. This tool does the opposite: it creates strings that match your regex. Perfect for generating test data like fake emails, phone numbers, or passwords.
Create Data with Regex
The Generate Text from RegExp tool flips the script on regular expressions. Instead of using patterns to find text, you use them to create text. This is incredibly powerful for generating mock data for databases, stress testing input forms, or creating unique identifiers.
How to Use
- Choose a preset or enter your custom regex pattern
- Adjust quantity - Generate 1 to 100 strings at once
- View results - See generated strings instantly
- Check statistics - Review count, avg/min/max length
- Download or copy - Export as TXT, CSV, or JSON
Common Use Cases
Mock Database Data
Generate thousands of fake user IDs, SKUs, or transaction codes. Perfect for populating development databases or demos.
Software Testing
Create edge-case test data matching your validation patterns. Test form validators with hundreds of valid inputs instantly.
Unique Identifiers
Generate license keys, API tokens, or session IDs. Ensures all generated strings match your specific format requirements.
Common Uses
Mock Data
Need 50 fake phone numbers? Just use \(\d3\) \d3-\d4.
Test Cases
Generate edge-case strings to ensure your own validators are working correctly.
How it works
- Analyze: We parse your regex structure.
- Traverse: We walk through each token (e.g., `\d`, `[a-z]`).
- Pick: We randomly select a valid character for each token to build the string.
Example Patterns
Frequently Asked Questions
How random is the generated text?
The tool selects random characters that fulfill the criteria of each part of your regex. For specific ranges like [A-Z], any uppercase letter has an equal chance. The randomization uses JavaScript's Math.random() for character selection within valid ranges.
Is there a length limit for generated strings?
Yes, to prevent browser freezing, we cap repetitive quantifiers like '*' or '+' to a safe maximum (usually 10 repetitions). You can control the number of strings generated (1-100), and each pattern is validated before generation.
Can I save the generated strings?
Absolutely! You can download your generated strings in three formats: TXT (newline-separated), CSV (indexed with length), or JSON (complete data with pattern and statistics). Just click the format button you need.
What regex patterns can I use?
The tool supports standard JavaScript regex syntax including character classes ([a-z]), quantifiers ({min,max}, *, +), digits (\d), word characters (\w), and custom ranges. Complex patterns with groups and alternation also work.
How do I generate fake email addresses?
Use the preset 'Email Address' from the dropdown, or create your own pattern like [a-z]{5,10}@[a-z]{5,8}.com. This generates random emails with lowercase usernames and domains. Adjust the numbers to control username length.
Can I use this for password generation?
Yes! Use the 'Strong Password' preset or create patterns like [A-Z][a-z]{5,10}[0-9]{2,4}[!@#$]. This ensures uppercase start, lowercase middle, numbers, and special chars. Generate 100 at once for password lists.
Does it support all regex syntax?
It supports most common regex features: character classes, ranges, quantifiers, and escapes. Complex features like lookahead/lookbehind may not work in generation mode since they're matching-only constructs. Stick to generative patterns.
How many strings can I generate at once?
You can generate 1 to 100 strings per batch using the quantity slider. For larger datasets, generate multiple batches and combine them. The CSV export includes indexing to help track large sets.
Can I export as CSV for Excel?
Yes! The CSV export creates a table with Index, Value, and Length columns. Perfect for importing into Excel or Google Sheets. You can then sort, filter, or analyze your generated data.
Is this useful for software testing?
Extremely! Generate edge-case test data matching your validation rules. Test phone number validators with 1000 valid numbers, or stress-test email parsers. The Regenerate button creates new batches instantly for varied test cases.