Regex Tester - Free Online Tool

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Regex Validation

Regular expression:

Global Ignore case

Test string:

Match results:

Regular expression	Description	Actions
`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`	Match a standard email address
`^\+?[1-9]\d{1,14}$`	Match an international phone number (E.164 format)
`^(https?:\/\/)?([\da-z.-]+)\.([a-z.]{2,6})([\/\w.-])\/?$`	Match a standard URL
`^(25[0-5]\|2[0-4]\d\|[01]?\d\d?)\.(25[0-5]\|2[0-4]\d\|[01]?\d\d?)\.(25[0-5]\|2[0-4]\d\|[01]?\d\d?)\.(25[0-5]\|2[0-4]\d\|[01]?\d\d?)$`	Match an IPv4 address
`^(\d{4})-(0[1-9]\|1[0-2])-(0[1-9]\|[12]\d\|3[01])$`	Match a date in YYYY-MM-DD format
`^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$`	Match a UUID (version-agnostic)
`^([01]\d\|2[0-3]):[0-5]\d$`	Match a time in 24-hour HH:MM format
`^(?:4[0-9]{12}(?:[0-9]{3})?\|5[1-5][0-9]{14}\|3[47][0-9]{13}\|6(?:011\|5[0-9]{2})[0-9]{12})$`	Match common credit card numbers (Visa, MasterCard, American Express, Discover)
`^[a-zA-Z0-9_]{3,16}$`	Match a username (3-16 letters, digits, or underscores)
`^(?=.[a-z])(?=.[A-Z])(?=.\d)(?=.[@$!%?&])[A-Za-z\d@$!%?&]{8,}$`	Match a strong password (at least 8 chars with upper/lowercase letters, digits and special characters)
`^[a-zA-Z]+$`	Match alphabetic letters only
`^[1-9]\d*$`	Match a positive integer (excluding zero)
`^-?\d+(\.\d+)?$`	Match integers and decimals (including negatives)
`<[^>]+>`	Match an HTML tag (including angle brackets)
`^[a-z0-9]+(?:-[a-z0-9]+)*$`	Match a URL slug (lowercase, hyphen-separated)
`^#?([0-9a-fA-F]{3}\|[0-9a-fA-F]{6})$`	Match a hex color code (3 or 6 digits)
`^\d{4}\s\d{4}\s\d{4}\s\d{4}$`	Match a bank card number with spaces (16 digits in groups of 4)
`^[A-Z]{1}[A-Z]{1}[A-Z0-9]{4}[A-Z0-9]{1}$`	Match a vehicle license plate number
`^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$`	Match a MAC address (colon or hyphen separated)
`^\d+(\.\d{1,2})?$`	Match a number with up to two decimal places

About This Tool

The Regex Tester is a powerful online tool for testing and validating regular expressions, with a library of common patterns for email, phone numbers, URLs and more.

For a step-by-step deep dive, read our guide: How to Test a Regular Expression Online.

Features

Regex Testing

Test regexes in real time, highlight matches, and get match statistics.

Common Patterns

Quickly find common regex patterns for email, phone numbers, URLs and more.

Regex Validation

Validate regex syntax and surface errors.

Local Processing

Everything runs locally — your data is never uploaded.

Tips

Use `g` for global matching and `i` for case-insensitive; verify in real time with the input toggles.
Prefer anchors `^` and `$` to match whole lines and avoid false matches.
Watch greedy vs. lazy quantifiers: `*?`, `+?`, `{m,n}?` help avoid over-matching.
Escape special characters: `.`, `[`, `]`, `(`, `)`, `{`, `}`, `?`, `+`, `*`, `|`, `^`, `$`, `\\`.
Prefer character classes and boundaries: `\d`, `\w`, `\s`, `[A-Za-z]`, `\b` for clarity.
Groups and backreferences: use `()` to group; capture groups are useful for replace or stats.
Test strings can be multi-line; enable global matching to return and highlight all matches.
Local processing: all matching and copying happen in your browser; nothing is uploaded.

Example: extract text inside parentheses (non-greedy)

\((.*?)\)

How to use the Regex Tester

1.Type your regular expression in the pattern field.
2.Paste the text you want to match against.
3.Set flags like case-insensitive or global if needed.
4.Review the matches highlighted in real time.

Regex Tester FAQ

What is a regular expression?

A regular expression (regex) is a pattern that describes a set of strings, used to search, match, and extract text in code and data.

What do the flags do?

Flags change matching behavior — for example, case-insensitive matching or a global search that finds every match instead of just the first.

Why isn't my regex matching?

Common causes are unescaped special characters, missing anchors, or greedy versus lazy quantifiers. Try escaping reserved characters like . * + ? | and test small pieces at a time.

Is my test data sent to a server?

No. The regex engine runs in your browser, so the text you test against never leaves your device.