Regular Expressions Guide for Beginners - Learn Regex in 10 Minutes

What Are Regular Expressions?

Regular expressions (regex) are patterns used to match character combinations in strings. They're incredibly powerful for text search, validation, and manipulation.

Basic Patterns

Literal Characters

The simplest regex is just a plain string: hello matches "hello" in any text.

Special Characters (Metacharacters)

Character	Meaning	Example
.	Any single character	h.t matches "hat", "hot", "hit"
^	Start of string	^Hello matches "Hello world"
$	End of string	world$ matches "Hello world"
\d	Any digit	\d{3} matches "123"
\w	Word character (a-z, A-Z, 0-9, _)	\w+ matches "hello"
\s	Whitespace	\s+ matches spaces, tabs

Quantifiers

Quantifier	Meaning
*	Zero or more
+	One or more
?	Zero or one
{n}	Exactly n times
{n,m}	Between n and m times

Practical Examples

Email Validation

[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

Phone Number

\d{3}[-.\s]?\d{3}[-.\s]?\d{4}

URL Pattern

https?://[\w.-]+\.[a-zA-Z]{2,}[/\w.-]*

IP Address

\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}

Character Classes

• [abc] - Matches a, b, or c
• [a-z] - Matches any lowercase letter
• [^abc] - Matches anything except a, b, or c
• [0-9] - Same as \d

Groups and Alternation

• (abc) - Capturing group
• (?:abc) - Non-capturing group
• a|b - Matches a or b

Test Your Regex

Practice makes perfect! Use our free Regex Tester to test your regular expressions in real-time with instant match highlighting.