regex101: Email Address Validation

Pro

\Astart of string

Non-Capturing Group(?:(?=[a-zA-Z0-9])(?=[\w@\-.]{1,128}\z)(?=[\w.-]+[a-zA-Z0-9]@)[\w-]+(?:\.[\w-]+)*@(?:[0-9a-zA-Z][-\w]*[0-9a-zA-Z\.]){1,2}[a-zA-Z]{2,9})

Positive Lookahead(?=[a-zA-Z0-9])

Character Class[a-zA-Z0-9]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Positive Lookahead(?=[\w@\-.]{1,128}\z)

Character Class[\w@\-.]{1,128}

{1,128}matches between 1 and 128 characters from the set below:

\wany word character

@the literal @ (64₁₀ / 100₈ / 40₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\zend of string

Positive Lookahead(?=[\w.-]+[a-zA-Z0-9]@)

Character Class[\w.-]+

+matches at least one character from the set below:

\wany word character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[a-zA-Z0-9]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Character Class[\w-]+

+matches at least one character from the set below:

\wany word character

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:\.[\w-]+)*

*repeats the group contents below any number of times:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[\w-]+

+matches at least one character from the set below:

\wany word character

-the literal - (45₁₀ / 55₈ / 2D₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Non-Capturing Group(?:[0-9a-zA-Z][-\w]*[0-9a-zA-Z\.]){1,2}

{1,2}repeats the group contents below between 1 and 2 times:

Character Class[0-9a-zA-Z]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

Character Class[-\w]*

*matches any number of characters from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\wany word character

Character Class[0-9a-zA-Z\.]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-zA-Z]{2,9}

{2,9}matches between 2 and 9 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\zend of string

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

25 tokens

Regular Expression

\A(?:(?=[a-zA-Z0-9])(?=[\w@\-.]{1,128}\z)(?=[\w.-]+[a-zA-Z0-9]@)[\w-]+(?:\.[\w-]+)*@(?:[0-9a-zA-Z][-\w]*[0-9a-zA-Z\.]){1,2}[a-zA-Z]{2,9})\z

Regular Expressions 101

Regular Expression

Unit Tests