regex101: Match Gmail Email

Pro

^start of line

Character Class[a-z0-9]+

+matches at least one character from the set below:

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

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

Negative Lookahead(?!.*(?:\+{2,}|\-{2,}|\.{2,}))

.*any character (except for line terminators), repeated any number of times

Non-Capturing Group(?:\+{2,}|\-{2,}|\.{2,})

1st Alternative\+{2,}

\+{2,}the literal + (43₁₀ / 53₈ / 2B₁₆) , repeated at least 2 times

2nd Alternative\-{2,}

\-{2,}the literal - (45₁₀ / 55₈ / 2D₁₆) , repeated at least 2 times

3rd Alternative\.{2,}

\.{2,}the literal . (46₁₀ / 56₈ / 2E₁₆) , repeated at least 2 times

Non-Capturing Group(?:[\.+\-]{0,1}[a-z0-9])*

*repeats the group contents below any number of times:

Character Class[\.+\-]{0,1}

{0,1}matches at most one character from the set below:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[a-z0-9]

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

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

@gmailthe literal text @gmail (case insensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

comthe literal text com (case insensitive)

$end of line

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

25 tokens

Regular Expression

^[a-z0-9]+(?!.*(?:\+{2,}|\-{2,}|\.{2,}))(?:[\.+\-]{0,1}[a-z0-9])*@gmail\.com$

New

niceandsimple@gmail.com
very.common@gmail.com
disposable.style.email.with+symbol@gmail.com
other.email-with-dash@gmail.com
invalid--email@gmail.com
invalid++email@gmail.com
invalid..email@gmail.com
-invalid-email@gmail.com
invalid--email-@gmail.com

Substitution

niceandsimple@gmail.com
very.common@gmail.com
disposable.style.email.with+symbol@gmail.com
other.email-with-dash@gmail.com
invalid--email@gmail.com
invalid++email@gmail.com
invalid..email@gmail.com
-invalid-email@gmail.com
invalid--email-@gmail.com