regex101: JavaScript Match Workspace

^start of line

Negative Lookahead(?!.*?_.*?)

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

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

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

Negative Lookahead(?!(?:[\w]+?\.)?\-[\w\.\-]*?)

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

?repeats the group contents below at most once:

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[\w\.\-]*?

*?matches any number of characters from the set below:

\wany word character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?![\w]+?\-\.(?:[\w\.\-]+?))

Character Class[\w]+?

+?matches at least one character from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

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)

Positive Lookahead(?=[\w])

Character Class[\w]

\wany word character

Positive Lookahead(?=[\w\.\-]*?\.+[\w\.\-]*?)

Character Class[\w\.\-]*?

*?matches any number of characters from the set below:

\wany word character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.+the literal . (46₁₀ / 56₈ / 2E₁₆) , repeated at least once

Character Class[\w\.\-]*?

*?matches any number of characters from the set below:

\wany word character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?![\w\.\-]{254})

Character Class[\w\.\-]{254}

{254}matches exactly 254 characters from the set below:

\wany word character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?!(?:\.?[\w\-\.]*?[\w\-]{64,}\.)+?)

Non-Capturing Group(?:\.?[\w\-\.]*?[\w\-]{64,}\.)+?

+?repeats the group contents below at least once:

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[\w\-\.]*?

*?matches any number of characters from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[\w\-]{64,}

{64,}matches at least 64 characters from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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)

Negative Lookbehind(?<![\w\-\.]*?\.[\d]+?)

Character Class[\w\-\.]*?

*?matches any number of characters from the set below:

\wany word character

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[\d]+?

+?matches at least one character from the set below:

\da digit

Positive Lookbehind(?<=[\w\-]{2,})

Character Class[\w\-]{2,}

Negative Lookbehind(?<![\w\-]{25})

$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

Search reference

Regular Expression

^(?!.*?_.*?)(?!(?:[\w]+?\.)?\-[\w\.\-]*?)(?![\w]+?\-\.(?:[\w\.\-]+?))(?=[\w])(?=[\w\.\-]*?\.+[\w\.\-]*?)(?![\w\.\-]{254})(?!(?:\.?[\w\-\.]*?[\w\-]{64,}\.)+?)[\w\.\-]+?(?<![\w\-\.]*?\.[\d]+?)(?<=[\w\-]{2,})(?<![\w\-]{25})$

Unit Tests

There are no unit tests, click to add some.