Useful RegEx snippets that are categorized and searchable (see below)

• Contributions are welcome! Please read our CONTRIBUTING, CODE_OF_CONDUCT, and LICENSE files to get started. RegEx snippet ideas are located in IDEAS.md.
• Errors? Submit an issue, or even better, submit a PR fixing the issue!
• RegEx snippets are either user-created, or picked from across the web.

• Dates
  • Match mm/dd/yyyy
  • Match mon/dd/yyyy
  • Match month names
• Files
  • Match image filenames
• Miscellaneous
  • Match city, state abbreviation
  • Match credit cards
  • Match email addresses
  • Match US Phone Numbers
  • Match valid hexadecimal colors
  • Match social security number
  • Match ZIP Codes (5 digit and 9 digit)
• Numbers
  • Match dollar signs and comma separators in a number
  • Matching leading zeroes
• Strings
  • Match new lines
  • Match strong passwords (At least one lower case, one upper case, one number, one special character, and 10 characters long)
  • Match usernames (alphanumeric string of a certain length)
• Web
  • Extract URL from an anchor tag
  • Match all content within a specific HTML tag
  • Match all HTML tags
  • Match IPv4 Addresses
  • Match Twitter usernames
  • Match URLs
  • Match URL safe strings
  • Match URL slugs

Match mm/dd/yyyy
Accepts mm/dd/yyyy, mm-dd-yyyy, or mm.dd.yyyy and doesn't care about leading zeroes.

/^[0-3]?[0-9](\/|\.|-)[0-3]?[0-9](\/|\.|-)[1-9]\d{3}$/gi

Match mon/dd/yyyy
Accepts mon/dd/yyyy, mon-dd-yyyy, or mon.dd.yyyy and doesn't care about leading zeroes or case. For example, will match "jan/10/2017"

/^(jan|feb|mar|apr|may|jun|jul|aug|sept?|oct|nov|dec)(\/|\.|-)[0-3]?[0-9](\/|\.|-)[1-9]\d{3}$/gi

Match month names
Accepts month names (both full and abbreviated), and doesn't care about case. For example, it will match "January" and "jan".

/^(jan(uary)?|feb(ruary)?|(mar)?ch|(apr)?il|may|(jun)?e|(jul)?y|(aug)?ust|sep(tember)?|sept|(oct)?ober|(nov)?ember|(dec)?ember)$/i;

Match image filenames

/^.+\.(jpg|jpeg|png|gif|bmp|svg)$/gi

Match city, state abbreviation (Matches "Los Angeles, CA" for example)

/[a-zA-Z\s]*, [A-Z][A-Z]/

Match credit cards (Make sure to strip the string of all commas, spaces, etc. before matching)
Amex:

/^3[47][0-9]{13}$/

Discover:

/^65[4-9][0-9]{13}|64[4-9][0-9]{13}|6011[0-9]{12}|(622(?:12[6-9]|1[3-9][0-9]|[2-8][0-9][0-9]|9[01][0-9]|92[0-5])[0-9]{10})$/

Mastercard:

/^5[1-5][0-9]{14}$/

Visa:

/^4[0-9]{12}(?:[0-9]{3})?$/

Visa Mastercard:

/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14})$/

Match email addresses

/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/i

Match US Phone Numbers
Matches ###-###-####, (###) ###-####, and ### ### ####

/^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$/

Match valid hexadecimal colors

/^#([0-9a-f]{3}$|[0-9a-f]{6}$)/i

Match social security number
Matches ###-##-####

/^[0-9]\{3\}-[0-9]\{2\}-[0-9]\{4\}$/

Match ZIP Codes (5 digit and 9 digit)

/^[0-9]{5}(-[0-9]{4})?$/

Match dollar signs and comma separators in a number: This can be used to strip a number string into an actual number.

/(\$|\,)/g

Matching leading zeroes:

/^0{2,}/g

Match new lines

/[\r\n]|$/g

Match strong passwords (At least one lower case, one upper case, one number, one special character, and 10 characters long):

/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$@$!%*?&_])[A-Za-z\d$@$!%*?&_]{10,}$/

Match usernames (alphanumeric string of a certain length):
Replace MIN_CHARS and MAX_CHARS with the minimum and maximum length of the username, respectively.

/^[a-z0-9]{MIN_CHARS,MAX_CHARS}$/i

Extract URL from an anchor tag
For example, if str = "<a href = 'https://www.google.com' ></a>", this RegEx would return "https://www.google.com".

str.match(/<a\s+(?:[^>]*?\s+)?href ?= ?["']([^'^"]*)["'][^>]*>/i)[1]

Match all content within a specific HTML tag (Replace "p" with whatever tag you want)

/<p>(\n|.)*<\/p>/gi

Match HTML tags

/<\/?[^>]+>/g

Match IPv4 Addresses

/^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/

Match Twitter Usernames

/^@?(\w){1,15}$/

Match URLs

/((([A-Za-z]{3,9}:(?:\/\/)?)(?:[\-;:&=\+\$,\w]+@)?[A-Za-z0-9\.\-]+|(?:www\.|[\-;:&=\+\$,\w]+@)[A-Za-z0-9\.\-]+)((?:\/[\+~%\/\.\w\-_]*)?\??(?:[\-\+=&;%@\.\w_]*)#?(?:[\.\!\/\\\w]*))?)/

Match URL safe strings

/^[a-zA-Z0-9_-]*$/

Match URL Slug

/^[a-z0-9-_]+$/i