Hi there. That's cool idea. I think that you can use the @regexhq organization to get regexps.
Purpose behind RegexHQ is to learn, share and collect regular expressions - as much as possible.

Maybe is a feature, but for me should be generic so that it validates all "valid" dates.
It doesn't work if you try to validate: "01/01/2100"

HTML Tags
/^<([a-z1-6]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)$/

Famous answer

Hex Value
/^#?([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$/

Hex HTML/CSS color value maybe, but 0xDEADBEAF is a perfectly valid hex value.

Password
/^[a-zA-Z0-9+_-]{6,32}$/

Slowly we're moving the world to password phrases and everybody should be hashing their passwords. Then why the 32 char limit? And why, for Pete's sake, are we only allowing a-zA-Z0-9+_- and nothing else? *cries* (see also)

Email
/^([a-z0-9+_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,24})$/

Yeah. Just. No. Another famous answer

Positive number
/^\d*\.?\d+$/

We don't all live in the US/UK. (1,234.56 v.s. 1.234,56)

Phonenumber
/^\+?[\d\s]{3,}$/

+123 is a valid phonenumber? Where? Phonenumbers are notoriously hard to validate (hence libphonenumber for example).

Date in format dd/mm/yyyy
/^(0?[1-9]|[12][0-9]|3[01])([ \/\-])(0?[1-9]|1[012])\2(19[0-9][0-9]|20[0-9][0-9])$/

Failed the very first 'edge case' I could come up with: 30/02/2016 but also 1852 or 2150 fail... ( as noted elsewhere).

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. - Jamie Zawinski

dont have time to submit pull req, but this regex checks for IP validity, can provide 1 IP addr or a range, ie

192.168.5.100-192.200.20.255

^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$|^.*-,{3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$

you can check it here
https://regex101.com/

Also for email, this regex is more encompassing
^[a-zA-Z0-9_.+-]@[a-zA-Z0-9_.+-].[a-z][a-z][a-z]

Steps to Reproduce :

• Go to RegEx Site
• Go to 'Time in 24-hour format' section and enter the test string as : 22:33
• Observe that the output returned is : 22
• The RegEx can be : /^([01]?[0-9]|2[0-3]):([0-5][0-9])$/ in order to give the minutes value in the output

Expected Result
The RegEx for 'Time in 24-hour format' should give minutes value in the output

Actual Result
The RegEx for 'Time in 24-hour format' does not give minutes value in the output

it does not display single digit minutes in time it is because it is compulsary for 1st digit to be 0 to 5. if user enter minutes without 0 it does not work you can fix this by using this regex /^([01]?[0-9]|2[0-3]):[0-5]?[0-9]$/

Hi Luke,

Nice project, I guess you already know regex101.com, so maybe sharing your regexes in its library would be cool, also allowing people to go directo to their editor/tester.

Here's one of mine: https://regex101.com/r/It4QGm/1
For currency parsing.

Atm. it seems that you only do a check for https://. Maybe you should think about adding http too

It should allow the user to type in whatever he/she wants. Why? Because they might be using password generators and this regex:

/^[a-zA-Z0-9+_-]{6,18}$/

... is limiting them to use only a small subset of characters and that is not a good practice. I think it should also allow to type in longer text, instead of 18, I would use for example 32.

Steps to Reproduce :

• Go to RegEx Site
• Go to HTML tags section and enter the test string as, HTML Heading tag : <h1>Heading</h1> (this is one of the valid tags as per W3 School site)
• Observe that the output returned is null
• The RegEx should be : /^<([a-z][1-6]+)([^<]+)(?:>(.)</\1>|\s+/>)$/ in order to match the HTML Headings tag

Expected Result
The RegEx for HTML tag should match all the HTML tags

Actual Result
The RegEx for HTML tags does not match the HTML headings tags

I find I frequently need a regex for dollar amounts, for example: \d*(\.\d{1,4})?

Would this be something that would make sense to add?

What steps do I take to run this locally?