How to check if a URL is valid

Question

How can I check if a string is a valid URL?

For example:

http://hello.it => yes
http:||bra.ziz, => no

If this is a valid URL

Answer 1

For me, I use this regular expression:

/^(http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$/ix

Option:

• i - case insensitive
• x - ignore whitespace in regex

You can set this method to check URL validation:

def valid_url?(url)
  return false if url.include?("

To use it:

valid_url?("http://stackoverflow.com/questions/1805761/check-if-url-is-valid-ruby")

Testing with wrong URLs:

• http://ruby3arabi - result is invalid
• http://http://ruby3arabi.com - result is invalid
• http:// - result is invalid
• http://test.com\n