Character set

In user/config.php the setting YOURLS_URL_CONVERT defines what characters short URLs will use.

36 or 62, nothing else

This rather cryptic setting defines the character set used for your short URL "keywords" (the abc12 part in https://sho.rt/abc12):

  • with 36: lower case alphanumeric, i.e. allowed characters are 0123456789abcdefghijklmnopqrstuvwxyz
  • with 62: mixed case alphanumeric, i.e. allowed characters are 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

Nerd explanation

The number represent the "base" a sequential or random number will be converted in. Base 36 has 36 characters (10 digits + 26 latin alphabet letters), base 62 has 62 characters (10 digits, 26 lower case and 26 upper case latin letters)

Short URLs will comply to this character set

When you create a new short URL with a custom keyword, any character not in the list will get removed. Examples:

  • with 62, if you create a short URLs with keyword OMG@🤒ozh♛! it will become OMGozh (non alpha numeric stripped)
  • with 36, short URL keyword OMGozh will become ozh (non lower case alpha numeric stripped)

But I want to use a custom character set

You want to restrict your short URLs keywords to, say, 12345abcde? No problemo. That's why YOURLS has a plugin architecture, so you can use and make plugins to make it work the way you need. See Plugins.


We suggest you:

  • do not change this setting after you're created some short URL
  • use latin character for your keywords