I want to generate slug for some strings without going through WordPress slug generation flow. Therefore, I want to know which functions it calls to get a neat slug. I tried sanitize_title() but it leaves %c2 %a0 in result.

4 Answers 4


You are almost there. The function you need is sanitize_title_with_dashes( $title )

  • 2
    While this definitely appears correct, I'm a little unclear what sanitize_title_with_dashes seems to do differently to sanitize_title. sanitize_title is also adding dashes where whitespace is...
    – Tim Malone
    Commented Jul 24, 2015 at 2:31
  • 12
    If you check the WordPress Codex for sanitize_title_with_dashes( $title ), you will see the note 'it does not replace special accented characters' which means characters like èäç etc. will stay in place with this function.
    – JHoffmann
    Commented Aug 26, 2015 at 8:43
  • 1
    Please note that sanitize_title_with_dashes as well as sanitize_title leave some special characters that may break some systems. I you want a more universal approach in reducing strings take a look at sanitize_html_class
    – GDY
    Commented Feb 27, 2019 at 15:01
  • This answer is wrong, as explained in the comments, and the author should update it, perhaps best pointing to a more correct answer like wordpress.stackexchange.com/a/294587/27896 Commented Jun 12 at 20:18

sanitize_title() seems to be the only one you need.

In wp-includes/default-filters.php line 211 you will find:

add_filter( 'sanitize_title', 'sanitize_title_with_dashes', 10, 3);

This means that calling sanitize_title() will first remove all the special characters, then apply the sanitize_title filter, thus calling sanitize_title_with_dashes()

As @JHoffmann pointed out, simply calling sanitize_title_with_dashes() will not remove special characters.

  • 3
    This should be the correct answer
    – bysanchy
    Commented Jul 23, 2018 at 8:14

Well, there is already an answer, but I wanted to expand it a bit, so here are my findings:

If we have a look in wp_insert_post() we see, the $post_name is sanitized using wp_sanitize_title() ( see wp-includes/post.php)

In the function sanitize_title() we have a filter sanitize_title. This is interesting, since in the default filters sanitize_title_with_dashes() is hooked into this filter (see wp-includes/default-filters.php).

echo sanitize_title( 'Â+ÄÖßáèäç' ) // aaeoessaeaec

I tried sanitize_title() but it leaves %c2 %a0 in result.

This sounds strange. It would be great to know the input value, but following wp_insert_post() sanitize_title() seems to be enough.


In addition to websupporter's great answer I found the below:

Depending on your usage it will depend what you need.

sanitize_title() as it says:

accents are removed (accented characters are replaced with non-accented equivalents)

...and sanitize_title_with_dashes says:

Note that it does not replace special accented characters

So, with this example string: Â+Ä Ö %%% ßá %20 oo %pp + -_^^#@!**()=[]|\/\'"<>?``~ èäç

sanitize_title() result:


As you can see it has replaced accented characters with their non-accented equivalents and it has removed all other non-alphanumeric characters apart from the % which is followed by a number, but you will see it was removed when it was followed by a letter; perhaps this is because it perceives it as already encoded. This is enforced when you try inserting %c3 into your string, it doesn't strip it as %c3 is a valid encoding sequence.

sanitize_title_with_dashes result:


So as you can see it hasn't removed the accented characters, but encoded them.

Now let's look at a string with no accented characters to see how they both behave...

Example String: %%% building %20 oo %pp + -_^^#@!**()=[]|\/\'"<>?``~'

sanitize_title() result:


sanitize_title_with_dashes result:


So as you can see they are exactly the same. So it appears the only difference in them is that one encodes accented charters whilst the other replaces them.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.