There are two similiar but distinct filters that can be used to escape literal or special characters.

• regex_escape
• urlencode (this article)

urlencode can be used to encode special characters in a string. In this example, the whitespace in "fo o" is encoded as %20.

---
- hosts: localhost
  tasks:
  - name: encode special characters
    debug:
      msg: "{{ 'fo o' | urlencode }}"
...

The following should be returned.

ok: [localhost] => {
    "msg": "fo%20o"
}

In this example, the long dash (also known as em dash) in ba–r will be encoded.

---
- hosts: localhost
  tasks:
  - name: encode special characters
    debug:
      msg: "{{ 'ba–r' | urlencode }}"
...

The following should be returned.

ok: [localhost] => {
    "msg": "ba%E2%80%93r"
}