# Define the vars or files that you want to compare:

vars:
  - json1: {'a': 1, 'b': 2}
  - json2: {'b': 3, 'c': 4}

# Use it into your playbook and define the original and the compared:

- name: Run and test the diff json module
  diff_json:
    original: "{{ json1 }}"
    compared: "{{ json2 }}"
  register: diff

- name: Debug the full output
  debug:
    msg: "{{ diff }}"

- name:
  debug:
    msg:
    - "This is the original message {{ diff.original_json }}"
    - "This is the message to compare {{ diff.compared_json }}"
    - "This is the comparison {{ diff.comparisons }}"