If your Confluence site is open to the public (you allow anonymous users to add comments, create pages etc) you may find that automated spam is being added, in the form of comments or new pages.
You can configure Confluence to deter automated spam by asking users to prove that they are human before they are allowed to:
- Add a comment.
- Create a page.
- Edit a page.
- Send a request to the Confluence administrators.
Captcha is a test that can distinguish a human being from an automated agent such as a web spider or robot. When Captcha is switched on, users will see a distorted picture of a word, and must enter it in a text field before they can proceed.
By default, Captcha is disabled. When enabled, the default is that only anonymous users will have to perform the Captcha test when creating comments or editing pages. You can also choose to enforce Captcha for all users or members of particular groups. You can raise a support request to have Captcha turned on in your instance if you have allowed anonymous users to comment or create content in Confluence. See Compare Atlassian cloud vs server for more information.