Migrating from different wikis to Confluence is not a easy task . I made some searches around however I did not found any free "click and migrate" solution.
Just for a background in the past there was an add called (UWC) that would help with that:
It was not very easy to use and is only compatible with 4.3.7 ( also very outdated).
For this specific task I would really advise you to reach atlassian experts for a custom migration:
Experts services are subject to a quote.
I know it's a paid service, but depending on your current scenario, that would be the safest and easy option to achieve this migration.
Do you use templates with Confluence? Take part in a remote 1-hr workshop. You'll receive USD $100 for your time! We're looking for people to participate in a remote 1-hr workshop...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs