Can I turn my open source side project into a profitable thing?

A couple of years ago I built a tool for programmers. It was well received by users, and till now it has more than 23,000 downloads. It's free to use and open source.

I've been thinking of how can I turn it into profitable project.

My plan so far is:

• Keep the current version as a free version.
• Build a paid Pro version with more advanced features.
• I want to keep the current version open source as it is, just for educational/historical purposes, but all the new features will be close source.

Any opinions on this?