I would recommend Scribophile
Scibophile is a writing critique site based around earning points and then spending them to have others review your work. While there is a paid option to the site, this allows you to save more of your writing on the site but does not in a huge way impact your ability to get critiques.
The basic idea of the site is that in order to have others read your stuff you have to read theirs. On average you have to be ready to read and critique about three times more text than you are going to submit. In return, you are almost guaranteed to have at least 3 people read your work and leave meaningful feedback. Feedback quality is controlled by length, and not useful feedback can be flagged to regain your points. Other users also review critiques allowing you to get some feedback of what users think of other user's suggestions.
A challenge of submitting to Scibophile is that each submission should be around 3000 characters. For some of my writing, it was very hard to break it up into such chunks. Fortunately, the community is good and will often follow your work reading parts as you post them.
Overall I have found that not only have I received good feedback from the site, but giving feedback to other authors has helped me sharpen my skills as it made me be able to more keenly analyze my own writing.