There are many synonyms for the phrase "without assistance." Some examples include "unaided," "independently," "solo," "on your own," "single-handedly," "self-reliantly," "unassisted," and "unsupported." Each of these terms implies that the person or thing is doing something without the help of others or outside support. These synonyms can be used in a variety of contexts, such as describing a person's ability to perform a task, or a device's capability to function without human intervention. Regardless of the context, the use of these synonyms helps to convey the idea of self-sufficiency and resourcefulness.