Is this a simple sentence or a fragment?

Doesn’t need help.

Also why?

There is no subject. What do you think it is?

Please study about sentences here, especially if your text is unclear.
https://academicguides.waldenu.edu/writingcenter/grammar/sentencestructure

To determine whether the given statement "Doesn’t need help." is a simple sentence or a fragment, we need to understand their definitions.

A simple sentence is a complete sentence that contains one independent clause, which means it can stand alone as a complete thought. It typically consists of a subject, a verb, and expresses a complete idea.

On the other hand, a fragment is an incomplete sentence that does not express a complete thought, usually lacking a subject, a verb, or both.

In the given statement, "Doesn’t need help.", we can identify that it has both a subject and a verb. The subject is "Doesn’t" (which is a contraction of "does not") and the verb is "need." Additionally, it expresses a complete thought, indicating that someone or something is not in need of assistance.

Based on these observations, we can determine that the statement "Doesn’t need help." is a simple sentence.