We give improved and almost optimal testers for several classes of Boolean functions on n inputs that have concise representation in the uniform and distribution-free model. Classes, such as k -Junta, k -Linear Function, s -Term DNF, s -Term Monotone DNF, r -DNF, Decision List, r -Decision List, size- s Decision Tree, size- s Boolean Formula, size- s Branching Program, s -Sparse Polynomial over the binary field and functions with Fourier Degree at most d .